Document 6512530

I
H o w to
R e d u c e Your
Energy Costs
.......................................
.......................................
The Energy Efficiency Guide
.....................................................................
..........................................................................................
for Businesses, Industry,
...................................................................................................................
...................................................................................................................
Government and Institutions
COMPLIMENTS OF
The Vermont Department of Public Service
ENERGY EFFICIENCY DIVISION
ME
energy efiiciency and
energy savings!
The familiar T-I 2 fluorescent
tube and the slimmer, more
efficient T-8 that is replacing it.
This guide will introduce you to the technology
that can greatly boost the efficiency of your energy systems-such as the T-8 fluorescent.
Just as this slim, more efficient new light source can help you
trim your energy costs, there are many other ways your bottom
line can benefit from new energy products and techniques.
You will also learn about the many proven ways to maintain and
operate your energy systems to save energy dollars year after year.
And many of these are low-cost or no-cost ones that you can do
yourself!
So, join the many thousands of building owners and tenants who
are reaping the benefits of energy management. By selecting the
methods that suit your particular needs, you will be able to control and even substantially reduce your energy use and costs.
Contents
ENERGY AND Y O U R B O T T O M LINE
5
How You Can Profit From Energy Savings
6
Tracking Costs and Making Changes
8
Investing In Energy Improvements
SAVINGS OPPORTUNITIES
11
LIGHTING
27
BUILDING ENVELOPE
33
HVAC - Heating, Ventilating, Air Conditioning
45
HOTWATER
51
MACH IN ES
SIX I M P O R T A N T T H I N G S T O DO
@ R50/P10
Printed on paper containing
50% recycled fibers, including
10% post-consumer waste
Using recycled paper helps
the environment, saving energy,
water, and trees, nature's defense
against the greenhouse effect.
62
Check Out Your Building (Walk-Through Audit)
66
Make Operation and Maintenance Work for You
67
Consider an EMS
68
Save When You Build
70
Explore Ways to Reduce Your Electric Bills
72
Get Your Action Plan Under Way
A publication of Advantage Publications and Insights,
11 Beacon Street, Boston MA 02108. Copyright 0 1996
Insights Incorporated, all rights reserved. This puhlication, in whole or in part, may not he reproduced by any
mechanical, photographic, or electronic process or in
the form of a sound recording, nor may it he stored in a
retrieval system, scanned, simulated, transferred, transmitted or otherwise copied for public or private use
without prior written permission from the publisher.
The information contained herein is believed to be
accurate and reliable at the time of printing. Neither the
authors, publisher, technical advisors, nor those who
may distribute this publication are to he held accountable for the suitability of recommendations or for the
performance of a system design, product, or procedure
in particular applications, nor is there any liability if
possible levels of energy savings are not actually
achieved. Furthermore, reference to trade names or specific commercial products, commodities or services
does not constitute an endorsement, recommendation
or favoring. Readers should thoroughly investigate any
design, procedure, or product and independently con-
clude suitability or satisfactory performance before purchase or use.
We gratefully acknowledge, for this edition, staff of the
following organizations for their interest, review, and
helpful suggestions regarding form and content: Detroit
Edison, Florida Power & Light, Jacksonville Electric
Authority, North Carolina Electric Membership
Cooperatives, Northern States Power, PECO
(Philadelphia Electric), and West Penn Power. They
add to and build upon the second edition contributions
of Southern California Edison, Ontario Hydro, Orange &
Rockland, Ohio Edison, Public Service Company of
Colorado, Dayton Power and Light, and New York State
Electric And Gas. We also thank the Bonneville Power
Administration, Southern California Edison, Mass Gas
and Electric of Boston, Association of Independent
Universities and Colleges, Nathan Miller Properties,
and Fred Davis Corporation for their cooperation in
relation to photos and graphics.
Consultantsfor this edition: David Adamian, HEC;
Walter E. Henry, P.E., Xenergy; Michael W. Tennis,
Union of Concerned Scientists; and Carl M. Watson,
P.E., Applied Energy Solutions.
Third Edition, 1996.
0 NOW, to see what you can d o to reduce energy use through
proper maintenance and operation.
0 BEFORE YOU BUY any energy related products-light
bulbs,
a new air conditioning unit, etc.
0 JUST BEFORE YOU D O YOUR BUDGETING FOR NEXT YEAR,
to see if there are energy-related expenditures you should be
making, even borrowing to do. Some may be very good investments.
0 BEFORE YOU TALK TO YOUR MAINTENANCE PERSONNEL.
They should have a chance to read the book, too.
0 BEFORE YOU REMODEL, ADD O N TO YOUR BUILDING,
OR BUILD A NEW ONE.
Your Bottom Line
This Book Can Save You Thousands
...
Put yourself in the picture it’s easy!
Effective energy management can save you hundreds or
even thousands of dollars-every year! And in many cases
the things you need to do are very simple and take very little time. Spend an hour reading this book, and see how
many ways you can save energy dollars.
ENERGY: Who Pays?
Check those you pay:
Electricity Gas or Oil
Interior Lighting
Exterior Lighting
Heat
Air C o n d i t i o n i n g
H o t Water
“Process” Energy
(for machines)
Other
Excellent investment possibilities
Investing in energy efficiency improvements can yield
excellent returns in the form of energy dollar savings. This
book explains many capital investment projects and shows
you how to judge whether a particular investment is a
good one.
Whether you own or rent,
you can boost your bottom line
Energy management is not just for building owners. If you
rent, chances are you pay your own electric bills and perhaps gas or oil bills as well.
ENERGYAND YOUR BO77OM LINE
How You Can Profit From Energy Savings
Looking at your
"bottom line"
Whatever your energy expenditures,
trimming them will boost your bottom
line, or enable you to spend more on
needed salary increases or other expenses. Energy costs may be such an important expenditure for you that they actually equal or exceed profits! In such a
case, a do-able 30% decrease in energy
expenditures will mean that profits will
increase by at least a like amount! You
may find that careful energy management is your easiest route to increased
profitability!
ENERGY
PROFITS
ments as part of your next lease, either
as improvements to your present space
or building or as part of the "build-out"
in your new one. Your landlord may go
along with it as an inducement to have
you sign on-and you will reap the benefits of the day-to-day operating energy
savings!
Do you renovate or build,
and then re-sell?
If you build or renovate for purposes of
resale, you will want to make your
building energy efficient. Since buyers
of buildings and commercial condominiums increasingly look at energy costs as
part of the building "package," if you
can show your building to be more energy-efficient than its competition it
should sell faster, more easily, and more
profitably. And, as one of the handful of
People determining the energy efficiency of our building stock, you will have
contributed to the economic and environmental well-being of your area and
the country as a whole.
The 9 Steps to
Saving Energy Dollars
Are you a tenant?
Even if you are not the building owner,
you may pay a significant amount in
energy costs. Use the checklist at the
right to identify which energy costs you
pay; it will help you determine which
sections of this guide will be most helpful to you.
In addition to making no-cost
changes such as turning off lights when
they are not needed, you may find that
your lease is long enough or the savings
great enough to justify your investing in
some improvements-for example,
installing a T-8 fluorescent lighting system. And some of your best improvements may be portable ones that can be
taken with you at the end of your
lease-e.g., task lights or compact fluorescent bulbs.
Finally, don't be reluctant to try to
negotiate energy efficiency improve-
1. Read this handbook.
2. Find out last year's energy use and cost.
3. Do an energy "audit."
4. Get some expert help with the audit if you need it.
..
5. Ask co-workers for ideas.
and listen to their concerns about health and comfort.
6. List possible projects, costs, and savings.
7. Decide the top priority things to do.
8. DO them
- with outside help if needed.
9. Keep track of savings.
5
ENERGYAND YOUR B O n O M LINE
Tracking Costs and Making Changes
How much energy do you
use, and how much are you
paying for it?
These are important questions, because
the answers will give you the “baseline”
for calculating potential savings.
To get the figures you need, collect
your energy bills for the last calendar
year and the first part of this year. Use
the worksheet on the next page to record
the monthly totals of both the amount of
energy used and its cost. For a quick
check, or if old bills are not readily
available, your utility company and fuel
dealer may be able to give you totals
from the records for your account.
Record the totals
Fill in last year’s totals in the table titled
“My Energy Use and Costs.” Since energy prices may have changed, you will
want to enter the current prices, too, so
you can calculate savings as you use
this guide. If you pay for electricity at a
declining block rate (see p . 701,you will
want to note the cost per kWh at the
lowest rate you pay, since the savings
you achieve will usually be at that rate.
Also see page 70 for an explanation
of demand charges, which may be an
important item on your electric bills.
If your energy use has been somewhat erratic and you can expect the
same kinds of variations to crop up in
the future, a three-year average may be
more useful to calculate a “norm.” If
your operation has been growing or contracting, you may want to pay attention
to an average annual use per employee,
per square foot of area, per unit of product, per hour of operation, or some other
variable that would enable you to relate
your energy use to changes in size or
level of activity.
Keep track of progress as this year
goes by. Use the same worksheet to
enter the new figures each month, and
see how your energy management
efforts are paying off.
My Energy Use and Costs
Last Year’s Totals
cost
Use
Electricity -energy
-demand
Natural Gas
kWh
-S
$-
per kWh
kW
$-
$-
per kW/month
$-
$-
per ___
gallons $
$-
per gallon
$-
per
--
UNITS“
Heating Oil
Other
-$-
Current Prices*
(cost per unit)
UNITS
UNIT”
~
UNIT
* Consult your utility company and fuel dealers.
*’ The gas unit used by your utility may be a “therm” or “ccf“ (hundred cubic feet) or ‘7”(thousand cubic feet).
Energy management pays
even if energy prices fall
No matter what the unit prices are for
energy, it pays to use less. If prices fall,
you may not save quite as much, but it
still can be a substantial amount (see
examples below). And many efficiency
improvements produce savings year
after year with no additional effort. If
prices rise, of course, you stand to
benefit even more from increased
energy efficiency.
Energy Management
Always Pays
If your energy
costs have been
running $5,000
a year, and you
assume:
Your annual savings
if you reduce energy
consumption by:
20%
30%
10%
Prices stable
$500
$1,000
$1,500
Prices fall 20%
400
800
1,200
Prices rise 20%
600
1,200
1,800
6
How to make changes that
save energy
In your present space there are many
ways to reduce your energy consumption.
Operation & Maintenancethings as easy to do as turning off lights,
setting thermostats at more economical
heating or cooling levels, changing filters in air conditioners. A great many of
the methods discussed in this guide are
no-cost or low-cost “O&M”changes in
how you use or maintain your present
energy systems, and they can save you a
great many energy dollars.
Retrofits-modifications such as new
thermostats, high efficiency motors,
rewired lighting, installation of window
films or insulation. Some of these efficiency improvements to your present energy
systems cost relatively little to do, others
require more investment dollars. Yet paybacks can often be fast, with subsequent
energy savings continuing for many years.
If you will be involved in new construction, be sure to consider such
things as weather-wise building design
and orientation, adequate insulation, the
most efficient lighting fixtures and controls, and maximum use of daylight.
Even a thoughtfully designed new addition or “build-out” of a modest office
suite from raw space offers you the
chance to design in, “from scratch,” a
high degree of energy efficiency. See p .
68 for the basics of this exciting subject.
ENERGYAND YOUR BOTTOM LINE
Codes and beyond
There often are state and local code
requirements for building construction,
modification, and operation. Look for
construction or building codes specifying such things as insulation and lighting levels and health and occupancy
codes for dishwasher water temperatures, ventilation rates, and other
requirements.
Some codes are energy-conscious and
can help keep down your energy consumption, but most minimum code
Productivity, health, and comfort
Energy use is closely tied to people’s
productivity, health, and comfort. Too
much or too little heating, cooling, or
lighting, for instance, can make workers
ELECTRICITY
ENERGY USE (kWh)
USE
LASTYEAR
January
February
March
April
May
June
July
August
September
October
November
December
TOTAL
requirements fall far short of the energy
savings you can achieve. Make sure you
consider “going beyond the code” for a
design or system-say, a new lighting
system-that achieves even greater energy efficiency than the levels mandated
by the code.
THISYEAR
unproductive, customers unresponsive,
visitors or other occupants uncomfortable. Fortunately, there are many ways
to reduce energy consumption and costs
without adversely affecting anyone. And
some improvements, such as reducing
glare and over lighting, can actually add
to people’s health and productivity as
well as save energy costs.
Hire an expert
An expert’s fee can be an excellent energy investment-see more on page 8.
GAS OR OIL
UNITS (
DEMAND (kW), if any
m LASTYEAR
LASTYEAR
THISYEAR
THISYEAR
)*
m
-
*Gallons of oil or therms or ccf (hundreds of cubic feel) or mcf (thousands of cubic feel) of natural gas
COST
ELECTRICITY COSTS
FOR (kWh) USED
DEMAND CHARGES, if any
LAST YEAR
THISYEAR
LASTYEAR
January
February
March
April
May
June
July
August
September
October
November
December
TOTAL
7
THISYEAR
m
GAS OR OIL COSTS
FOR FUEL USED
LASTYEAR
THISYEAR
m
ENERGY AND YOUR BO77OM LINE
Investing In Energy Improvements
Some of the ways to reduce energy use are
no-cost things you can do yourself- resetting thermostats, making sure lights or
machines are off when not needed, changing to new energy efficient fluorescent
tubes, etc. Other energy saving measures
may require some investment for new
equipment, some expert help, or both.
Hire an expert
Probably the best way to spend your
investment dollars is to hire an expert:
to analyze those parts of your energy
systems which you don’t understand;
to explain possible energy savers,
including changes in control settings,
modifications to your lighting, and
new controls or equipment that
would be more efficient;
to estimate potential costs and energy
savings; and
to actually adjust your existing
equipment to save you energy dollars
immediately--tor cxample, testing
and tuiiiiig vour HVAC eqiiiprnc:nt.
Experts in the energy field Probably Will
be listed in the yellow pages, or your
utility or your business or professional
associates may be able to make some
recommendations. Expect to Pay a lump
sum fees
a multiple Of an
charge, and be sure to ask in advance:
what their services will include;
what you may expect to save; and
whether they will give you a written
report (a “must”).
Also be sure to ask the expert to refer
you to other clients, then call them to
find out what kinds of savings the
expert has helped them to achieve.
The reason that expert analysis and
tuning can be so worthwhile is that a
few relatively simple adjustments, that
you wouldn’t know how to make, can
save you 2 % , 5%, 10% or more on your
energy bills. This could amount to hundreds and even thousands of energy
dollars saved every year, with no
investment on your part except the
energy expert’s fee.
Capital investment for
new equipment or contro(s
This manual emphasizes ~ow-costand
no-cost eiit:rgy wving ninthods. There
are somo uroit:c:ts, however. that can bc
done only with substantial capital
investment. These projects are listed in
each section and may include your
“big” project (for example, replacement
of an obsolete boiler) which you should
consider most seriously because it alone
I
would result in the greatest reduction in
your energy use.
As investments go, some energy
improvement projects provide extraordinaryreturns. In fact, they may be by
far the best use of your available capital
and even justify your borrowing in
order to undertake them. For example,
an investment of $1,000 that yields
energy savings of $1,000 a year will pay
for itself in one year and by the end of
the second year will have netted you
$1,000in energy costs avoided. Over 3
years it would yield $2,000, over 4 years
$3,000, and over 5 years, $4,000.
The first thing you are interested in is
the length of time for an investment to
pay for itself in energy savings (or costs
avoided). The simplest way to calculate
this is the simple payback method.
Divide the installed cost of the improvement by the annual energy savings; the
result is the payback period, in years.
>
Cost of eight
occupancy
sensors,
installed
Annual
energy savings
-~$480
-
$240
= 2years
For more precise figures, first subtract any rebates from the cost of the
improvement and also subtract any
operating costs from the annual energy savings.
8
ENERGY AND YOUR BO77OM LINE
If the payback period is long, or if
you want to see if a particular energy
conservation project would yield as
high a return as some other investment,
you may want to do a more comprehensive life cyclehate of return analysis.
Here is what you need to know:
Annual savings (first year)-make
this conservative.
Cost of improvement (including
likely maintenance and replacement
costs over its useful life).
The ratio of the cost to the savings
(how many times greater the cost is
than the savings)-for example, a
$500 investment that saves $100 a
year is 5:1, or 5x (the cost is 5 times
the savings).
How long the improvement will
last- conservative.
What you will assume to be future
energy price increases per year.
What interest rate you must pay if
you borrow, or what rate of return
you want if you use your own capital.
Then the calculation is easy.
Example
Annual savings
$100
Cost of improvement
$600
Ratio of cost to savings
6x
Improvement will last
10 years
Energy prices will go u p 0% a year
My interest rate or rate
of return
10%
Payback Periods (if you assume energy prices will not change)
If the cost of the improvement is -times the
1st year savings:
Payback period in years if you borrow at, or want a rate of
return on your investment of:
6%
8%
ioyo 1 2 ~ ~14%
16%
iw0 20%
1.06
2.19
3.14
4.71
6.12
7.66
9.35
11.22
13.33
15.73
18.51
21.85
25.99
31.45
39.52
55.24
never
lx
2x
3x
4x
5x
6x
7x
8x
9x
1ox
llx
12x
13x
14x
15x
16x
17x
1.08
2.27
3.57
5.01
6.64
8.50
10.67
13.27
16.54
20.91
27.55
41.82
never
1.13
2.42
3.94
5.77
8.09
11.23
16.17
29.86
never
1.11
2.34
3.74
5.36
7.27
9.61
12.63
16.89
24.1 8
never
1.15
2.51
4.16
6.27
9.19
13.99
29.86
never
* "Never" means annual interest charges are equal to or exceed annual energy savings (costs avoided)
Turning to the table, by going down the
left-hand column to 6x and reading
across, you can see that the payback
period is over 9 years. Your conclusion:
a possibly risky investment, since the
life of the improvement is only 10
years.
Whether borrowing or using your
own capital, you may decide on a larger
investment than the table would suggest if the energy improvement has a
longer life than the investment period.
This is because energy savings are
"pure gravy" once the capital is repaid,
and this long-term benefit may justify
your accepting a lower rate of return
during the first few years.
9
-\
,
,
1.17
2.60
4.41
6.88
10.84
21.89
never
1.20
2.70
4.69
7.69
13.91
never
1.22
2.80
5.03
8.83
never
Opportunities
LIGHT1N G
ENVELOPE
HVAC
HOT WATER
MACHINES
77
27
33
45
57
Now that you know how much energy you use and what
you pay for it, you will want to understand your energy
systems and the various possibilities for savings. The following pages are designed to help you.
Then do a walk-through of your own building or space,
perhaps with an expert. Use the book and the self-audit
forms on pages 61-65 to see how and where energy is being
used - and to start to spot the savings opportunities.
Don't Miss These 10
Many of the fastest and easiest ways to save energy will cost you
little or nothing. In fact, you may get 50% or more of your energy
savings by doing these I O :
1. Turn off lights when not needed.
2. Remove unneeded light bulbs.
3. When replacing bulbs, use lower wattage or more efficient ones.
4. Lower your heating settings.
5. Raise your air conditioning settings.
6. Reduce heating and air conditioning during unoccupied hours.
7. Turn off heating and air conditioning somewhat before the end of
your operating hours.
8. Have your heating, ventilating, and air conditioning systems
serviced and adjusted.
9. Turn off machines and equipment when not needed.
I O . Make sure all automatic controls are in good working condition
and are set properly.
Y
our lighting probably should be the first place you look
for potential energy savings. Changes are often very easy
to make, and a good many of them cost little or nothing
to do. This section of the guide will show you lots of
ways to get more from your lighting energy dollar.
How lighting can waste energy
Lighting energy can be wasted in several ways, by:
Inefficient light sources-when the lamp” or fixture is
inefficient in converting electricity to light, using more watts
(units of electric power) than necessary to produce the lumens
(units of light output];
Transmission losses-when dirt or some other obstruction blocks some of the light; or when the light source is too far
away from what you want illuminated;
Over lighting-when more light is used than is needed or
when a “free” source such as daylight is not used; and
Excessive “on” hours-when lights are on for no reason
(e.g., when no one is there).
Four major ways to save
As you will see, getting the most for your lighting dollar often
involves:
turning lights off when they’re not needed;
reducing light levels wherever there is more light
than is needed;
installing more efficient lighting or controls;
doing proper maintenance to minimize light losses.
How much light is enough
12
No-cost projects
13
Low cost and investment projects
16
Other lighting improvements
18
19
Compact fluorescents
20
Fluorescent lighting
Reflectors, other incandescents 21
* “Lamp”is the general term used for a light
bulb, fluorescent tube, or other light source.
Other high efficiency lighting
22
New controls and rewiring
23
Other projects
25
Savings tables
26
LIGHTING
How much light
is enough?
Save 20% or more
with little effort
You may need light for a wide range of
different areas and needs-inside, for
offices, work areas, restrooms, classrooms, sales or reception areas, to name
just a few-and outside, for signs, exits,
parking areas, and perimeter safety and
security. For each area or need, there
must be enough light of the right quality.
Lighting usually offers an easy and
rewarding way to save energy dollars:
savings of 20% to 50% are commonplace!
For instance, removing j u s t one 100watt light bulb can save over 200 kWh*
of electricity every year; removing five
such bulbs would save over 1,000 kWh!
You would also save the cost of replacing burned out bulbs (an average conventional light bulb used eight hours per
business day will last only six months).
Check Table 2 to see what removing
those five bulbs would save you on your
electric bills.
“Demand” savings. Reducing the
amount of electricity you use for lighting may also reduce your peak demand.
If you are billed for both energy use
(kwh) and demand (kW),you may
achieve additional savings [see p . 70).
Air conditioning savings. Since
lights generate waste heat, improved
lighting efficiency can lower your air
conditioning costs, too. * * But remember
that your principal savings will come
from lower electric bills for operating
the lights.
Do a “walk-through”
Take a close look at each area to see what
the lighting needs really are. Ask people
how they feel about the lighting: is there
too much or too little light, is there glare?
If you want to check people’s impressions and your own, you can measure
the amount of light with a light meter
(ask your lighting supplier to lend you
one). You can then compare your present lighting levels to nationally accepted recommendations; see Table 1 for
some examples. Light level recommendations are based on the difficulty of the
seeing task, contrast, and other factors.
When measuring levels with a meter,
be sure to take into account whatever
contribution daylight is making (remember that you need adequate lighting on
overcast days and perhaps at night, too).
Light levels are measured at “task level,”
which will vary - for example, at the
Taking the guesswork out of light level measurements: above, inset, a photocell light
meter, placed on the work surface or other
area being lighted. At right, a more accurate
electronic meter that uses a sensor and
displays footcandles on its LED screen.
desk top. Light levels in corridors should
be measured at floor level.
Possibly do the walk-through
with an expert
A lighting expert can help you achieve
both maximum savings and maximum
visual comfort. And if you are going to
“retrofit” with new lamps, fixtures, or
controls, the expert can help guide you
through the wide array of options,
avoiding those which would be inappropriate for your needs.
* 100 watts x 8 hours a day x 5 days a week x 52
weeks a year equals 208,000 watt hours + 1,000
equals 208 kilowatt hours [kWh).
* * Although these savings are partially offset by
increased heating loads in the heating months.
Table 2
Table 1
Some Recommended Lighting Levels*
Yearly Value of Electricity Saved
Lighting Level
(footcandles)
Your
electricity
cost per
kWh:
1-5
5-1 0
10-20
20-50
50-100
100-200
Examples of areas or activities
Outdoor walkways
Restaurant dining areas
Reception areas, lightly used office areas
Typical office work
More demanding visual tasks (office or shop)
- e . g . , reading telephone book
Especially difficult visual tasks-low contrast,
very small size, or requiring high accuracy.
Source: Based on IES recommendations.
* Fora more extensive list of recommended light levels for specific tasks. see the IES Lighting Handbook,
published by the Illuminating Engineering Society, 345 East 47th Street, New York, NY 10017.
12
Value of the electricity saved
if the number of kilowatt hours
used per year is reduced by:
500 1,000 2,500 5,000
10,000 25,000
5d
$25
$50
$125
$250
$500
$1,250
7t
35
70
175
350
700
1,750
9t
45
90
225
450
900
2,250
llt
55
110
275
550
1,100
2,750
1%
65
130
325
650
1,300
3,250
1st
75
150
375
750
1,500
3,750
176
85
170
425
850
1,700
4,250
1%
95
190
475
950
1,900
4,750
LIGHTING
No-Cost Projects
However, “delamping” may not
always be the right thing to do in an
area where light levels seem too high.
For instance, if you remove lamps near
windows, will there still be enough light
on overcast days or at night? Besides
delamping, other solutions to consider
include: installing dimmers or additional
light switches, and relamping with lower
wattage lamps [see later in this section).
‘\
\\
Removing fluorescents
Remove unneeded lamps
Lighting levels often are higher than
necessary-because many buildings
were designed and built in an era when
energy efficiency was not a high priority.
A simple way to save energy dollars
is to remove unneeded lamps where
lighting levels exceed-your needs.
By removing lamps with careful
attention to the type of activity, occupants’ needs, and light distribution, you
may be able to reduce lighting costs substantially without affecting the comfort
or productivity of the people there. As
Table 3 shows, simply removing
unneeded lamps can be very rewarding!
Remove pairs. In two-lamp and
four-lamp fluorescent fixtures, lamps
are usually wired in pairs and therefore
must be removed in pairs (both lamps in
a pair stop working when one is
removed). In common fox-lamp fixtures, you have the choice of removing
either the two outer-most lamps or the
inner pair. When removing lamps in a
highly visible ceiling, you may want to
remove the same pair (inner or outer)
from each fixture to achieve an aesthetically pleasing, uniform lighting pattern
for the ceiling.
Try it out. Remove two of the
lamps in the four-lamp fixtures, and see
if the remaining standard lamps yield
enough light for your needs. If they
don’t, you might try relamping with two
brighter, triphosphor T-12 or T-10
lamps-ask your dealer.
Disconnect the ballasts.
Fluorescent fixtures include components called ballasts which provide
proper voltage and current for starting
and running the lamps. Ballasts themselves use electricity when the fixture is
turned on: a typical rapidstart ballast
for two 40-watt lamps can use between
8 and 16 watts. If the two lamps are
removed but their ballast is not disconnected, the ballast will continue to use
up to 6.5 watts when the fixture is
switched on.
For maximum energy dollar savings
when removing lamps, disconnect the
ballasts as well. Table 11 on p. 26
shows you the savings.
Table 3
Yearly Energy Dollar Savings from Removing 75-Watt Lamps
Your
electricity
cost per
kWh:
Disconnecting a ballast is a relatively
simple electrical wiring job, but it is
best done by a licensed electrician.
Your annual savings in electricity costs
if you remove this number of 75-watt lamps:
16
24
48
$78
$156
$234
$ 468
27
109
218
328
655
35
140
281
421
842
43
172
343
515
1,030
51
203
406
608
1,217
59
234
468
702
1,404
66
265
530
796
1,591
74
296
593
889
1,778
2
8
$20
Note: Savings are calculated to the nearest dollar, Assumes lights are used 52 weeks a year, 50 hours a week (5 days a week, averaging 9 hours a
day, plus 5 hours for a half-day or for cleaning).
13
Proper lamp and
ballast disposal
Fluorescent lamps contain mercury,
and some older ballasts contain PCBs.
Both are classified as hazardous
waste and require proper disposal.
The recommended procedure for
lamp disposal is recycling. See p. 18
for ballast disposal. Your state energy
office or recycler can recommend a
certified recycler.
LIGHTING
Turn off lights when an
area is unoccupied
Use partial lighting before
and after “public” hours
Lights should be turned off whenever an
area is left unoccupied for any length of
time. For instance, when people go to a
meeting or to lunch, they should turn
off the lights for their own work space.
Similarly, unless security is an issue,
people leaving restrooms or storage
areas unoccupied should “flick the
switch.” Consider using a label or sign
next to the light switch to remind people to turn it off. (Also see Occupancy
Sensors, p . 24.)
While the life of a fluorescent lamp
can be shortened if it is turned on and
off frequently, remember that energy
cost savings far outweigh the cost of these
lamps during their lifetimes. The balance
point here is from about 10-20 minutes,
so lights should be turned off if nobody
will be in the office for that amount of
time or longer. .
Remember also that mercury vapor,
metal halide, and sodium lamps take
longer to light than fluorescent and
incandescent lamps, and often must wait
as long as 15 minutes afier being turned
off before they can begin to produce any
light output (restrike) again. If you will
need the light immediately, this delay
must be taken into account when making
a decision to turn these lights off.
There may be times when employees
must work in an area but the “public”
isn’t there. A good example is a store
before and after it is open to customers,
when shelves are stocked, merchandise
is rearranged, and cleaning is done.
Employees may need to move freely and
safely through the entire area, but full
lighting is not needed because it’s not
selling time.
If you have enough control of lights
with a bank of switches, you may be
able to turn on, say, half the lights and
provide enough light throughout the
area. To calculate the potential lighting
energy savings, simply figure the cost of
running the lights the way you do now
for the total hours of this kind of use per
year, and divide by two (for half lighting). (Seep. 23 for an example of savings.)
Turn off lights near
windows
If your lights can be controlled separately, turn off those nearest the windows
whenever there is enough natural light.
If you have shades or blinds that can
be opened, the sun they let in will also
add warmth and reduce the load on
your heating system in winter. On the
other hand, this solar heat can be
unwanted in summer; but you may find
that so much electricity can be saved by
switching off lights that it will pay to
install special film, shades or blinds to
reduce heat transmission yet let the natural light in during the warm months.
Re-schedule or reduce
evening activities
Cleaning hours are often evening hours,
when lights are turned on only for this
purpose. Sometimes, because of the
wiring and switches, a very large area or
perhaps an entire floor must be lighted
even though only part of it is being
cleaned at a time.
If vou can’t rewire, to the extent possible re-schedule evening cleaning to daylight times, such as a weekend day, when
the area is unoccupied.
rn a few
there may be evening
meetings or other activities which can be
re-scheduled to daytime. But frequently
the best that can be done is to make sure
the evening activity is in an area of the
right size or, if need be, in a larger area
where the lights can be controlled so
that only those needed are used.
Review your
outside lighting needs
You may have lighted parking areas,
signs, entrances, walls, and landscaping.
You may be able to turn off some of this
lighting if you find it is not needed, or
use it fewer hours, or use lower wattage
lamps. (See more on controls on the
next page and page 24).
Use only necessary safety
and security lighting
At night and when areas are unoccupied, make sure the only lights left on
are those needed for safety, security, or
some other specific purpose.
In the daytime, make sure that parking area lights and perimeter security
lighting are not on.
Code Compliance. Be sure to comply
with any code requirements for safety
and security lighting, such as for exit
signs, stairway lighting, and other emergencY lighting.
LIGHTING
Make sure
automatic controls
are working properly
Some of your lighting may be controlled
by a time clock which switches the
lights off and on automatically at predetermined times which you select. Just an
hour or two a day of unnecessary lighting, say, in your parking area, can add
up to substantial energy costs that could
be avoided by assuring the timer is
doing its job properly.
Make sure the timer is set accurately
and completely. First, it must coincide
with the actual time of day (and if there
is ever a temporary power disruption, be
sure to reset your timer after power has
been restored, unless it has a “memory”).
Secondly, it must have all its “pins,”
and they must be placed properly. A typical mechanical seven-day time clock has
two movable pins for each on/off cycle;
so, properly set for aweek it should have
as many as seven pairs of pins, each pair
in the correct positions to control the
lights for one day. Make sure no pin is
missing or in the wrong position.
Third, make sure that the timer is
properly re-set during the year to take
into account seasonal changes in natural
lighting, weekends, holidays, and daylight savings time.
Another common type of control,
used mostly for outdoor lighting, is acti-
vated by a photocell. It turns lights on
when it grows dark and automatically
adjusts for seasonal variations in daylight hours. Make sure this control is
working properly.
Are you getting all the
light you’re paying for?
A maintenance “must”: keep lamps and
fixtures clean. Dust, grease, and other
dirt accumulations on lamps, lenses,
globes, and reflecting surfaces of the fixture can reduce light output by as much
as 30%! Lighting professionals recommend that you clean your light fixtures
every two or three years. In greasy,
dusty, or smoky settings, or when light
fixtures are integrated with the HVAC
system, cleaning may need to be more
frequent.
When you do your lighting “walkthrough,” check to see how clean the
lamps and fixtures are, and do any necessary cleaning before deciding on efficiency changes in the lighting. Cleaning
will increase the light output and may
allow you to remove some lamps or to
install lower wattage ones.
To maintain your lighting efficiency
gains, cleaning is particularly important.
If you have reduced light levels in previously over-lighted areas, timely cleaning
will assure you of continuing to have
enough light for the needs of each area.
A properly set time clock ensures lights are on
only when needed. This model is for lights,
such as security lights, used at the same time
daily; 7-day models permit daily variations you
might need for parking lot lights, other illumination.
15
Consider
“group relamping”
The lumen output of fluorescents
decreases as they age, yet the same
amount of energy is consumed to produce this lower level of light. Timely
replacement of old lamps will eliminate
this inefficiency and assure you of getting full lighting value for your energy
dollar.
A practice that is becoming quite
common among building owners and
tenants with a large number of ceiling
lights is group relamping, or replacing
all lamps in an area near the end of their
useful life. It can cut lamp replacement
labor costs in half when efficiently done
by a team going from fixture to nearby
fixture, and it can assure proper light
levels. It will also help prevent unwanted interruptions in work or some other
activity when individual lamps burn out
at random.
LIGHTING
Low-Cost and Investment Projects
Federal EPACT law assures availability of
more efficient products
Once you have done the basics covered
in the last few pages, you should consider modifying your lighting. Selecting
which modifications to make will
depend on your specific conditions,
such as the existing lighting levels, the
tasks or types of areas which must be
lighted, and your economic criteria.
Many lighting efficiency projects
require only a small outlay. In other
cases, a more substantial investment is
needed, but savings in energy costs often
produce returns that are more than competitive with the best investments in the
financial market. Before you invest, calculate the payback period and consider
life cycle costs to see if the project will
be a sound investment (see p p . 8 9 ) .
Try it out before committing to major changes
Many of the energy improvements suggested in this booklet are difficult to try
out before you make the installation. A
new boiler, for instance, isn’t something
you can try out in advance, in your own
building, to evaluate how well it works.
Lighting, on the other hand, gives you
this opportunity. Be sure to try out different kinds of lamps and different wattages,
and if you are about to install new fix-
Because of the standards set by the
passage of EPACT (the Energy Policy
Act of 1992), suppliers’ shelves are
increasingly filled with more energy
efficient products. Many of the old
familiar lighting stand-bys, such as
the single-phosphor-coatedcool
white F40T12 four-footer which has
been the most common fluorescent
for many years, are no longer being
manufactured or being imported.
Passage of this law is stimulating
greater activity on the part of manu-
facturers to develop and market efficient products, and it makes part of
the upgrading of your system semiautomatic, as you find only more efficient replacements of your less efficient lighting components available.
But there are still many choices for
you to make among the improved
products, to assure the most efficient,
cost-effective lighting improvements
and new installations. Once again,
getting expert help in making your
selections will be a wise move.
Partial Listing of Discontinued* Lamps
FLUORESCENT
INCANDESCENT
4-foot F40T12CW and D
75R30/FL and SP
4-foot F40T12WW and WWX
75PAR/FL and SP
U-shape FB40CW/6 and WW/6
75R/FL and SP
8-foot F96T12CW and WW
150R/FL and SP
8-foot F96T12CW/HO and WHO
15OPAR/FL and SP
*Lamps whose specifications do not comply with the requirements of EPACT and which are no longer being manufactured. Note that more efficient models of many of these lamps are available in the same wattages, although there are
many substitutes which yield similar amounts of light yet are more energy efficient.
tures throughout your space try one or
two first and see how you like them.
Since lighting is so important in terms of
ambiance, comfort and productivity, it’s
fortunate this testing is possible.
A word about codes
There may be state or local codes with
lighting efficiency requirements you
must meet for new construction or
remodeling. Some codes set limits in
terms of watts per square foot of build-
76
ing area (for example, maximum two
wattslsq. ft.). Make sure you meet the
code requirements-but don’t stop
there. The code will define the minimum acceptable level of energy efficiency, but you should be able to design
your new lighting to meet your needs
with even greater efficiency and electric
bill savings!
LIGHTING
which will determine how your area
looks (e.g.,cool versus warm), and they
have different color rendition capabilities that affect how “true” colors of
objects, skin, etc. will appear. True color
rendition is especially important for
such needs as effective merchandise displays (e.g., food in a supermarket or
restaurant, or clothing or other goods in
a store) and for properly rendering hair
color and makeup in a salon.
The newer, more efficient fluorescents are now offered in the most widely
used color temperatures, with either of
two levels of color rendering. Your dealer can help you make the right choice.
FLUORESCENT
CEILING LIGHTING
There are three ways to reduce the
amount of energy used by your fluorescent ceiling lighting: install lower wattage
or more efficient lamps; replace the ballasts; or retrofit or replace the fixtures.
Install lower wattage or
higher efficiency lamps to
replace standard ones
With the changes brought about by
EPACT (see page 1 S), and the old standby
standard 40 watt cool white and warm
white lamps no longer in production, your
choices include several types of more energy-efficientand lower wattage fluorescents.
While some of the replacement lamps
may yield slightly less light, this may be
acceptable since in many areas you may
have more light than you need [see page
12). Furthermore, when clean new lamps
are installed, and the diffuser and reflecting surfaces of the fixture are cleaned,
there may be an increase in light output
even with lower wattage. However, it will
be important to keep the fixtures clean to
maintain acceptable light levels.
Installing lower wattage or higher
efficiency lamps can be the easiest way
to reduce energy consumption in ceiling
lighting. Unless replacing ballasts is.
required (see right), all it takes is a ladder, the new lamps, and something to
clean the fixtures with.
Selecting the right lamps. When
selecting new fluorescent lamps, ask
your supplier to make sure they are
compatible with the existing ballasts
(although it may be cost-effective to
replace the ballast as well-see below).
For example, 32-watt T-12s or 34 watt
T-12s should not be used with pre-1979
ballasts, because it will shorten lamp
life by as much as 50%.
T-12s.* Without changing a post-1979
ballast, standard four-foot, 40-watt rapid
start lamps (F40-T12)can be replaced
with 32-watt T-12 or 34-watt T-12 lamps
that save 15-20% in energy with slightly
* The number after the “T”represents eighths
of an inch: a T-I2 is one and one-half inches in
diameter, a T-8 is one inch.
Four footers (from top): T-12 40-watt cool
white fluorescent, no longer in production;
energy-saving T-12 34-watt and 32-watt lamps;
and higher efficiency T-8 32-watt lamp.
reduced light output. 32-watt T-12
replacements should not be used in fixtures that will be switched on and off frequently. If you need more light than a
standard 34 or 32 gives, there are T-12
triphosphors which have higher lumen
(light) output.
T-8s. Although it is possible to
replace T-12s with other T-l2s, many
lighting experts feel that installing the
higher efficiency, slim T-8 32-watt
lamps is a better solution when replacing standard T-12s. T-8s must be
matched with appropriate ballasts (T-12
ballasts don’t match), so if using a fixture which previously used T-12s the
ballast must be replaced. T-8s and electronic ballasts (as opposed to less efficient magnetic ones) are considered the
best combination. Installing 32-watt T-8s
with new ballasts to replace your 40-watt
lamps will save you energy dollars with
little or no reduction in light output:
with an electronic ballast, a T-8 lamp will
actually draw only 25-28 watts.
8-footers. There are energy-efficient
replacements for the discontinued standard eight-footers, too, both in the T-8
and T-12 formats.
*A note about color. Fluorescent
lamps come in many varieties, not only
in wattage and size but also in color.
They have different color temperatures,
17
Replace present lamps
even before they burn out!
If your fluorescents are used infrequently, it may not pay to install the new
energy-efficient lamps until the old ones
have burned out.
Usually, however, with lighting that
is used a lot, you can justify installing
the new lamps even if the old ones still
work! So much energy may be saved
that its value will soon offset the cost of
the new lamps. This is true even if your
present standard lamps are relatively
new. Since the life of a fluorescent is as
much as 20,000 hours, it might take up
to I O years to wear out a recently
installed standard fluorescent, during
which time you would use extra electricity worth considerably more than the
cost of a replacement lamp.
If you have a storeroom filled with
brand new standard T-12s, keep them in
their wrappers and dispose of them
properly, rather than install them in
your ceilings.
What to do when you have many
newer standard T-12s in the ceiling:
Replace them with lower wattage T12s (see next page for an example
of lamps with 5 years left] or, possibly better still, retrofit the fixtures
with T-8s and electronic ballasts.
LIGHTING
ciency, like the one below: Look for it
on replacement ballasts and on the ballasts in new fixtures you buy.
Install more efficient
ballasts when replacing
burned out ones
The ballast is an integral, energy consuming part of a fluorescent or HID fixture. It provides proper starting and running voltage and current for the lamps.
A ballast draws power when the fixture
is switched on and is an important determinant of the energy efficiency of the
entire lighting system.
Magnetic ballasts. Current Federal
standards require that manufacturers
increase the efficiency of the magnetic
ballasts they produce for use in four-foot
and eight-foot fluorescent fixtures. So,
any replacement ballast you buy is likely to be more efficient than the burned
out one.
Ballasts that meet the standard have
a certification label with an “E” for effi-
Cathode cut-out or hybrid ballasts.
These premium magnetic ballasts provide nearly the same efficiency as an
electronic ballast. These may be appropriate where you have very sensitive
electronic equipment.
Electronic ballasts. The Federal
standard only establishes a minimum
acceptable ballast efficiency level. For
the highest efficiency, you can buy an
electronic ballast that uses even less
power than a magnetic one. There are
electronic ballasts for all the common
types of fluorescent tubes. This type of
~~
Why it pays t o replace lamps that still work
__
-.
_.
~~~
~~
This example uses 4-fOOt fluorescent lamps; the same sort of analysis works for any lamp replaced with
a more efficient one.
Old lamp
New lamp
40 watts
x
34 watts
a hrs/day
320 watt hours/day (0.32 kWh/day)
x 8 hrs/day
272 watt hours/day (0.27 kwhlday)
0.27 kWh/day
0.32 kWh/day
x 260days/yr
x 260days/yr
70.2 kWh/yr
83.2 kWh/yr
x 5 years
x 5 years
351 kWh
416 kWh
65 kWh SAVED over 5 years
Net savings if electricity
5C/kWh
7C/kWh
$3.25
$4.55
-1.50*
-1.50‘
$1.75
$3.05
costs:
9$/kWh
$5.85
-1.50*
$4.35
11$/kWh
$7.15
-1 50‘
$5.65
l3$/kWh
$8.45
-1.50*
$6.95
15f/kWh
$9.75
-1.50*
$8.25
17$/kWh
$11.05
-1.50*
$9.55
19$/kWh
$12.35
-1.50*
$10.85
‘112 cost of new lamp: assumes lamp lasts 20,000 hours, if used 2,000 hourslyear over 10 years.
In addition, you may save demand charges on your electric bill.
This is a simplified example of life cycle costing, which takes into account the cost of equipment, its useful life, energy consumed, and the cost
of that energy. This example does not, however, factor in possible changes in the cost of equipment or energy, or financing costs if required.
A possibly better alternative: a T-8 lamp and ballast retrofit
ballast reduces both lamp flicker and
waste heat generation. Dimming ballasts are also now available in electronic versions, for those situations requiring a variable amount of light.
Important note: Ballasts last a long
time. Replacing ballasts that are still
working is often one of the most cost
effective energy improvements. For
instance, installing an electronic ballast
can reduce the energy consumption of a
fixture with two 34-watt lamps from
about 74 watts to about 59 watts (20%)
with no reduction in light output.
Proper ballast disposal
Nearly all ballasts manufactured before
1979 contain PCBs. All manufactured
after July 1, 1978, are required to be
clearly marked “No PCBs”. PCBs are
known to cause skin disorders, liver
damage, skin irritations and reproductive problems. Improper disposal is
environmentally unsound and unlawful; be sure you check your own state’s
requirements, which may be more
restrictive than the following:
Up to 25 PCB ballasts per year may be
disposed of in ordinary landfills unless
the ballasts are leaking. Quantities
greater than that, and leaking ballasts,
are regarded as hazardous waste and
must be disposed of as such. Disposal
options include: chemical waste landfills; whole ballast incineration; and
PCB removal and recycling, the cheapest and most secure method of disposal.
DEHP, now classified by the EPA as a
probable carcinogen, was used in ballasts produced between 1979 and 1991.
Similar disposal methods are recommended for DEHP.
Note: While landfill disposal of
small quantities of PCB ballasts that are
not leaking may be l a ~ uinl your area,
most ballasts are likely to leak in a
landfill in the long run because of corrosion. Therefore, recycling of PCBcontaining ballasts is a more environmentally responsible approach. Your
state energy office or utility can recommend a certified recycler.
LIGHTING
Retrofit the fixtures
Removing unnecessary lamps and in
stalling high efficiency replacements are
easy to do and and can save significant
amounts of electricity. However, with
somewhat more effort and a financial
investment, you can lower your energy
expenditures still further-by “retrofitting,” or modifying, your fixtures.
In some cases, retrofitting your fixtures may be necessary when delamping
or relamping don’t give you sufficient
light output for your needs (many
energy-saving fluorescents also yield
slightly less light.)
Your lighting retrofit may be inspired
as much by the opportunity to
improve productivity as by energy
cost savings. With so many people
What’s included
in a fixture retrofit?
One or more of the following may be the
best for your particular situation:
Installing high efficiency
ballasts. This was discussed above
(see p.15). The new ballasts will use less
electricity, and electronic ones will use
the least.
Installing reflectors that will
“bounce” more light out of the fixtures.
Reflectors may enable you to use fewer
or lower wattage lamps and still achieve
acceptable lighting levels. However, the
light output may be more concentrated
and less even than before; be sure this
will be satisfactory for your needs.
Replacing yellowed or hazy lenses, diffusers, and globes with new ones
that will remain brighter and clearer and
transmit more light. Acrylic is suggested
as the best material for the replacements. Louvers or “egg crate” louver
grids that direct light downward can be
used to prevent reflections onto computer screens; this will decrease overall
light output from the fixture but can
boost productivity because of the
improved lighting quality.
The last two modifications installing reflectors or replacing diffusers - will save you energy dollars
only if the increased light output
enables you to remove some lamps or
use lower wattage ones.
Install new
fluorescent fixtures
Analysis of your lighting needs, present
fixtures, and available new fixtures may
indicate that replacing your present fixtures is the best way to save lighting
energy dollars-and can be an excellent
investment. One of many possibilities for
your fluorescent lighting is a three lamp
T-8 fixture like the one pictured below!
Three lamp fluorescent fixture
T-8 and electronic ballast
now using computers, assuring a comfortable and eye-saving work environment is essential. Reducing background light levels and installing task
lighting for the desktop is the lighting
design approach recommended by the
Illuminating Engineering Society for
offices with video display terminals
(computer screens). By reducing
background light levels to about 35
footcandles (50 to 100 footcandles is
typical) and providing efficient, compact fluorescent desk lights, substantial energy savings can be achieved.
This can also eliminate glare on computer screens.
1
A Note About Harmonics
Many early electronic ballasts, and
other electronic devices as well,
caused harmonics to be created in
the power line. Harmonics are distortions of the standard 60 Hertz
current and voltage wave forms that
create unwanted, and sometimes
very high currents in the neutral
conductors of the building’s wiring
system. Newer electronic ballasts
have been designed to reduce or
almost eliminate these harmonic
currents. Most manufacturers today
produce electronic ballasts with a
“Total Harmonic Distortion” (THD)
of 20% or less. These may be used
without fear of problem-causing
harmonics.
I
’
LIGHTING
OTHER LIGHTING
IMPROVEMENTS
PAR (parabolic aluminized reflectors),
will serve your needs well. One design
that has survived is the ER (ellipsoidal
reflector) featured in the next example.
Install more efficient lamps
in recessed downlights
Install
more efficient lamps
One of the most effective ways to make
lighting more energy efficient is to use
the most efficient lamp that is suitable
for the purpose. The more lumens per
watt, the more efficient the lamp is.
Table 4 shows the relative efficiency of
common types of lamps.
You often see standard light bulbs being
used in recessed downlights. This is
inappropriate, since a standard bulb is
an inefficient lamp for this kind of fixture, radiating light in almost all directions rather than just one. As a result, the
fixture “traps” a good deal of the light.
Rather than a standard light bulb,
a reflector lamp should be used in a
recessed downlight. Because of its
design, a lower wattage reflector lamp
can project the same amount of light as
the higher wattage standard bulb. And
there are some new, even lower wattage
standard reflector lamps on the market,
that may be satisfactory for your needs.
Light projected from recessed downlight
Table 4
Lamp Efficiency
(LEAST efficient)
Standard Incandescent
Tungsten-Halogen
Halogen Infrared Reflecting
Mercury Vapor
Compact Fluorescent
Full Size Fluorescent
Metal Halide
Compact Metal Halide
High Pressure Sodium
Low Pressure Sodium
Standard
bulb
LEAST
“ER
reflector
MOST
Standard
reflector
MORE
Source E P R ~
Using ERs in downlights
Energy savings from installing 50-watt ellipsoidal
reflector (50ER30) lamps to replace 100-watt
standard bulbs in deeply recessed downlights
EPACT and more
efficient products
As explained on page 16, many of the
old familiar incandescent lamps, such
as the R floods and spots, are no longer
in production or being imported,
because of the passage of the Energy
Policy Act (EPACT). Their more efficient replacements, however, such as
~~~
Your cost
Der kWh:
Electricity savings per year from
reDlacina this number
of lamos:
______
__
2
5c
7c
9e
11e
1%
1%
17e
19t
$16
22
28
34
41
47
53
59
24
48
$1 87
262
337
41 2
487
562
636
71 1
$374
524
674
824
973
1,123
1,273
1,423
8
_____
$62
87
112
137
162
187
212
237
NOTES: Energy savings are calculated to the nearest dollar. It is
assumed that: lights are used 52 weeks a year, 60 hours a week
(6 days a week, averaging 10 hours a day) in a reception area.
20
Even standard reflector lamps may not
be the most efficient type, if they are significantly recessed. In a ceiling downlight or
“can” fixture, 50% or more of the light from
a deeply recessed standard flood lamp may
be trapped and the energy wasted.
If the amount of light now being projected is satisfactory, you can save energy dollars by replacing the standard
lamp with a lower wattage “ER” (ellipsoidal reflector) lamp, specially
designed to project much more of its
light out of such a fixture.
With an incandescent ER, energy
costs saved can be very substantial (see
Table 5). If you want more light, you can
try a higher wattage ER lamp or a socket
extender that will bring the front surface
of the standard flood lamp closer to the
opening of the fixture.
As with any change, try some ERs
before totally “buying in.”
Use halogen lamps
where appropriate
Table 5
(MOST efficient)
_ _ ~
Socket extender can bring lamp to front
of recessed downlight.
Another type of incandescent lamp is
available that uses halogen gas to
increase lamp output and prolong the
life of the filament. Halogen light tends
to be sparkling white.
When you need a tight beam, such as
for highlighting a merchandise display,
a reflector halogen will provide dramatic lighting with significant energy savings (you may find you can use a 90watt halogen PAR instead of a 150-watt
conventional PAR).
Halogens also come in non-reflector
models, but you may be better off in
many cases to use a compact fluorescent
which is much more energy efficient.
LIGHTING
Some compacts and components
Replace incandescents
with compact fluorescents
The conventional screw-in incandescent
light bulb not only is extremely inefficient, it also has a very short life and
must be replaced frequently (see Table
6). When you figure the true cost, the
ordinary light bulb is not a bargain!
Clearly, one of the great advances in
lighting technology is the compact fluorescent lamp. Developed as a replacement for the common incandescent light
bulb, the super-energy-efficient compact
fluorescent is just that: a miniature Ushaped fluorescent tube and ballast.
Screw-in compact fluorescents will fit
many of the fixtures where you previously used incandescent light bulbs.
So, without changing the fixture
itself, compacts make it possible to
replace an incandescent (8-24
lumens/watt, 750-2,500 hours life) with
a more efficient and long-lasting fluorescent lamp (50-80 hmens/watt, 7,500
-10,000 hours life). For example, where
you have been using a 60-watt incandescent, YOU can screw in a 15-watt compact fluorescent that will last 10 times
as long-and will deliver the same
amount of light for about one-quarter
the energy! Note, however, that a compact will lose 25-30% of its light output
over its lifetime.
Although compact fluorescents
are considerably more expensive than
incandescents, they will more than pay
for themselves with savings in electricity, lamp replacement and labor costs.
Pay-back is quickest when they are
installed in fixtures that are used for
many hours each day, year round.
Varieties of compacts. Compact
fluorescents are available in a wide variety of styles to suit most lighting needs,
with reflectors and extenders that can
make them fit and work well in a variety
of fixtures.
Compact fluorescents are available
either as one-piece screw-in units that
incorporate the ballast, or as modular
units where the tube can he separated
from the badballast when the lamp
burns out (one-piece compacts must
Upper l e f t one-piece compacts, with and without diffuser
Lower l e f t separate tubes (single tube and
"quad") and screw-in ballast/bases (white one
is offset for lower overall height)
Below: one-piece reflector compacts, without
diffuser and with one.
Table 6
How to save $37 on a light bulb
Comparing total costs over 10,000 hours for
a compact fluorescent and an incandescent
~~
Compact
Incandescent
Watts
Light output
(lumens)
Energy use
Energy cost
20w
75w
1,200
2OOkWh
1,150
750kWh
Q 9$/kWh
Lamp life (hours)
Lamp replacements
Cost of lamp
$18.00
10,000
0
$67 50
1,000
9
0
$6 75
$20.00*
$ ,753
replacement
Original lamp cost
~~
__
TOTAL COST
for 10,000 hrs.
$38.00
$75.00
~-
Total dollars saved 8 9efiWh by using a
compact: $37.00
~~
~~~
Savings** at these kWh rates:
5e
7e
9e
l i e i 3 e 156 17C
we
$15 $26 $37 $48 $59 $70 $81 $92
___
~~
* This is approximate. typical cost for a compact You probably can
get compacts at even lower prices especially when buying in quantity
"Dollars rounded
Savings from labor to change incandescents not included
be discarded, while only the tube need
be replaced in a modular unit).
Most compact fluorescents have lifetimes of 9,000 to 10,000 hours. The ballasts in modular units, available in both
magnetic and more efficient electronic
versions, last 40,000 to 50,000 hours.
Fixtures. Almost any incandescent
fixture type you can imagine is also
available in a compact fluorescent version which incorporates the ballast, with
the tube as a separate replaceable part.
Cold sensitivity. Compact fluorescents can be used outdoors, too, as long
as they are not directly exposed to the
elements. However, they have certain
cold limitations you will want to consider. They are dimmer for a brief time
when they start, until they get up to
their running temperature (an enclosed
light fixture helps) and may not start at
all under very cold conditions. Ask your
supplier which would be the best
lamp/fixture combination for your outside needs, and experiment with the one
recommended before you change over
completely.
Dimming circuits. A compact fluorescent should not be used in dimming
circuit unless equipped with an electronic dimming ballast, now available
for some models.
LIGHTING
Sometimes conventional
incandescents are still
the best choice
Where you have more illumination than
you need but few hours of operation, or
other conditions that would rule out a
compact fluorescent, you may be able
to substitute lower wattage incandescent
lamps. You have a lot of flexibility with
incandescent lamps, since there is a wide
range of lamps with the same size base.
Buy the energy-saving kind.
Always consider the newer energy-saver
incandescents (e.g., 52-watt instead of
60, 90-watt instead of 100).
Use one larger lamp. The higher
the wattage of an incandescent lamp,
the more efficient it is. This means that
where you now use two or more incandescent lamps, try to use one higher
wattage lamp. For example, two 60-watt
incandescents (total 1,780 lumens)
might be replaced with one 100-watt
lamp (1,750 lumens). This will yield
almost as much light while saving the
cost of 20 watts of electricity.
Generally, avoid using
“extended life” lamps. “Extended life”
lamps should be used only where it is
very difficult for you to replace burned
out lamps. They yield less light (lumens)
per watt than regular lamps, and the savings in replacement lamps is completely
offset by their higher energy costs. A better choice for hard to reach areas is the
130v PAR halogens. Their life is about
double, and they are still pretty efficient.
HID-high intensity discharge-lights
are extremely energy efficient and
include mercury vapor, metal halide,
and sodium lights.
If you use dimmers. If you are currently using or considering the use of
dimmer switches, make sure that the
dimmers would really be used. If the
lamp is always kept at a reduced output,
significant energy savings are possible
from installing the most efficient appropriate light source, undimmed. Dimmers,
when dimming, do decrease energy consumption but also lower energy efficiency.
OTHER HIGH-EFFlClE NCY
LIGHTING
Efficient HID lights for
parking, other areas
HID-high intensity discharge-lights
include mercury vapor, metal halide, and
sodium. While mercury vapor is an outdated light source, the other HIDs can be
excellent, long lived and efficient choices.
Sodium. You’re probably seeing more
lights outside that look yellow or yellow-white rather than white or bluewhite. These are the long lasting and
energy efficient sodium lights. The best
sodiums for most uses are the goldenwhite high pressure sodiums (HPS)
which give fairly good color rendition.
Their very high efficiency makes them
an excellent choice for street lights,
parking areas, and perimeter security
lighting. Inside, HPS might be used in a
warehouse or in other areas where preHalogen
reflector
lamps
22
Sodium “wallpack,” a high efficiency
security light
cise color rendition is less important
than in a store or office.
Low pressure sodium is the most energy efficient source available. However, its
monochromatic yellow color (no color rendering) makes it suitable only for certain
roadway, parking, and security uses (e.g.,
an outdoor industrial storage area) where
distinguishing color is not important.
Metal halide lights are the brightwhite ones often seen in gyms and in
overhead lighting in industrial buildings,
and are excellent for those and many
other purposes. Color rendition typically
is good-better than high pressure sodium but not as good as fluorescent.
When switched on, most HID lights
do not light up immediately. In addition, they may not restart (“restrike”)for
up to 15 minutes after being switched
off. If this delay would be inconvenient,
you will want to choose a special metal
halide or HPS lamp and/or fixture that
enables the light to come back on rapidly. Do not use HID lighting as your sole
source for emergency lighting unless it
has immediate restrike capability. Ask
your lighting dealer.
HID lamps require ballasts in order
to work, and the ballasts for the different classes of HID lights are not generally interchangeable. One exception is a
special type of HPS that can replace
some mercury vapor lamps (the bluewhite ones once commonly used in street
lighting), without having to change the
original ballast. However, an HPS lamp in
an HPS fixture makes a more efficient
retrofit. Overall, replacing mercury vapor
fixtures with HPS or metal halide fixtures
is a cost-effective lighting improvement.
LIGHTING
SAFETY AND
SECURITY LIGHTING
Most buildings have lights that are left
ON all the time to satisfy codes or safety
and security needs. While meeting code
requirements, you should be using only
the wattage necessary to do the job.
And although these are often small and
unobtrusive lights and may not be a big
part of your lighting cost, they can be
highly cost effective opportunities to
save some energy dollars.
Retrofit your EXIT signs
EXIT signs are an excellent example of
this type of opportunity. These signs
typically contain two or more small,
incandescent lamps which use a total of
20 to 50 watts and last from 2,000 to
5,000 hours. All exit signs operate 24
hours a day, every day, resulting in
8,760 hours of use in a year. A single
sign may use from 175 to 438 kWh of
electricity per year. In addition, it
requires lamp replacement perhaps four
times a year, an added expense and maintenance burden.
EXIT)
Compact fluorescent replacements
(first illustration under the exit sign) for
these incandescent lamps are available
that operate at 1 2 watts per sign or less,
and last about 10,000 hours for the
lamps and 50,000 hours for the ballasts.
The next lamp shown under the exit
sign uses a series of incandescent lamps
and has about the same energy consumption as the compact, but it has an
estimated lamp life of over 100,000
hours. The bottom LED (light emitting
diode) retrofit is by far the most energy
efficient, consuming about two watts
per sign and lasting an estimated
100,000 hours or more.
Some exit signs also provide some
downlighting through the bottom of the
sign for emergency egress. Be sure that
whatever retrofit is chosen does not
reduce or eliminate this lighting.
Install other new lighting
Lights for hallways, stairways, and
inside parking facilities may also have
excellent potential for energy savings.
Compact fluorescents are excellent for
stairs and hotel hallway lights (but
should be hard wired if thefts might be a
problem), and HPS wall packs can be
used to advantage in parking garages.
NEW CONTROLS
AND REWIRING
Rewiring or installing more efficient
controls can be a very effective investment, with a fast return and “pure
gravy” savings for years afterward. And
some projects cost very little to do.
Consider rewiring
One of the best ways to save on lighting
bills is to turn off some or all lights in
an area when they’re not needed. If your
present switches don’t give you enough
control, you will want to consider
rewiring and installing additional
switches or dimmers.
Your electrician can tell you if
rewiring will be simple and inexpensive or more complicated and costly.
However, even if it seems expensive,
rewiring can be an excellent investment,
23
Rewiring a store for
“half lighting“
Consider a 5,000 square foot store,
where full lighting is used before
and after business hours when staff
clean the store and stock the
shelves, for about two hours a day,
six days a week. Half lighting (SO
every other fixture is on or off)
would be enough, but the wiring
and switches don’t permit it.
The ceiling lights use approximately two watts for each square
foot of store area, or 10,000 watts
(10 kW). So, at full lighting the
store uses 6,240 kWh a year during
these two hours (5,000 sq. ft. x 2
wattslsq. ft. x 2 hourslday x 6
dayslweek x 52 weekslyear 1,000
watt-hourslkwh).
If only half the lights were on,
energy savings would be 3,120
kWhlyear. At 9$ per kWh, this
would save $281 a year. If it were
to cost $500 to rewire and add
switches, payback would take only
about two years! And from then on,
$281 a year would be saved, and
lamps would last somewhat longer.
as the next example shows.
You can use Table 7 , on p. 24, to estimate about how much you would save
each year by rewiring. Simply multiply
the appropriate number of hours in the
table by the number of thousands of
watts of lighting turned off (example: at
9$/kWh, turning off 10,000 watts of
lighting for 10 hourslweek would save
$470 a year-$47 x 10). 1,000 watts
really isn’t very much lighting-six
four-lamp fluorescent ceiling fixtures,
for example.
LIGHTING
Install occupancy sensors
When people are unlikely to remember
to turn lights off, an occupancy sensor is
probably the answer. This is an easy-toinstall motion detecting device that will
turn lights on and off automatically in
an individual space such as a private
office, restroom, or storage area. The
three types of sensors include: ultrasonic, infrared, and ultrasoniclinfrared.
Many sensors cost less than $100,
installed. The dual technology sensor
has the fewest false trippings and greatest range but is the most expensive.
A sensor can be mounted on the wall
just like an ordinary light switch, or
installed in the ceiling or high on a wall.
The sensor turns the lights on when it
senses someone coming into the room or
area, and then turns the lights off some
time after no longer sensing anyone present. Units come either with fixed, preset time delays and sensitivity levels, or
with adjustable ones. You normally
would want to buy a sensor which can be
adjusted for time delay and sensitivity.
You will need to carefully consider
the time delays needed for the area, and
the range, sensitivity, type, and mounting position of the sensor. For example,
ultrasonic sensors may not be the right
choice if occupants of the space sit very
quietly at desks: people in such situations have been known to complain that
they must deliberately move from time
to time to prevent the sensor from dousTable 7
Annual savings from turning
lights off
~~
Your
electricity
cost per
kWh:
5e
7e
9e
lie
13t
15t
176
19e
Your annual savings*for
each 1,000 watts of
lighting turned off for this
many hours/week:
5 hrs 10 hrs
$13
18
23
29
34
39
45
49
$26
36
47
57
68
78
89
99
* Figures rounded to nearest dollar
15hrs
20hrs
$39
55
70
86
101
117
133
149
$52
73
94
114
135
146
177
199
Occupancy sensor can be installed to replace
wall switch. Reverse side of model in center
of photo shows adjustable sensitivity and
time delay controls.
ing the lights. Infrared sensors, on the
other hand, must be placed so that no
obstruction blocks their sensing field.
The more hours the lights are off and
the more watts controlled by the sensor,
the greater the energy savings. Savings
estimates of 20% to 40% are often cited,
and even greater savings are possible
when spaces are used for only limited
times (e.g., a storeroom).
Among the very best places to install
occupancy sensors are: private offices,
conference rooms, dormitory and locker
rooms, restrooms, stockrooms, and hotel
and motel rooms (where not only lights
but HVAC, too, may be controlled to
keep occupants comfortable but save
energy when the room is unoccupied).
Before installing sensors, carefully
evaluate the benefits. Also, not all sensors work well with every type of lighting equipment; be sure the ones you buy
can handle the specific types and
amounts of load you will connect to
them. Look for sensors that have a
“zero-crossing switching” relay feature.
Install timers or
photoelectric controls
for other lights
On page 1 5 you learned about adjusting
timers. If you don’t have such a control,
it can be an excellent investment. For
example, think of the parking lot lights
or other exterior lights you could have
24
automatically turned off and on by a
timer, being assured they were not uselessly and wastefully blazing away during the day or after operating hours.
A “pin” timer is one option, a control
with a photocell is another. Pin timers
must be reset seasonally to adjust for
changes in the length of the day; photocells do this automatically. Another
common configuration uses a combination of a photocell to turn the lights on
and and a timer to turn them off. A
power interruption, such as caused by
an electrical storm, will require that you
re-set the timer. Buying a solid state
timer that is backed up by a rechargeable battery will eliminate this problem
and is strongly recommended.
A timer with a built-in astronomical
clock, that enables it to adjust automatically for seasonal differences between
sunrise and sunset, can be used to control outdoor lighting. It can also be used
to “sweep” indoor areas, turning lights
off and on at set times related to sunrise
and sunset, unless manually overridden.
HID Dimming
For metal halide and high pressure sodium lamps, a two-level step dimming ballast and an occupancy sensor can greatly
speed up the return to full light levels.
Install an EMS
An Energy Management System (EMS)
can control lighting as well as the HVAC
(heating, ventilating, and air conditioning), machines and equipment for one or
more areas or for an entire building.
( S e e p . 67 for more detail.]
Installing a full-fledged EMS for
lighting control alone is not often done.
However, intermediate systems which
are more elaborate than simple timers
but less expensive than an EMS may be
warranted-for example, for different
settings for a restaurant (table set-up,
subdued light for dining, clean-up after
patrons leave).
LIGHTING
Other Possibilities
Install desk lamps and other types of
low wattage “task lights” for “close
work” at desks, drafting tables, product
assembly areas. These provide light
when and where it is needed, can
improve productivity, and may permit
ceiling lighting to be decreased. (Also
s e e p . 19 for computer desks].
A super “task“ light: Delivering the light output of a 60-watt conventional incandescent
right at the work surface, this elegant desk
lamp uses a1 3-watt compact fluorescent.
Use more daylighting, by installing
adjustable window blinds, shades, or
reflective film to admit light when you
want it and yet control excessive daylight,
glare, and heat gain. You may have to
combine this with rewiring and installation of switches to enable you to turn off
those lights that are nearest the windows.
To take best advantage of the natural
light to supplement your artificial lighting, you can install daylight sensing controls that will automatically reduce the
artificial lighting levels when there is sufficient natural light available. An installation of new, dimming electronic ballasts
and the appropriate daylight sensing colitrols can maintain the ideal balance
between artificial lighting and daylight
and maximize your energy dollar swings.
If you are building or renovating, in
“top level” spaces (one-storybuilding,
or a top floor) high-efficiency skylights
are a possibility to explore. Carefully
evaluate such things as heat gain and
loss and the need for supplementary
lighting for night use and dark days.
When you re-paint, use a light color.
Medium and dark colors are poor choices
for large areas if you want to keep your
Putting it all together
This outside private office, which gets
plenty of daylight, previously was
lighted with three fluorescent ceiling
fixtures, each with four 40-watt lamps
and magnetic ballasts. The lights were
left on an average of nine hours a day.
When.a new computer system was
installed, properly oriented to avoid
glare from the window, the office was
redecorated and the lighting redone.
Now the ceiling has two louvered fluorescent fixtures, each with three 32watt T-8 lamps and an electronic ballast. The fixtures can be turned on or
lighting bills down. The higher reflective
ability of a light color may reduce the
number of lamps you need in the area, so
you can remove some lamps or go to lower
wattages. Keep this fact in mind when
you’re going to remodel. The one exception may be illuminated identification
signs: using a dark background with light
colored letters can minimize the wattage
needed to make your name stand out.
Estimating your savings
Use Table 8 on the next page as a format
for calculating all kWh (energy) and kW
(demand) savings. Be sure to include
ballast load when calculating use and
savings; when it is not known, as a rule
of thumb add 10% to the lamp wattage.
To estimate your savings from
relamping, delamping, and disconnecting ballasts, use Tables 9, 10, and 11,
respectively, on the next page.
25
off separately with
individual wall
switches. A sensor
turns off both lights
automatically when
nobody is in the
office, and turns off
the fixture nearest
the window when
there is sufficient
daylight. On average, the fixture nearest the window
is used about five hours a day and
the one nearest the door for seven
hours a day.
The office occupant finds the
lighting easy on her eyes and her productivity increased. Energy costs are
now one-third of what they were
before, and the $500 cost of the lighting retrofit might garner savings of
$50 to $190 a year, depending on the
kWh rate for electricity, while productivity benefits undoubtedly
amount to a much higher figure.
+--
Check
Out Your
Lighting
Take a look a t your present
lighting, using the convenient
”walk-through“ self-audit form
on p.62.
LIGHTING
ighting Savings Tables You Can Use
Table 8
E s t i m a t i n g your
a n n u a l lighting savings
k W h charges saved
Table 9
Save by substituting lower wattage lamps
Your electricity
cost per kWh:
For each change you make,
use this formula
x -
hours per day
--
watt-hours per day
x -
days per year
-
watt-hours per year
1,000
-
kilowatt hours (kWh)
x -
cost per kWh
per year
-
Total annual kWh
charges saved by
making this change
I
Demand charges saved*
For each change that reduces
demand, use this formula:
kilowatts eliminated
x $-
average demand
charge per kW per
month
total demand charge
eliminated
-
9e
11e
13C
15C
176
19e
wh/kWh
-
$ .62
.87
1.12
1.37
1.62
1.87
2.12
2.37
5e
7e
watts
*
Annual electricity savings*
if each replacement lamp saves:
6w
8w
20w
40w
$ .83
1.16
1.50
1.83
2.16
2.50
2.83
3.17
$2.08
2.91
3.74
4.58
5.41
6.24
7.07
7.91
Calculate your savings:
75w
$ 7.80
10.92
14.04
17.16
20.28
23.40
26.52
29.64
$4.16
5.82
7.49
9.15
10.82
12.48
14.15
15.81
Number of lower
wattage lamps
x
$-
Energy dollar
savings for each
(from table at left)
=
$-
Your energy
dollar savings
ner
r
-.
Table 10
Save by removing lamps
Annual electricity savings* for each lamp removed
Your
electricity
costperkwh:
Fluorescent**
40w
75w
llOw
Incandescent
60w
150w
5c
7c
9e
11e
i3e
15C
17C
19t
$4.16
5.82
7.49
9.15
10.82
12.48
14.15
15.81
$11.44
16.02
20.59
25.17
29.74
34.32
38.89
43.47
$6.24
8.74
11.23
13.73
16.22
18.72
21.22
23.72
__
$7.80
10.92
14.04
17.16
20.28
23.40
26.52
29.64
Calculate your savings:
Number of lamps
removed
~~
$15.60
21.84
28.08
34.32
40.56
46.80
53.04
59.28
x
$-
Energy dollar
savings for each
(from table at left)
=
$-
Your energy
dollar savings
per year
Includes electricity but not cost of replacement lamps. Assumes ltghts are used
8 hoursiday, 5 daysiweek, 52 weeksiyear (2,080 hours a year)
* * Additional savings will result if ballast is disconnected, too. See table 11
*
x
-
12
months per year
Total annual demand
charges eliminated
~~~
'Relevant if you are billed for demand-see p 70
Total lighting energy
charges saved
$-
All kWh charges
saved
+ $-
All demand charges
saved
= $-
Total energy charges
saved
A note about savings: Your savings are likely to be from
the lowest rate you pay for electricity (see p 6)
m
ar
,--.
If lights are used 2,080 hoursiyear (8 hoursiday, 5 daysiweek, 52 weeksiyear)
Table 11
Save by disconnecting ballasts
Your
electricity
cost per kWh:
Annual electricity savings* for each ballast
disconnected when fluorescent lamps are removed
6 . 5 ballast
~
* Assumes lights are used 8 hoursiday, 5 daysiweek. 52 weeksiyear (2,080 hours
a year). Also assumes fixtures would be turned on even after lamps have been removed.
26
Number of
ballasts
disconnected
1 2 . 5 ~ballast
$1.30
1.82
2.34
2.86
3.38
3.90
4.42
4.94
$ .68
.95
1.22
1.49
1.76
2.03
2.30
2.57
Calculate your savings:
x
$-
Energy dollar
savings for each
(from table at left)
=
$-
Your energy
dollar savings
per year
our building’s “shell” or “envelope” is made
up of the windows, outside doors, walls, foundation, floor, roof, and perhaps skylights. The
I envelope is the barrier between the carefully
controlled, temperate indoor environment in your
building and the fluctuating and sometimes harsh outdoor
environment. The envelope is also a selective filter which can
be used to make the indoor environment more comfortable, by
allowing certain amounts of light, fresh air, heat, coolness, and
humidity to enter and leave.
If the envelope works well as a barrier and as a filter, you
will use less energy in your lighting and HVAC (heating, ventilating, and air conditioning) systems to control the light, temperature, humidity, and fresh air levels.
Your Objectives
-
Even with a very good envelope, your building will lose heat
in cold weather and gain it when it’s hot outside. Your basic
objective is to minimize these losses and gains. To do this
you will want to:
Stop infiltration. Prevent the leaking in of outside air,
and the leaking out of conditioned inside air, through openings
such as cracks in walls, around windows, and where doors
don’t fit or close properly (but also see important information
on indoor air quality, p . 4 4 ) .
Reduce heat transfer. Minimize the transfer of heat
through materials in the building envelope by conduction and
convection. Heat always flows from a warmer environment to
a colder one. All materials conduct heat, but some, such as
metal or a single pane of window glass, conduct it faster than a
substance like fiberglass insulation, a poor conductor and
therefore a good insulator.
‘‘E” value is a measure of the resistance to heat flow; the
higher the “R” value number, the higher the resistance. There
are various ways you can increase the “R” value of your roof,
walls, floor, and windows, to cut down the transfer of heat
from one side to the other.
Control humidity. Maintain the movement of water vapor
in and out to achieve appropriate humidity levels. For health,
comfort, and protection of materials such as wood, relative
humidity inside should range from 30-60%. Vapor barriers
and ventilation can prevent condensation and associated rot
and mildew problems.
Control sunlight. By letting in the sun’s light and heat
or blocking them out when not wanted, you can reduce artificial light levels, and heating, ventilating, and air conditioning
loads.
Maintenance and
minor changes
28
More substantial changes
Insulation
30
Windows
31
Exterior doors
32
ENVELOPE
Comfort vs.
cost effectiveness
From the experience of the past 10 to 20
years, it has become clear that weatherizing building envelopes is not always
cost effective in terms of energy savings.
The most cost effective programs have
relied on building diagnoses supported
by pressurization testing before any investment was made. But this sort of
analysis may not be possible or sensible
for you.
However, this should not stop you
from considering tackling the biggest
and most obvious deficiencies or pushing the building owner to do it-e.g.,
adding insulation so your HVAC doesn’t
have to run continuously, replacing
glass in windows, fixing doors that
won’t close, etc. It does mean you
shouldn’t go around trying to seal up
every little crack to make the envelope
tight as a drum; there are probably better
places to put your time and money.
Also, even if not cost-effective in
terms of energy savings, some of your
weatherization efforts will make the
interior space more comfortable for people, producing productivity gains and
other benefits.
If you rent
If you rent space on the top floor under
a poorly insulated roof, you probably
dread the hot weather. Even if you are a
tenant of space on a middle floor, there
is a part of the envelope-principally
the windows -that directly affects both
your energy costs and your comfort.
How well the rest of the building envelope works can also affect your energy
costs and comfort.
If your landlord won’t make the necessary changes, your HVAC or lighting
energy savings may be high enough to
justify making the investment yourself.
Maintenance and Minor Changes
piece of tissue paper held at one end is
also useful for locating drafts. Make sure
you check any attic or crawl spaces,
utility rooms, and the roof, identifying
each suspicious location.
I
--
Seal cracks with caulking
or other materials
Air-leaking cracks may be present for
several reasons: the building was not
tightly constructed in the first place;
cracks developed as the building aged;
or the original sealing material has
dried out and pulled away.
Inspect the outside to locate cracks
and other obvious openings. On the
inside, look for cracks of daylight and
feel for drafts. Ask occupants where
they notice drafts on a windy day; a
Smaller places that may need sealing:
around window and door frames
where the walls meet the foundation
in the foundation itself
where walls join at corners
around window air conditioners and
other equipment installed in walls or
the roof
around places where piping, electrical conduits, or telephone lines enter
the building or penetrate walls or ceilings
between heated and unheated spaces
around the chimney (flue chase) of a
furnace or boiler
Start with the largest and easiest-tofix openings first. You will probably
need a variety of sealing materials.
Install caulking where there is none,
and remove and replace worn-out
caulking. Use the highest quality caulking materials; acrylics are easy to use
28
and very long lived. Follow the manufacturers’ directions (some caulks
require temperatures above 40°F, all
require that surfaces be cleaned first),
and use the “push method” shown in the
illustration.
Fill large cracks with foam “stuffers”
or glass fiber insulation before caulking
them. Some masonry cracks will require
cement rather than caulking. Use sheet
metal to close the opening around a flue
chase. For outlet boxes, use pre-cut
foam insulating pads; for large irregular
holes, use expanding foam.
Note that in multi-story commercial,
industrial, and multi-family buildings
fire stopping is required for all vertical
penetrations. Be certain that what you
do is in accordance with code.
ENVELOPE
Tighten up window
and door frames;
repair, replace, or install
weatherstripping
Tighten up window and door frames
with screws, and make sure they have
weatherstripping, especially between
the upper and lower sashes of doublehung windows and around all exterior
doors. Pay special attention to the
“weather side” of your building, where
winds usually come from during cold or
hot weather.
If existing weatherstripping is in
good condition but has come loose,
refasten it with an adhesive, nails,
screws, or staples, whichever is appropriate. If it has deteriorated or there is
none, install the type that is designed
for the particular purpose. There is a
special kind for double doors, which
often are hung with a substantial gap
where they meet so they can swing
freely. For the bottom of a door you
should use something called a “door
sweep.”
For economy, doors and windows
that do not move should be caulked
rather than weatherstripped.
Replace broken glass
Broken or cracked windows are not only
hazardous, they also leak warm or cool
air and drive up your energy bills.
Missing panes do, too. Check your windows, and make the necessary replacements. If you need to patch a cracked
window temporarily, there are heavy
transparent tapes (not ordinary officetype adhesive tapes) that can be used for
this purpose.
Fix doors and windows
to operate properly
Fix exterior doors and windows that
don’t fit tightly or close completely;
don’t forget back doors and loading
dock doors. Do the same for any interior
doors that separate areas with different
temperatures-a door to an unheated
storage area, for instance. Some doors
may need to be completely re-fitted or
re-hung; in other cases, simply adjusting
the striker plate or planing off an eighth
of an inch will do.
Adjust, replace, or install
automatic door closers
Outside doors frequently have automatic door closers to ensure that they close
completely all the time. Adjust all
closers, by turning the adjustment
screws, so they operate properly and
close the door rapidly enough; slow
closing lets cool or warm air escape or
enter. If the closer is worn out or missing, and the door is on the weather side
or is one which people are forgetful
about closing behind them, install a new
closer and adjust it properly.
Cover window air
conditioners in cold
weather
exterior doors with no weatherstripping
can easily have an opening of 1/4”where the
doors meet. While this doesn’t look or sound like
much, on a 6’8“ high pair of doors it adds u p
to the equivalent of a 20 square inch opening
(the size of this circle)!A similar gap in just
two average-size double-hung windows,
where the sashes meet, would add u p
to the same 20 sauare inch hole!
29
In addition to making sure there is
caulking around the window opening
for a window air conditioner, cover the
exterior portion of the unit during cold
weather. If left uncovered, even with
vents closed, these units can let in
cold air.
ENVELOPE
More Substantial Modifications
INSULATION
Add building insulation
Adding insulation can increase your
building’s resistance to heat loss and
gain, and may be the most important
building envelope improvement to make.
Depending on the shape of the building, it may be more economic to insulate
the roof than the walls. This obviously
will be the case for one-story buildings,
where the roof area is a high percentage
of the total area of the building envelope. For tall buildings, roof insulation
is less important.
If your building is both heated and
air conditioned, insulation works yearround -in winter it reduces your heating bill, in summer it cuts your air conditioning bill.
Roof insulation may he installed
inside in the space under the roof, or
outside between the structural roof
members and the weatherproofing material. “Batts” or rolls or blown-in insulation are used inside, foam boards outside.
Wall insulation for an existing wall is
usually blown in between studs or
applied inside (in hatts or boards) and
then recovered with some interior wall
surfacing material such as sheet-rock.
Different insulating materials have
different properties and “R” values. It is
often recommended that roof insulation
bring resistance up to R30, wall insulation to R19. State or local building codes
often specify minimum acceptable R
levels for new or renovated buildings.
Here are several important considerations to bear in mind:
Prevention of moisture build-up.
Vapor barriers and adequate ventilation
are important to prevent mildew and rot
of building materials. But he careful not
to add vapor harriers to existing ones;
this will cause condensation in the insulation or structure.
Roof load in cold climates. With
adequate roof insulation, snow will melt
much more slowly. Make sure your roof
is strong enough to support the added
weight of snow accumulations.
ln buildings with high internal
heating loads such as those caused by
large computers or incandescent flood
lighting, added insulation may increase
the air conditioning costs, but this can
be partially offset hy reduced heating
costs. In such a case, be sure that “optimal” insulation values are determined,
taking into account both the internal heat
load and year-round climate conditions.
Code requirements. Insulation
must meet state or local code requirements for fire resistance and perhaps
other properties.
Adding insulation can lead to significant reductions in energy bills, particu-
30
larly if there is currently no roof insulation at all, but it isn’t necessarily a good
bet in every building. To make sure you
make the right decision, get the help of
a reliable firm before YOU invest, to
inspect your building and give you estimates of both costs and savings.
Table 12
R Value of
Some Insulation Materials
~~
Material
R Value
per inch
of thickness*
Fiberglass loose fill
Mineral fiber 100%
Mineral fiber blanket
Cellular glass board
Perlite board
Fiberglass batt
Cellulose loose fill
Mineral fiber board
2.5-3 .O
2.5-3 .O
2.5-3.5
2.8
2.8
3.0-4.0
3.1-3.7
3.5
Polystyrene molded bead board
Fibrous glass board
Polystyrene foam board
Polystyrene extruded
Polyurethane foam board
3.6
4.0
4.2
5.0
6.3
Polyurethane foamed in place
Polyisocyanurate foamboard
Phenolic foam board
~~~~.
-. . . -
6.7
7.2
8.3
* The R values here are representative. Insulating products are
labeled for actual R value.
ENVELOPE
WINDOWS
Insulate and
shield windows better
Single pane window glass conducts a
great deal of heat; its thermal resistance
(R value) is very low, only 0.9. Single
pane “storm” windows that fit over
existing windows, and multi-layer
“thermal” replacement windows (see
below) can raise the R value considerably
and resist the passage of a lot of heat.
You may want to consider storm
windows if your present windows are in
good condition and you are interested in
maximum transmission of light. If you
do not open your windows, large glass
storms or single sheet plastic interior
storm windows that remain in place
year-round may be a good choice. Plastic
exterior windows will also resist breakage. If you have double hung windows
that you do open, double hung “triple
track” storms with Screens may be best.
If an area is uncomfortable because
of overheating or glare from too much
sunlight, you should consider having
reflective or “solar” film applied on
the inside of the windows. Some films
protect against both glare and overheating, while others reduce heat gain in the
cooling season and prevent heat loss in
the heating season. Ask for some expert
advice before making your selection.
Install new windows
If you are remodeling and planning to
replace your existing windows, you will
find that advanced window technology
gives you a number of exciting energy
saving options. Most manufacturers
offer a double pane “low E” (low emissivity) window as their standard product, with insulation values approximating that of a triple pane window but at
lower cost. Advanced performance windows are available with R values of two
to eight, many times higher than older
standard units. In addition, windows
are available which tune your building
to the local climate by emphasizing
reduction of solar gains in cooling climates or minimizing heat loss in heating
climates.
-
On a high school converted to an office building, lattices provide horizontal design accent
and shield windows from sun‘s heat.
On an office buildins. reflective film applied
..
to existing windows blocks sun‘s rays.
Don’t ignore the conductivity of the
window frame and mullions. Look for
National Fenestration Association ratings which rate the entire window and
not just the center of the glass.
Block up unneeded
Consider other
window treatments
Since windows not only are the most
heat conductive parts of the building
envelope but also greatly affect the comfort of people inside, particularly in
warm climates you may want to consider these other ways to shield windows
and reduce heat gain in hot weather:
Movable awnings.
Fixed lattice grilles and “brise soleils”
(recessed windows to consider if you
are building a new structure) that,
without any moving parts, block
sunlight at certain times of day.
Deciduous shade trees on the east,
west, and south sides of your
building, particularly a low building.
windows and
other openings
Unless a window provides light or air, it
may not be needed. Because of construction costs, however, it probably will not
pay in terms of energy savings to block
up a window opening. But there may be
other reasons, such as a remodeling plan
or security needs, which call for eliminating some windows.
An alternative to “walling up” is to
use a preformed insulated wall panel or
a sheet of insulating material on the
inside, such as polystyrene or polyurethane foam board, if interior and exterior aesthetics permit. To be effective, the
material must be carefully cut and fitted
to fully close the opening. If there is a
choice of windows to seal up, select
those on the windy “weather” side of
your building.
Double pane “low emissivity” window (at left) keeps out heat in hot weather, keeps in heat in cold
weather; clear glass window (right) lets most of the heat through. ltiustratlon concept courtesy Southern californla Edlson
31
ENVELOPE
EXTERIOR DOORS
Auto service area doorshow to keep them closed
These large doors may be opened to let
vehicles or people pass, or for ventilation, resulting in substantial heat loss or
gain. First, as much as possible keep
interior doors closed that separate the
service area from the rest of the heated or
cooled part of the building. Then, in the
service area itself, consider the following:
Installing an automatic “electric eye”
door opener/closer that keeps the door
open only when a vehicle is passing.
Cutting a small, person-size door in
the overhead door (many auto service
facilities have these).
Installing an exhaust fan system with
hose connections to tailpipes to
remove exhaust fumes without displacing the heated or cooled air in
the service area.
Wiring heaters or air conditioners in
the service area to turn off whenever
the overhead doors open.
Installing radiant heat that heats
materials and people but not the air.
If the overhead doors don’t fit well
around the sides and bottom, install
flexible moldings and weatherstripping designed for this purpose or,
along the bottom, try using rubber
strips cut from an old inner tube. Be
sure, however, that there will still be
adequate ventilation once these
openings are closed.
.
In addition to achieving energy savings,
the more comfortable the auto service
area the more productive the people
working there are likely to be.
Vestibules and
vestibule doors
A vestibule with two sets of doors acts
as an airlock to reduce the amount of air
that can enter or escape from your
building as people enter and leave. You
may be able to create a vestibule by
installing a door or set of doors inside
your building, or you may have to build
it on as an addition. A vestibule does
not necessarily have to be heated or air
conditioned (see HVAC section).
If you are remodeling or constructing
a new building that gets lots of “people
traffic,” consider installing a revolving
door. This can greatly reduce infiltration
and increase comfort in lobbies, particularly in windy locations.
If your loading dock is exposed to harsh
winds, it is more likely you will want to
install the flexible windbreaks. Besides
energy savings, another advantage is that
the workers will be protected from the
weather and the job may get done faster.
Curtain of plastic strips made by wholesale
company’s owners is used year-round, prevents both heat loss and gain while permitting
access to loading dock.
Flexible wind breaks
and interior doors for
loading areas
At a loading dock there is a very large
wall opening, perhaps measuring 100
square feet. You will want to consider
the following, both for energy savings
and for comfort and productivity of
workers:
Making the opening smaller, if it is
larger than needed.
Making sure trucks back up straight
and as close to the opening as possible,
so the least amount of heated or cooled
air will escape or enter the building.
Installing a curtain of plastic strips or
a flexible windbreak (dock seal) all
around each opening.
When the exterior door is open, being
sure to close the doors that separate the
inside of the loading area from the interior of the building. If there are no such
doors, you may want to install some.
Check
Out Your
Envelope
Take a look at your building envelope,
using the convenient “walk-through”
self-audit form on p.63.
Keeping overhead doors closed as much as
possible reduces heat loss and gain.
32
H
eating, Ventilating, and Air Conditioning
(HVAC)-may be the biggest user of energy
in your building. Fortunately, it’s possible t
save 30% or even more on your HVAC energy
bills. To trim those bills, most things you can do fall
into one of these categories:
Turn it off when not needed.
Run it less (including more efficient temperature settings).
Make it more efficient.
The first two you can usually do yourself, the last probably
will require some assistance from qualified professionals-your
electric or gas utility, HVAC sales and service firm, or an energy
conservation consultant. These people may best be able to help
you correct the inefficiencies which can occur in many places
in these often complicated systems. They can also help you
evaluate energy efficiency investments. Review this section of
the book with your expert, and get him or her to identify and
explain the energy saving opportunities you have in your particular HVAC system. Not everything here applies, or will yield
enough in energy savings to make it worthwhile to do.
What type of HVAC
system do you have?
The purpose of an HVAC system is to provide filtered fresh air,
heating, cooling, and humidity control. There are many different kinds of HVAC systems, often consisting of both heating and
cooling equipment. Some systems may also dehumidify in summer or add humidity in winter.
Heating and cooling sources. The heat source may be a
central gas- or oil-fired boiler or furnace,
electric resistance heating units, or a
heat pump. Cooling is usually provided
by an electric chiller, air conditioner, or
operating
your
heat pump (some systems have a steam
and/or gas-fired absorption chiller or a
HVAC efficiently
gas engine-driven chiller).
Types of air conditioners. There are three basic types of
air conditioners: direct expansion, chilled water, and evaporative or “swamp” coolers (the last is usually appropriate only in
dry, hot climates). In direct expansion units, air is cooled and
dehumidified as it moves past a cold coil filled with refrigerant. Window air conditioners, “packaged” or roof-top units,
and heat pumps are direct expansion type coolers. In chilled
water systems, water instead of air is cooled by a central unit.
In chilled water systems, water is cooled by a refrigeration
machine; the cool water then supplies a coil which cools and
dehumidifies the air. In evaporative coolers, the hot air is
brought into contact with a damp surface or water spray, and
the resulting evaporation of moisture in the airstream lowers
its temperature (“indirect” units have a heat exchanger).
Distribution. The heat and cooling may come directly to
a space from the unit itself (e.g., a window air conditioner) or
be distributed throughout a building using air ducts, water or
steam pipes. Radiators or baseboard units may deliver heat to
your space in water, steam, or electric resistance systems. In
forced air systems, blowers and registers can deliver the heat
andlor cooling.
Simpler maintenance jobs
34
37
Adjustments and maintenance
jobs for an expert
38
Upgrading your
HVAC system
40
HVAC buying guide
41
Possible investment projects
42
HVAC
Operating Your HVAC Efficiently
I
efficiently.
ally, say lo lower every week, so people
have time to adjust-and check to see if
they are comfortable. Customers, clients,
or other visitors may not notice the
change at all.
Experiment to see how low a setting
is still comfortable. If there are areas
where people feel cold, repair any outside air leaks or add needed insulation.
Your heating system may need to be balanced (see below) so that the heating
ducts or radiators in the uncomfortable
area can deliver the required heat.
Table 13
Reducing Heating Temperature
When Building is Occupied
Heating
Degree
Days'
Energy savings**
if thermostat setting
is reduced by:
1,000
2,000
3,000
4,000
5,000
6,000
7,000
3"
5"
7"
15%
14
13
12
I1
26%
24
22
20
18
36%
33
31
28
25
10
9
16
14
13
11
9
23
20
la
15
12
8,000
a
9,000
6
5
10,000
'
If balancing doesn't work, you may want
to use some supplementary heat sources
to provide the needed warmth.
For cooling,
set thermostats higher
Research indicates that energy savings
are even greater, per degree, for raising
air conditioner thermostat settings than
for reducing heating levels. As with
changes in your heating system thermostats, make the temperature change
gradually, say 1" higher every week, so
people have time to adjust-and check
to see if they are comfortable. Visitors
coming in from the warm out-of-doors
will still feel a welcome contrast. even
though the indoor temperature is somewhat higher than it used to be.
Once aeain.
exDeriment to see how
"
high the settings can be without causing
undue discomfort. Particularly if the
people who occupy your space are relatively inactive, perhaps sitting at desks
or standing behind counters most of the
time, considerable changes in the settings may even be welcome-recall the
times you have seen someone in a super-
* Seep.32.
*' If temperature is reduced tor entire time heating system is
in operation.
~~
~~
Source: "Reducing Energy Costs Means a Better Bottom Line,
National Frozen Food Assn./U. S Dept of Energy
34
If you have an older thermostat,
installing a programmable control can be an excellent invest-
cooled office typing with a sweater on.
If an area is too warm for comfort at
the new setting, check for air leaks, poor
insulation, or sun which can be blocked
with shades, blinds, or window film. If
an area is too cold, adjusting the register
can reduce the air flow; otherwise, the
thermostat setting may need to be
raised. If neither of these works, call
your HVAC technician.
When you raise the thermostat settings, make sure there is a good supply
of air from your HVAC registers (the fan
speeds may need to be increased). First,
it keeps temperatures even and prevents
cool air from collecting in a layer near
the floor; second, it promotes the cooling process of evaporation of moisture
from the skin; and third, it supplies
fresh air to counter drowsiness which
could occur from a combination of
somewhat higher temperatures and stale
air. And remember, running a fan is considerably cheaper than running an air
conditioner. On nice days, open some
windows if you can, instead of mechanically cooling the air.
HVAC
Eliminate unnecessary
use of your HVAC system
during unoccupied hours
You may be using energy to heat, cool,
or freshen the air when nobody is there
to benefit-at night or on weekends, for
example. If occupancy hours are different for various parts of your building or
area, you can control temperatures for
each area individually only if there are
separate heating or cooling units, zones,
or thermostats (see below). But it may
well be that your entire operation works
on a regular 8, 10, or 16 hour basis.
Your present temperature controls
can be operated manually by a person
who has been given the responsibility
for seeing that it is done every day. If
you feel this may not be a reliable
method, you can have a programmable
thermostat or seven-day timer installed
that will turn the system, or some part
of it, on and off automatically. You may
already have such a device. If so, make
sure it is set properly.
Energy is used to run the circulating
fans and pumps, so the ventilation sys-
tem should be shut down when the
building will be unoccupied-unless
health code provisions require round the
clock ventilation. Savings can be substantial. For heating, for instance, a 14hour night setback and full weekend setback, from 65°F to 50°F in a 5,000 heating degree day area, would result in
energy savings of 28%! 'lise the heating
degree day map and Table 15 to see what
your savings would be. Contrary to what
you may have heard, it does save energy
dollars to turn off the HVAC system and
let a building cool down or heat up during off-hours, and then restore it to the
desired temperature some time later.
An important note about heat
pumps. If you have a heat pump with
supplementary electric resistance heating elements, be sure the recovery from
the heating setback is done gradually so
the heat pump can bring your space
back up to temperature without using its
heating elements. Your heat pump may
already incorporate a "step-up" thermostat
which will do this;if not, one can be added.
Table 14
Approximate Percent Savings
from Heating Setback During
Unoccupied Hours
Degree Days
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
10,000
Setback Temperature
60"
55"
50"
13%
12
11
10
9
8
7
7
6
5
25%
24
22
20
19
16
15
13
11
9
38%
36
33
30
28
24
22
19
16
14
NOTE: Based on 65°F temperature and 14 hour night setback.
Assumes lull weekend setback.
Source: "Reducing Energy Costs Means a Better Bottom Line,"
National Frozen Food Assn./U.S. Dept. of Energy
Degree Days
Normal Number
of Heating Degree
Days Per Year
What is a Degree Day?
A heating degree day is defined as the difference between 65'F and the average of the high
and low temperatures in a given day. The
higher the number, the more energy will be
used in heating your building.
Example: On a given dayHigh Temperature:
Low Temperature:
Average Temperature:
50°F
20°F
50°F t 20°F = 3 5 0 ~
2
65°F - 35°F = 30°F
Therefore, the particular day was
a 30-degree-day day.
Although the heating degree day reading is useful, keep in mind that
other factors such as sun load or excessive infiltration due to high wind also
affect the heating requirements of a building and are not taken into account
by the degree day calculation. The calculation also does not reflect how
long the temperature remained at its high or low.
The accumulation of degree days in a given month and year to date
should be available from your local weather bureau or utility, or you can use
the map above to make a rough calculation.
35
HVAC
/
I
Turn your HVAC off earlier
Turning your HVAC system down, or
off, when your building is unoccupied,
will save you energy dollars. For even
greater savings, lengthen this time period.
At the end of the day or evening, ,
adjust the thermostat settings a halfhour before occupants leave. Your building will stay relatively warm or cool for
some time after the HVAC is turned off or
the settings are changed for the night.
A little experimenting will help you
determine how long your space will stay
comfortable after the HVAC system is
turned off. Times will vary by the season; don’t forget to change your timer or
programmable thermostat settings
accordingly.
Use window coverings
to advantage
In the heating season, closing curtains,
shades, and blinds at night and during
unoccupied periods will help retain heat;
keeping them open on sunny days can
provide you with some free solar heat.
In hot weather, wise use of window
coverings can prevent some heat gain.
External coverings such as awnings are
more beneficial than internal ones.
Draw in naturally cool
outside air
Eliminate HVAC system
use in vestibules
During certain moderate periods of the
cooling season, you may be able to open
windows to let out warm air and admit
cooler outside air. There may be many
times when this very old fashioned
method will work quite well for you.
At night, you may be able to precool
your building for the next day. If this
seems like a good technique for your
building and your climate is dry, you
may want to consider operating or even
installing a large attic-type exhaust fan
and opening vents or windows on the
opposite side of the building to speed
the process of “flushing” the day’s accumulated warmth from the building.
If you have distributed air conditioning from a central unit with an “air side”
economizer mode, make sure the economizer is functioning properly, shutting off
the mechanical refrigeration unit and
allowing the fan to bring in cool outside air.
Buildings sometimes have heating or
air conditioning in the vestibule areas
between the street doors and inner front
doors, but most of the benefits are lost
as soon as the outer doors are opened.
To save energy, see if you can turn the
heating and cooling supply to the vestibule off entirely. The airlock effect of
the vestibule itself probably will prevent
cold or hot blasts from blowing in. Ask
people near these doors whether they
are uncomfortable (receptionists or
check-out people, for instance). If they
are, it may be more economical to buy
inexpensive individual heaters or fans
that they can turn on when necessary.
If your building’s orientation or a
severe climate still requires some heating or cooling in the vestibule, you may
at least be able to reduce its level and
achieve some energy savings.
Use exhaust fans
as little as possible
Exhaust fans in restrooms sometimes
operate continuously. If codes permit,
rewire so that fans operate only when
lights are switched on. This will save
electricity used to power the fans and
will prevent excess loss of interior air
that you have paid to heat or cool with
your HVAC system. Even if fans and
lights are best left on when the building
is occupied, you will at least be able to
achieve savings during unoccupied
hours. It may make sense to install occupancy sensors (see p . 21) to control the
fan and lights.
Kitchen and work area exhaust fans
should also be turned off when the areas
they serve are unoccupied. However, an
occupancy sensor may not be a good
choice for doing this, as exhaust fans may
be needed during operating hours even
when nobody is actually in the space.
36
HVAC
Simpler Maintenance Jobs
Inspect duct work, repair
leaks large and small
Check your thermostats
Make sure your thermostats give true
readings. Obviously, if a thermostat setting of 78" is cooling the air to a real
temperature of 75", your HVAC system
is running more than is necessary and
is costing you a lot of energy dollars.
Use a thermometer you know to be
accurate-buy a good one, if necessary
-and check each of your thermostats.
First, run your HVAC system until a stable temperature is reached. Then measure the real temperature with your
accurate thermometer; take the reading
right next to the thermostat.
If you are unable to adjust ("Calibrate") the thermostat yourself, get a
technician to do it. In the meantime,
make a note of the deviation so you can
set the thermostat differently to achieve
the actual temperature you want (in this
case the deviation is 3", and you would
set it at 81' to get a true 78").
Most older thermostats must be level
to work properly.
Lock your thermostats
if necessary
Being able to control thermostat settings
is crucial if you are going to save energy
dollars. While many HVAC controls are
hidden from view inboiler or mechani-
tal rooms, thermostats are frequently
located where people can see them. If
not protected in some way, settings can
easily be changed by anybody. If your
experience has been that employees,
clients, or customers tamper with the
settings, first talk to people to see if
there are any real problems with the settings you have chosen. They may be too
high or too low for people's comfort, at
least in some areas. If the settings seem
reasonable but the tampering still
occurs, consider spending the few dollars needed to buy and install a locking
enclosure. If you now have such enclosures, make sure they work and cannot
be tampered with.
Replace air filters regularly
A simple and very inexpensive maintenance iob in air conditionine and warm
air heating systems is to replace dirty
air filters (most are disposable, although
some may be cleaned with water). They
not only keep the air fresh, but more
importantly they make it easier for the
system to work, keeping its performance
level high and saving energy dollars.
(although energy use by the fans often
increases slightly in systems where the
fans run on independently of heating or
cooling load).
Clean filters also keep dirt and dust
off of diffusers and coils and out of fans
and motors, prolonging their useful life.
If your filters are dirty or missing, the
blower and coils may need cleaning, too.
This should be done by a technician.
v
Locking thermostat enclosure prevents
unwanted changes in settings.
37
If you have a forced air system, make
sure the ducts are delivering all the heat
and cooling to where they're needed.
Major leaks in duct work are quite common, both in air supply and return systems. These, along with numerous small
leaks due to poor seals between duct
work sections, are often responsible for
occupant complaints and system inefficiencies.
Carefully inspect your air duct system including ducts in crawl spaces and
attics. Major breaks should be repaired
and joints sealed with an appropriate
duct sealant, before you tackle any other
system performance problems (Le. system balancing, control settings, etc.).
Insulation that is hanging loose from
ducts should be refastened.
Making sure duct joints are not open
can help reduce mold build-up in ducts,
in unheated areas such as basements
(especially moist ones). It can also
reduce radon distribution to other parts
of the building; however, if you have a
radon problem, make sure you fully
address it-don't just close up duct joints.
HVAC
Adjust air duct registers
A forced air system has registers or diffusers which let cooled air or heated air
into your space. These registers frequently can be adjusted by moving
something-a lever, chain, slotted
screw, or the louvers themselves. The
air flow may also be controlled by a
Close
Air
Conditioning
Heating
damper in the duct. If an area is too hot
or too cold, making the adjustments can
often cure the problem.
When the heat or the air conditioning
is on, see if you can open or close the
registers so each space is comfortable.
Generally, registers farther from the circulating fan or main heating or cooling
unit should be more fully open than
those nearer the source of heat or cold.
Balancing the system in this way may
enable you to adjust your thermostats to
more economical settings. Contact a
professional to balance your system.
Close
Adjustments/Maintenance Jobs for Experts
Many HVAC systems are quite complex,
others merely somewhat baffling to people who are unfamiliar with this type of
ecluiument. The following are some
energy-efficiency adjustments which
may require little or no capital investment but which should be undertaken
by an HVAC technician who is familiar
with the kind of system you have. Also
listed are some important maintenance
tasks that probably should be done by a
professional.
I
I
Y
COOLING SYSTEM
MAINTENANCE
Have your air conditioner,
heat pump, chiller
properly maintained
Whether you have an air conditioner,
heat pump, or chiller, proper maintenance and adjustments will make your
cooling system more efficient.
Except for changing filters, which
you may be able to do yourself, have
these jobs done by an HVAC technician.
Cleaning. Heat pumps, air conditioners, and chillers all work by transferring heat. The heat transfer surfacesheat exchangers, evaporator or condenser
coils-must be clean and cleared of any
obstructions in order to assure high operating efficiencies. In an air condition-
Refrigerants
and the Environment
Until the end of 1995, when an
international accord ended their
manufacture, chlorofluorocarbons
(CFCs)were the most often used
refrigerants. It is likely that your
refrigerator or cooling system now
contains CFCs.
CFCs destroy ozone when
released into the atmosphere.
Venting CFCs into the atmosphere is
now illegal and there are large fines
for doing it, so your technician will
be careful when servicing your system. Ask the technician about a
non-CFC replacement as an alternative to cleaning and replenishment.
If you are disposing of a system
yourself, you are responsible for
safe disposal or recycling of the
CFCs: ask how to do this in your
community.
When buying new equipment,
look for non-CFC refrigeration systems (there may be CFC units on the
market for some time that were
already “in the pipeline” at the end
of 1995).
38
ing system, the outdoor or condenser
coils are most subject to dirt accumulations and will need frequent cleaning.
Adjustments. Making an adjustment that raises the temperature of the
cold air supply from your air conditioner or heat pump or the cold water supplied by your chiller, even by just 2” or
3”F, can produce energy savings of
3 - 5 7 0 . If you have a heat pump, it may
have supplementary electric resistance
heating elements that “kick in” when
needed. If there is an adjustable control
for their operation, have your technician
set it to assure that this heat is on only
when the heat pump needs the assist (e.g,
when outside temperatures are low).
Refrigerant. All air conditioners,
heat pumps, and chillers (except
“swamp coolers”) have a sealed subsystem that contains or is “charged” with
refrigerant. Have a qualified technician
test for and repair any leaks in the
equipment and refrigerant lines and
then verify that the refrigerant charge in
the system is correct. This is not simply
a case of “filling the system up,” since
over- and under-charging will be detrimental to the energy efficiency and
operating life of your system. The technician must refer to refrigerant test
charts for your specific make and model
of equipment.
HVAC
FUEL-FIRED HEAT1NG
SYSTEM MAINTENANCE
Recent evaluations of efficiency programs across the country pinpoint the
most cost-effective adjustments and
maintenance actions that will correct the
most common problems with gas or oil
heating systems. These few steps will often
save at least 5-10% in fuel and, fortunately,
tend to be quite inexpensive to do.
Have someone test,
clean, and adjust your boiler or furnace
Making sure your fuel-fired heating
plant is working efficiently is one of the
best and easiest ways to save energy dollars. One major problem is inefficient
combustion of the gas or oil, which
wastes fuel and frequently causes air
pollution as well. Testing and tuning
your heating plant may cost less than
$100 but can save you many hundreds
and even thousands of dollars in a single heating season.
f
ciency after adjustment should be a few
percentage points higher than the AFUE
efficiency rating shown on the label (see
p . 42). If the label is missing, your technician may be able to tell you what the
manufacturer’s AFUE rating is for the unit.
A gas burner should be checked and
adjusted at least every other year, before
the heating season starts. An oil burner
should be tested and serviced before the
beginning of every heating season to make
sure that nozzles aren’t clogged or worn,
dampers are operating as they should, and
the burner is adjusted properly. Some
kinds of oil burners must be serviced
more frequently. A rotary cup burner, for
instance, should be tested monthly.
When your heating plant is tested and
adjusted, any accumulated soot should
be removed from boiler tubes and heat
transfer surfaces. Soot deposits act as insulators, prevent efficient heat transfer,
and require that more fuel be burned to
yield the same amount of heat.
Have your technician show you the
test results and tell you what else may
be needed to make the unit perform
properly. Substantial improvements in
efficiency may not be possible because
the basic design of the burner is obsolete. If the technician tests your present
burner and finds this to be true, you
may want to consider installing a modern fuel-efficient burner that will repay
its cost in fuel savings in a relatively
short time. If the boiler or furnace itself
is inefficient, be sure to select an energy-efficient replacement or a heat pump.
Have your technician check combustion efficiency by measuring carbon
dioxide (CO,) and oxygen (02)
concentrations and the temperature of stack
gases and then make the appropriate
adjustments. This will increase the efficiency of your system and help
reduce fuel costs.
If your boiler or furnace has a yellow
and black EnergyGuide label, the effi-
39
CONTROL SETTINGS
Have the technician
select the best heating and
cooling system
control settings
When you adjust a thermostat in your
building, you determine whether the
heating or cooling system is ON or OFF,
at least for that space or zone. The system itself, however, has other controls,
not accessible to you, that are important
for its efficient operation.
When these system controls are set
by a knowledgeable technician, worthwhile energy savings can result. Have
your technician check to see if:
the hot air or hot water supply
temperature can be lowered;
the forced air fan or water circulation
pump remains ON long enough after
the heating unit, air conditioner, or
chiller turns off, so that the heat or
the cool air still in the distribution
ducts or pipes is delivered to the
area where it is needed.
Often the system controls can be modified to boost system energy efficiency
(see p.42 for some possible modifications).
OTHER HVAC
ADJUSTMENTS AND
MAINTENANCE JOBS
FOR A N EXPERT
Reduce fan speeds, adjust belt drives.
Check valves, dampers, linkages, motors.
Repair, recalibrate, or replace controls.
Turn off water pumps in hot water
heating systems in mild weather.
Check and maintain steam traps,
vacuum systems, and vents in onepipe steam systems.
HVAC
Upgrading Your HVAC System
There are several types of opportunities
to improve the efficiency of your HVAC
system by installing new components:
when you must replace a component;
when you choose to make a modest
change in the system;
when you decide to replace the system
or make a substantial modification.
When you have to
redace somethina:
a unique opportunity
I
-
An HVAC failure is always something
that has to be dealt with quickly. But
don't throw away what may be your best
chance to upgrade your HVAC system,
improve its efficiency, and lower your
energy costs.
Whenever part of your system needs
to be replaced-a fan, circulator pump,
compressor, boiler, furnace, chiller, or
other piece of equipment-don't automatically buy an exact replacement.
There may be a different replacement
that will be your best buy.
The first step is to engage an engineer, independent of any equipment
vendor, to carefully develop an estimate
of your heating, cooling, and ventilation
loads. This analysis will tell you the
capacity or rating required for the
replacement component.
The smaller replacement will cost less
to buy. It should also cost less to operate
since, generally, the smaller component
will use less energy to do the job.
How about "premium"
efficiency?
Energy system components often come
in standard efficiency and "premium"
(or greater) efficiency models. The premium efficiency models generally are
more expensive. You should always
consider buying premium efficiency
components that will meet your capacitv' reauirements. You will usuallv find
that the energy savings that you can
expect from the premium unit will pay
quite rapidly for its additional cost.
Consider new technologies
When you are considering replacing
somethine.
". there mav be other technologies that would be to your advantage to use. Many of these are discussed on pages 42 and 4 3 . Be sure to
ask your consultant or supplier to help
you explore these possibilities and do a
cost/benefit analysis.
Thinking ahead
Since equipment failures often put your
facilities off-line and under time pressure, you should develop a list of major
components that may fail, and investigate the price and availability of efficient units before they fail. This way
you will not be forced to accept an average efficiency product because of time
pressure (remember that HVAC components usually have long lives, so that
you will be forced to live with the
replacement that you choose for many
years).
And don't forget..
1
An important relationship:
HVAC/Envelope/Lig hting.
You may be able to select a smaller
replacement part because there have
been energy efficiency improvements to
your building or space since the HVAC
system was installed, for example:
the lighting system was upgraded,
and the lower wattage throws off
less heat; or
insulation or window film was
installed, or some other improvement
has reduced the heating or cooling
loads.
It is also possible that the original component was simply oversized to begin
with, something that is commonly found.
40
.
Lots of things you do to and around
your building can affect the load on
your HVAC system. Planting deciduous
trees-or keeping those you have-can
provide warm weather shade, and using
light colored roofing material and exterior wall colors will reflect heat.
HVAC
HVAC Buying Guide
Window air conditioners are rated in terms of their EER
(Energy Efficiency Ratio), which is the cooling output in BTUs
per hour for a watt of input power. A window unit with an
EER of 12.0 would use 25% less electricity to deliver the same
amount of cooling as a unit with an EER of 9.0.
Central air conditioners and heat pumps (cooling
mode) are rated in terms of their SEER (Seasonal Energy
Efficiency Ratio). The SEER represents cooling performance
over an entire cooling season and is equal to the total BTUs
of cooling delivered divided by the total watt-hours of
power used during a representative cooling season.
Chillers are rated in terms of IPLV (Integrated Part
Load Value). IPLV represents cooling performance over an
entire cooling season and is equal to the average kW of
input power per ton (12,000 BTU/hr) of cooling output.
Heat pumps in the heating mode are rated in terms
of HSPF (Heating Season Performance Factor). Similar to
SEER, the HSPF represents heating performance over an
entire heating season and is equal to the total BTUs of heating delivered divided by the total watt-hours of power used
during a representative heating season.
Fuel burning furnaces and boilers are rated in terms
of AFUE (Annual Fuel Utilization Efficiency), a percentage
rating of expected performance considering losses up the
chimney and through the walls, cycling effects, and losses
from standing pilots during a typical year of operation. It is
equal to the BTUs of heating output divided by the BTUs
of fuel input during a representative heating season.
Buy the right size
Rule number one is to make sure you are getting the right
"size" unit-that is, one which delivers the right amount of
heating, cooling, or ventilation for the space it serves. Too
large a unit can waste energy, too small and it won't be able
to do the job. Look for BTUs (British Thermal Units) of heating or cooling power. Cooling equipment is often rated in
tons (one ton=12,000 BTUs per hour). Your supplier, HVAC
service person, or perhaps a utility representative can help
determine your requirements (see more on this on p . 40).
Buy high energy efficiency equipment
The following explanation and the table below will help
you with your selections.
Efficiency standards: how to use them
to select energy efficient equipment
The Federal government has passed laws which require
manufacturers of energy intensive equipment and appliances to meet minimum efficiency levels, to use standardized
test methods to determine these levels, and to label each
product with its efficiency rating. Some states have passed
their own laws specifying different minimum standards.
What all this means to you as a purchaser is that you can
use the labels on new HVAC and other equipment to judge
the efficiency of different vendors' offerings. An important
point: always consider buying equipment that is more efficient than the minimum standard, since any additional purchase cost will often more than pay for itself in increased
energy savings.
Table 15
Check the Data and Labels
HVAC Equipment Efficiencies
Equipment
(and mode, for heat pump)
Efficiency
Rating
Window Air Conditioner
Central Air Conditioner
Electric Chiller
EER
SEER
IPLV
SEER
HSPF
SEER
HSPF
AFUE
AFUE
AFUE
AFUE
Heat Pump (Split)-Cooling
Heat Pump (Split-Heating
Heat Pump (Single Package)-Cooling
Heat Pump (Single Package)-Heating
Gas Furnace
Gas Boiler
Oil Furnace
Oil Boiler
When purchasing energy using equipment, be sure to
request energy efficiency data. The data should be an
EER, SEER, HSPF, or AFUE rating, as explained
above. The rating usually is found on a tag or label on
the equipment; it is always available in the manufacturer's literature -ask your dealer for it.
41
I
HVAC
Possible investment Projects
Once you have established energy-saving
operating and maintenance practices, you
might consider any number of modifications that will save you additional money.
Get a professional analysis
With a wide variety of HVAC systems,
there is quite a range of possible investment projects. Some of the things listed
here may be appropriate for you to consider, others not. To determine which if
any you should undertake, and which
would be the best investment, you should
get the advice of a qualified professional.
Controls, air handling,
cooling
Install one or more programmable
thermostats, which will not “forget” to
adjust temperatures for energy efficiency for the weekend or night. They are
easy to install and very reliable. Make
sure the new thermostat has the right
operating voltage and current to work
with your existing heating and cooling
system. Also, be sure the new units
have back-up batteries so they can retain
their setpoints if they ever lose power.
Install an EMS (energy management
system) to provide unified control of
HVAC functions to maximize energy
efficiency and comfort conditions (p.67).
Install load-shedding and peak shaving
devices (chiller optimization package)
that will enable you to reduce demand
charges on your electricity bill.
Install an outside air control system to
maximize the use of outside air to cool
your space and to introduce only the
amount of ventilation air needed.
Install a supply temperature reset control based on outside and inside temperature and humidity.
Install controls to reset discharge air
temperature according to outside air
temperature.
Install dampers in the exhaust ducts
that will close when the fan does not
operate.
Convert to a variable air volume (VAV)
air handling system with variable
speed drives on fan motors.
If you have cooling towers, investigate
modifying their operation to provide
“chilled water” for cooling instead of
using mechanical refrigeration (water
side economizer] for part of the year.
Control cooling tower fans to maximize the efficiency of the chiller/cooling tower system.
Install heat recovery ventilators (HRV)
to move fresh air in and stale air out of
your building while exchanging 50%
to 70% of the energy between the two
air streams. In humid climates, HRVs
with “desiccant” capability control the
humidity in the building air.
Investigate heat recovery possibilities
wherever ventilation requirements are
high (e.g., in theaters, restaurants, classrooms, indoor sports facilities) or waste
heat is escaping out of your building
(e.g., kitchen or laboratory hoods, chiller
condenser waste heat). Seep. 61.
Install a control on your heat p u m p if it
has supplementary electric resistance
heating elements, to minimize their use.
Heating and cooling
distribution systems
If you cannot turn off or control appropriate parts of the HVAC system, so much
energy may be being wasted that you will
want to consider these alternatives:
Have the system modified and zones
and separate controls installed;
Valve off or otherwise cut off seldom
used areas distant from the heart of an
extensive HVAC system, and install
local heating or cooling equipment to
serve them.
42
Install controls to vary hot water
temperature based on outside air
temperature.
Convert water circulation pump motors
and controls to variable speed drives
and direct digital controls (DDC).
Install insulation on all air ducts,
and on chilled water, hot water,
and steam pipes.
Replace any faulty steam traps.
Fuel burning
and other equipment
Replace a burner of inefficient design
or incorrect size with a modern, efficient burner of a type suitable to the
fuel being used.
Install an automaticflue damper to
close the flue when the unit is not firing.
Install turbulators in older fire tube
boilers to improve heat transfer efficiency.
In a large boiler, install an automatic
combustion control system, which
monitors the composition of the exit
gases and fine-tunes the amount of
air taken in.
Insulate hot, uninsulated boiler
surfaces.
*Replace pilot lights with electric
ignition.
a
HVAC
Other Possibilities
There are still other options for improving
your HVAC system, ranging from something as simple as a ceiling fan to an installation as unusual as a cool storage system.
Ceiling fans
Ceiling-mounted paddle fans, quite
common earlier in this century, have
made a come-back in the last decade or
two. Decorative and appealing for their
gentle motion, they also can save you
energy dollars.
hours to cool or freeze a fluid or other
medium in a storage tank. During the
day, the stored coolness is used to satisfy air conditioning needs in your building, reducing and sometimes eliminating the use of electricity-driven chillers
during peak times.
A cool storage system can save a lot
of energy dollars, but you will need
advice from your utility, energy engineer, and vendors before you can decide
whether to make the investment.
Heat pumps
In a high ceilinged space they can
help “destratify” the warm air layer
which collects near the ceiling and distribute it to the lower part of the space
for people’s comfort. This can mean that
heating thermostats need not be set as
high. Similarly, fans help to cool by
increasing evaporation of moisture from
the skin, a cooling process. Consequently,
air conditioners needn’t work as haid.
Cool Storage
When you run a conventional air conditioning system during the day, you pay
peak energy (kWh) rates and peak
demand (kW) rates to provide cooling
for immediate use in your building.
Installing a cool storage system will
allow you to save on your electric bills
by paying lower, night time, off-peak
electricity rates (T-0-U or “time-of-use”
rates) to generate and store the cooling
energy you will need for air conditioning the next day.
The idea behind a cool storage system is as simple as making ice cubes in
your refrigerator at night to cool a drink
the next afternoon. The system uses
chillers operating near peak efficiency
during the late night and early morning
Used in retrofits as well as new construction, the heat pump is aptly named:
it is an electrical device that “pumps” or
moves heat from one place to another. It
may be used both to heat and to cool.
Heat pumps are often very cost-effective replacements for packaged air conditioners with electric resistance heat.
They are generally better suited for
moderate climates than for areas with
long, cold winters.
Most heat pumps are “air source” or
air-to-air systems. In the cooling mode,
the heat pump operates like the familiar
window air conditioner, removing heat
from an interior space and transferring it
to a “heat sink,” the air outside; in the
heating mode, the heat pump may be
thought of as a reversed air conditioner
that extracts heat from a heat source, the
air outside the building, and pumps it to
the inside of the building, distributing it
through air ducts. “Water source” heat
--D
43
pumps take heat from or reject it to a
water pipe or connecting loop. Heat is
rejected from the loop to a cooling tower
or is provided to the loop by a boiler if
the loop temperature falls.
Heat pumps can be ideal for buildings requiring both heating and cooling;
the same system does both. It can switch
from one mode to the other automatically or, with a closed water loop supply,
do both at the same time for different
areas, reclaiming heat from a cooled
area and transferring it to an area in
need of heat.
Heat pumps are a very efficient type
of heating system. In addition to efficient
operation, there may be lower first cost,
lower maintenance, and space savings
compared to two separate conventional
heating and cooling systems. As a heating
unit, the heat pump works efficiently as
long as the temperature of the heat
source (usually outside air) does not
drop too low. In cold weather, its heating effort may need to be supplemented
by other sources of heat, either electric
resistance or an existing fossil fuel system. Most heat pumps have their own
electric resistance heating elements but
there are also “dual fuel” heat pumps
where gas is used for heating below a
pre-programmed temperature.
Other heat source/sink alternatives
include ground water from a stream or
large pond, or a heat exchanger buried
in the earth for a “ground coupled” or
“geothermal” closed loop system in
HVAC
which water is pumped through buried
plastic pipes to capture heat energy
from the earth. All are practical,
depending upon local conditions. In
addition to HVAC type heat pumps,
there are heat pump water heaters
(see page 491.
Comfort and Productivity
Many energy investments are evaluated
primarily on an economic basis related
solely to the equipment or installation
itself: what’s the financial cost, the
payback, the life of the improvement,
the reduction in the use of energy?
Particularly in relation to HVAC
improvements, the human side is essential to consider: what gains in comfort
and productivity will result if we do A
or B? How will a particular improvement freshen the air, or cool or warm
employees or customers? As you evaluate your HVAC system and possible
improvements, be sure to keep these
considerations in mind, although not so
easily measured in dollars and cents.
An important subject: Indoor Air Quality
Fresh air is very important to the health and comfort
of building occupants. Most newer buildings have
heating and cooling systems that incorporate
adjustable ventilation dampers, ducts, and blowers
that bring in fresh air and exhaust stale air. The
amount of fresh air delivered is dictated by building
and health and occupancy codes.
Some buildings, such as those with hot water or
steam heating systems, may not have an active ventilation system to draw in fresh air (sometimes they do
have exhaust fans to get rid of stale air, as in kitchens
or restrooms). In those buildings fresh air comes in, or
“infiltrates,” through open doors and windows or
through cracks. When such a building is “tightened
up,” air quality can deteriorate because the building
no longer “breathes” as much.
The same air quality problem can occur in buildings
which do have ventilation systems but where ventilation rates have been reduced too much (this was sometimes done as an energy conservation measure, as the
less air there is that needs to be “conditioned” the less
energy is needed for cooling or heating it).
For a time, in the late ’70s and early ’80s primarily,
lower fresh air ventilation rates were recommended.
These lower levels have sometimes contributed to indoor
air quality problems (or “sick building syndrome”).
At present, ASHRAE (the American Society of
Heating, Refrigeration and Air Conditioning
Engineers) recommends that 15 to 20 cubic feet of air
per minute be brought into the building for every
occupant. This fresh air, if properly distributed within the building, should eliminate potential indoor air
quality problems and maintain high levels of comfort
and productivity.
If you require increased ventilation rates, which
can require increased energy use, be sure to consider
heat recovery ventilators or other ways to improve
energy efficiency.
Take a look at your present
HVAC system, using the convenient “walk-through” self-audit
form on p.64.
44
H
ot water may be used in your building for “domestic”
purposes-e.g., for showers or for washing hands in
employee lavatories-or it may be used in specialized
machines such as restaurant dishwashers or commercial laundry machines. Some industrial processes use a lot of
hot water, and warming the 50,000 or more gallons of water in
a swimming pool can consume a lot of energy, too.
In some industries and in motels, hospitals, nursing homes,
restaurants, car washes, apartment buildings, athletic facilities
and dormitories, a major part of every energy dollar is used to
heat water.
If you have a heated swimming pool or use hot water for
laundry, dishwashing, or industrial processes, please see
pp. 55-58 for more on how to save energy dollars.
tem’s boiler by means of a “tankless coil” (seep. 48). The heat
source in still other systems is waste heat recaptured from an
industrial process, air conditioning or lighting system, large
computer installation, or other source. Finally, individual electric resistance heaters-“point of use” heaters-may be located
at each sink, machine, or other point of use.
Storage. Most systems have a storage tank; tankless coil
systems and point source heaters either have no tank or very
limited storage capacity.
Major ways
- to save
No matter how much hot water you use, there are many ways
to cut back on unnecessary energy use. These fall into several
basic categories:
Reducing the heat loss in the system. Many hot water sysWhat type of hot water system
tems are “standby” systems; that is, the hot water is used only
infrequently but nevertheless is kept available all the time. If
do you have?
the system is poorly
Or poorly
poorly
A hot water system consists of: a water heater; possibly a stormaintained
the
water
that
is
heated
and
kept
“at
the ready” in
age tank where the heated water is kept until needed; distributhe
storage
tank
and
distribution
pipes
can
waste
energy as it
tion pipes (unless the heater is located right at the point of
loses heat to the surrounding air.
use); a circulating pump, if needed, to move the water through
Reducing the temperature of the hot water; it often is
the pipes; and controls to regulate the temperature and the
much
hotter than necessary*
pump. In most small systems, the heating unit and storage tank
Reducing
the amount of hot water used.
are combined, while in large systems
Reducing the time the water heater
they usually are separate.
operates.
Heat Source. In most systems, the
Maintenance.
water is heated using electricity or gas.
In electric resistance systems, heating elReduce heat loss
46
Investments in energy saving
technologies, including using a
Reduce the temperature
46
ements are immersed in the water in the
“free” source to heat the water.
tank. In other electric systems, a heat
pump extracts heat from the air or from
ground water (seep. 38). In gas-fired systems, a burner heats the tank from below.
Other systems collect heat from the
sun or get it from the space heating sys-
Reduce the amount used
Reduce the time the
heater operates
Maintenance
Investments
47
48
48
49
H O T WATER
Reduce Heat Loss in the System
installing a tank “wrap” or blanket on a
hot water storage tank will be an
extremely cost-effective way to save
energy dollars. A blanket is inexpensive
and easy to install, and you can find one
to fit your tank at a hardware, building,
or plumbing supplier.
At the same time, insulate the
exposed hot water supply piping in
your utility room, and repair or replace
any existing insulation which needs it.
Foil-faced fiberglass insulation or foam
insulation sleeves may be used. The
fiberglass is installed in strips tied to the
pipe with wire or tape every six to eight
inches, foil facing out. The foam simply
slips onto the pipe through a slit in the
sleeve; the slit is then sealed with tape.
Install or repair insulation
on the hot water storage
tank and distribution pipes
If you have an uninsulated or poorly
insulated hot water storage tank or uninsulated distribution pipes, adding an insulating jacket or “wrap” to the tank and
installing tubular insulation on the pipes
will reducs “stand-by” heat losses. If the
tank is hot or warm to the touch, it needs
insulation. Test a metal tank by feeling
the temperature of some other metal
object in the same area, and comparing.
Only in the last few years have water
heater manufacturers been installing
really adequate insulation on the tanks.
So, in the great majority of cases,
Reduce the Temperature of the Hot Water
Often the water heater control is set
quite high in order to overcome heat
losses from the tank and distribution
pipes. With proper insulation of the
storage tank and distribution pipes (see
above), you should be able to reduce the
temperature control setting.
However, frequently the heater simply delivers water that is hotter than
needed. At the faucet, this very hot
water may end up being tempered by
adding cold water to reach the desired
temperature.
When you are sure there is adequate
insulation, check the setting on the temperature control. Then use a thermometer to measure the temperature at the
faucet nearest the tank and at the major
hot water use-points (e.g., the dishwasher, sink, or washing machine). Adjust
the hot water tank temperature control
until the desired temperatures are
reached at the points of use.
Making the temperature adjustment
is often quite simple. Mark the current
setting on the dial using a permanent
marker, and then turn the dial to a lower
setting. Then re-check the water temperature at the points of use and readjust
the water heater control accordingly.
Although the adjustment is simple to
do, it may take some time-since a large
volume of water in the storage tank must
warm up or cool down, it will take a
number of hours before the new setting
is reflected in the water temperature in
the tank and at the tap.
If the temperature dial on the tank
is not visible, you may need to remove
a few screws and a cover plate to get at
it; if you have an electric water heater,
make sure you shut off the electric current to the heater before you do this
(you could also consider having an
electrician do this for you].
Table 16
Hot Water Temperatures
105°F
105°F
160°F
180°F
Handwashing
Showers
Laundry *
Dishwasher rinse**
Check code requirements. Even lower temperatures may be
practical with some soaps and detergents.
* * Most dishwashers need water to enter at 140°F to boost it
to 180°F. Also see “Machines” section.
*
46
If you have a large commercial water
heater, your service technician should
perform these checks and adjustments.
HOT WATER
Reduce the Amount of Hot Water Used
FAUCETS &
SHOWERHEADS
Install water conserving
showerheads
Showerheads are now available that
provide satisfying showers using only
2-3 gallons a minute, in contrast to the
five or more gallons per minute used
by many older models. In places such
as motels and athletic facilities, where
showering uses a lot of hot water, these
devices can pay for themselves very
quickly.
But be careful in your choice: all
water conserving or “low-flow’’showerheads are not created equal! If the flow
is too low, people may just stay in
longer, using more water and defeating
your purpose. Others are too harsh, and
you will be showered with complaints if
the showerhead doesn’t give a truly
comfortable shower.
A well designed water-saver showerhead may cost about $10-15. Though
more expensive, it is recommended over
the very inexpensive disk insert flow
restrictors, which give very poor quality
showers. Research shows that user
acceptability of good replacement showerheads is extremely high.
You can check the flow of an existing
showerhead by running the shower at a
normal rate of flow and timing the filling of a bucket of known size.
Install self-closing
hot water faucets
or mixing valves
A spring operated faucet valve will
make sure hot water isn’t left on unnecessarily. Where the need for water varies
and may be considerable, such as in a
kitchen sink, a foot operated valve may
be most useful and will leave the operator’s hands free.
The type of self-closing valve most
frequently used in lavatories operates
by depressing a hand lever; check to
see whether a delay mechanism (e.g.,
15-second delayed action) is required
by your state or local codes, or whether
there are other code requirements which
must be met.
Installing a single mixing valve is
another approach. It prevents the waste
of both hot and cold water by reducing
the time the water from two separate
faucets would be on as the person tries
to “mix” the water from two faucets in
cupped hands.
Install flow restrictors and
aerators in sink faucets
While water-saver showerheads will
perform better than restrictors in showers, inexpensive and simple disk-type
flow restrictors are suitable for sinks.
An aerator, which “spreads” the
water, can also be installed to assure a
satisfactory though lower flow of water
from the tap. If you are going to replace
faucets, some of the newer ones come
equipped with an aerator or a low-flow
head.
Use labels at faucets
By placing a self-stick “Please Turn Off
the Water” label near each faucet, you
can encourage people to conserve both
water and energy.
Consider installing
occupancy sensing
contro Is
Flow restrictors for lavatory sinks
may be located at the shut-off valve (i.e.,
below the faucet handle) to prevent loss,
or above the aerator. In places such as
kitchens or janitors’ sinks where speed
in filling a container, or force of the
flow, would be important, you may not
want to install flow restrictors.
47
Just as occupancy sensors increasingly
are being used to turn lights on and off
in relation to actual need, occupancy
sensors are becoming more common for
automatically controlling water usage in
restrooms open to the public (e.g., in
hospitals, universities, entertainment
and athletic facilities).
Typically consisting of a photocell
and solenoids, a sensing control may be
installed at a sink to turn the tap water
on for a specific interval, or at a water
closet to control the flushing.
H O T WATER
Reduce the Time the Water Heater Operates
Turn off the water heater
itself, permanently or
temporarily
Your water heater may supply only the
lavatory sinks. If state or local codes
permit, and employees don’t mind, you
may want to shut off this heater entirely
or reduce its operating temperature.
If you normally use a lot of hot water
but are closed for two or more days in
a row-e.g., weekends or vacation shutdowns-it may pay to shut off the water
heater for the unoccupied period. It
may even pay to install a seven-day time
clock so this will happen automatically.
Turn off just the
circulation pump when hot
water will not be needed
Your hot water system may include
a circulation pump that assures that
hot water is available at all times at all
faucets and other points of use-without delay. An operating pump consumes energy, and it also means that
your water heater is heating and reheat-
ing water to overcome stand-by heat losses, even if no hot water is being used.
Consider turning the circulation system off when your space is unoccupied
and hot water is not needed-e.g., at
night, on weekends, during shut-down
periods. You can install a simple timer
to do this, or use more sophisticated
controls that will “learn” your operating schedule and turn your system off
and on several times a day if need be
(see EMS, p . 67). With these controls, it
is essential that distribution pipes be
properly insulated.
Maintenance
Eliminate hot water
leaks and drips
higher concentrations of lime and other
minerals in your area, which may make
it necessary to flush as often as every
month. Experiment for a few months
to see what the proper interval is, or
ask your water company.
It always pays to make inexpensive
repairs on leaky hot water faucets,
shower-heads, and pipe joints. And
delaying a repair is not a good idea,
since most leaks gradually get worse.
Many repairs, such as replacing a sink
faucet washer, you can do yourself
quickly and easily, and at virtually no
expense.
Test and adjust
a fuel-fired heater
A fuel-fired (gas or oil) water heater can
waste energy if it is not burning the fuel
properly. Have such a heater checked to
reveal whether excessive heat is being
lost up the stack and whether the fuel is
being incompletely burned; this involves
measuring flue temperature and carbon
dioxide (CO,) and oxygen concentrations.
Your service technician will be able
to make the necessary adjustments to
improve the heater’s efficiency. If you
have a fuel-fired heater, you should
have it checked and cleaned at least
once a year, perhaps at the same time
your boiler or furnace is being tested
and adjusted.
A few minutes, and a few cents for a new
washer, are all it takes to fix a leaky faucet.
Clean out sediment
Any tank-type water heater will lose efficiency if sediment accumulates in the
bottom and acts as an internal insulator
to inhibit transfer of heat from the heating elements to the water. To make sure
these deposits don’t build up, periodically open the drain valve near the bottom of the tank and draw off water until
it runs clear and the sediment has been
removed (probably two to five gallons of
water will be enough to drain). For large
commercial equipment, this should be
done by a service technician.
Flushing the tank every six months
should be sufficient, unless there are
48
HOT WATER
Other Ways to Save
Replace a
tankless coil with
a different-type heater
In some buildings, water is heated by
the central heating system by means of
a “tankless coil” installed in a gas-fired
or oil-fired boiler. These systems have
little or no storage capacity, so the entire
furnace or boiler must operate to heat
even a small amount of water. Tankless
coils can be more efficient than standard
water heaters when used with new,
high-efficiency boilers and down-sized
storage tanks. But if your hot water
needs are small or your heating loads
are low, replace this unit with an efficient storage tank type water heater or
with small “local” heaters instead.
Switch to “local” storage
tank type heaters
A large central heater with long runs
of distribution piping can waste a lot
of heat energy, particularly if poorly
insulated and if there is relatively little
need for hot water. Depending on your
hot water needs and the age and effi-
ciency of the existing system, it may
make sense to abandon the old system
and replace it with one or more small
storage tank type water heaters very
close to the faucets or other points of hot
water use (e.g., one in each lavatory).
Saving energy
in your cold water
system
A water cooler uses electricity to
cool and re-cool the water round
the clock, even though most of the
time the water isn’t being drawn
(another example of “stand-by”
energy losses). You may be able to
raise the chilled water temperature
or to disconnect the refrigeration
unit by removing the cover and disconnecting the compressor.
Simply unplugging a freestanding water cooler is another option,
if people will be satisfied with room
temperature water. This will save a
little on your electric bills, and it’s
vezy easy to do!
Use cleaning materials
that save hot water
For more on this,see p . 57.
Heat or use hot water
during off-peak hours
If your water is heated by electricity,
you may be able to take advantage of
lower water heating or off-peak utility
rates (often called “T-0-U” or time-ofuse rates) which may also reduce your
demand charges. Ask your utility if this
is possible (see page 72). Although this
will not save any energy, it can lower
your electric bills.
To benefit, you will have to reschedule your heavy use of hot water (e.g.,
laundry or dish washing) to off-peak
hours. Alternately, you can store water
heated at night at off-peak rates for use
during peak hours. If you can reschedule adequately, it may be practical to
install a timer that turns your water
heater off entirely during on-peak periods or turns off the bottom heating element in a two element tank. (Some uti1
ities provide these controls to customers on these rates.)
Investments in Energy Saving Technologies
Significant technological advances have
been made in heating water efficiently
and using waste heat produced by
equipment and processes. Investing in
one of these technologies may provide
long term savings.
Consider changing
to a high efficiency
water heater
Consider a heat pump
water heater
The most energy efficient water heater is
a heat pump water heater (HPWH).
It is available either as an integral unit
incorporating a storage tank, or as an
add-on to your present water heater
(in the latter case the heat pump
heats the water, and the storage
tank stores it).
-
-
If you are replacing your water heater,
replace with high efficiency units. As
with most energy using replacements,
the additional cost for a high efficiency
model is quickly paid back in energy
cost savings.
Add-on
49
Integral
HOT WATER
The HPWH extracts heat from the
surrounding air and transfers it to the
water being heated. It is used in a wide
variety of settings, including: restaurants, laundromats, motels, apartment
buildings, indoor and outdoor pools,
athletic facilities, and small-scale
industrial processing operations.
Since the HPWH cools the air as it
tranfers heat to the water, it can offer
added energy savings when installed
indoors in warm and huniid places
needing air conditioning and dehumidification (e.g., cooking and laundry
areas, health and fitness centers, etc.) If
installed in an unheated interior space,
it will not operate as efficiently and
the cooling benefit will be limited.
Efficient and cost-effective HPWH
operation requires careful site-specific
planning and design of the installation
by experienced professionals.
Install the new water heater closer to the point of use
If you are replacing an old heater, or
installing one for the first time, locate it
close to the major point of use (washing
machine, etc.) to minimize heat losses
in the distribution pipes.
Install a heat
reclamation device
One of the most intriguing ways to save
energy dollars is to recapture and reuse
”waste” heat before it has been truly
lost. In a commercial laundry or restaurant, for instance, heat in the to-be-discarded washing or rinsing water may be
recaptured before the water goes down
WITHOUT Heat Recovery
Dish washer
Water
heater
Sources other than
waste hot water may be
tapped. See more on this
-.
on p . b l .
Install solar
water heating
Solar space heating is by
no means new, going
8
HOT water back to prehistoric south
Fresh cold
facing caves and to
water
down drain Roman atrium (courtyard) houses. On the
other hand, much of
WITH Heat Recovery
solar water heating technology has come into use
Dish washer
only in the last couple of
decades. The type most
often seen now is the
“active” system with
solar roof panels that
absorb the sun’s heat and
water transfer it to the water.
down drain
Solar is frequently used
to
preheat water, with a
Heat reclaimer
final boost added by
another heater. Solar systems are often
the drain, and used to pre-heat fresh,
backed
UP by conventional water
cold water. As shown in the schematic,
heaters
to Provide for cloudy periods.
the two water supplies are kept separate
One
of
the most cost-effective solar
and the heat is transferred through a
applications is for pool heating, where
heat “exchanger” or “reclaimer.”
water need only be warm, not “hot,”
Whether the investment in the reclaallowing inexpensive unglazed collecmation device can be warranted
tors to be used.
depends primarily on the amount of
Whether solar would be a good
water being used, its “discard temperainvestment for you may depend on
ture,” and the cost of the installation.
many factors, including your hot water
More and more of these systems are
needs, building orientation, and how
being installed, however, and you
warm and sunny Your location is.
should be certain to investigate the possibility if you use a lot of hot water.
R O O ~ ~ Osolar
D
Check Out
Your Hot
Water
Take a look a t your present
hot water system, using the
convenient “Walk-through”
self-audit form on p.63.
50
all rely on energy powered equipment that transforms or
“processes” material in some way or which does some other
job that is best done with an energy assist.
In fact, “process” energy may be the big item in your total
energy expenditures, and your cost for all the other energy
uses covered in this manual-heating and cooling your building, lighting, domestic hot water production-may be completely dwarfed by the amount you pay for process energy.
Even if your operation is relatively small in size, as are many
businesses such as restaurants, bakeries, automotive paint
shops, printing, and electroplating plants, your process energy
costs may be very important expenditures for you to control.
If your operation relies heavily on heat which is produced
by your own heating system, you will want to review the earlier section on boilers, furnaces, fuel burners, and other heating
system components. However, many industries use highly specialized heating, cooling and other equipment, the explanation
of which is beyond the scope of this guide. Pages 60-61 will
give you a brief introduction to this subject and suggest how
you can get the industry-specific information you need.
How much do you pay for process energy?
It is important for you to know how much process energy you
use, and what it costs, so you will have a baseline for savings
and for determining whether possible capital improvements
would be sound investments.
Basically, there are two ways to estimate how much you pay
for process energy: estimate how much you pay for nonprocess energy-for your lights, heat, and air conditioning, for
instance -and subtract those figures from your total energy
hills; or estimate your process energy use directly, either by
using meter readings if equipment is separately metered, or by
calculating hours of operation and energy consumption for each
piece of equipment (you may need to note specific model numbers and contact the manufacturers to get some help with this).
With energy consumption figures at hand, you can then
use unit costs (e.g., cents per kilowatt hour) and multiply to
get the answers. In the case of electricity, however, with peak
load factors, demand charges, and other possible variables you
may want to ask the help of your utility or an energy consultant.
To give meaning to your figures, you may also want to use
one or more of these units of measurement:
per hour of operation
per unit of product
per square foot of building
per employee
12 Basic rules
Office machines
Refrigeration and freezing
Cooking
Washing and drying
Swimming pools
Electric motors
Industrial processes and
shop equipment
” Free” energy
52
52
54
55
57
58
59
60
61
MACHINES
Office Machines
The fastest growing type of energy users
in commercial buildings. As we shift
from a manufacturing to an information/service economy, office machines
are becoming an increasingly important
type of energy user in the work environment. In fact, although lighting, air conditioning, and heating consume a large
part of each energy dollar, office equipment loads are the fastest growing energy
use in businesses and institutions.
One reason for this is that we rely
more and more on machines to boost productivity, and so there are more machines
per worker. For instance, where a group
of offices may previously have been
served by a single typewriter and a single
If left running all day long, the computer in this
office may use half as much electricity
as the lights! If left on all night, it may waste
more power than the lights used all day!
~
~
6-Office suite and its equipment
Before
Rated Watts*
Q 138 watts
Q 450watts
1 typewriter
1 photocopier
Total watts for office
Now
6 computers
6 monitors
2 printers
1 large photocopier
1 fax
Q 483watts
Q 161 watts
@ 759watts
Q 1,800 watts
Q 65 watts
Total watts for office
Actual Watts**
138
450
41
135
588
176
2,898
966
1,518
1,800
65
869
290
455
540
20
7,247
2,174
6,659 watts
1,998 watts
1,132%
1,132 %
~~
Difference
* These are nameplate ratings.
“At 30% of nameplate ratings (see explanation in led below).
small photocopier, those same offices
may now be equipped with individual
computers, monitors, and shared laser
printers, and by a much larger photocopier in the work room. Where hundreds
of watts was the norm, thousands now is
the rule. And in some offices the energy
used, per worker, by the computers and
printers and photocopiers left on all day,
may be more than that used by the lights!
A note about machine ratings
and energy use. Research indicates that
actual electric use ranges from Zo% to
40% of wattage ratings (Le., a machine
rated at 500 watts will, on average, actually use 100-200 watts of electricity).
Some equipment such as laser printers
and copiers use much less energy in the
“stand by” mode than they do when
running. It is reasonable for you to use
30% to estimate actual energy use for
your savings calculations.
12 Basic Rules for Reducing Energy Consumption by Machines
7.Manage your electricity use to avoid high demand
No matter what the specifics of your use of process energy,
the following may be the key to significant energy savings:
1. Turn it off whenever Dossible.
2. Don’t forget the “hidden” machines and equipmentthe almost silent computer, the photocopier in the
little room down the hall, the elevator motor at the
top of the shaft.
3. Adjust controls to a temperature, speed, or other
setting that uses less energy but still does the job properly.
4. Use your equipment more efficiently-for example,
load it to capacity rather than do partial loads.
5 . Clean, tune and adjust, lubricate, replace worn parts,
and otherwise maintain the equipment.
6. Don’t create unnecessary problems-for example, don’t
release process heat inside your building where the air
conditioning system must then cool it.
charges (see p . 70). This is a very important thing to do if
you use lots of electricity for process energy. While it is
not truly an energy conservation process, in that you still
may use the same amount of electricity, it can decrease
your electric bills.
8. When equipment that is worn out must be replaced,
choose the most energy-efficient replacement, properly
sized to meet the needs of the job.
9. If cost-justified, do a major overhaul to make equipment
more energy efficient.
10. If cost-justified, replace equipment that still operates,
with more energy-efficient equipment.
11. Install new automatic controls, if cost-justified.
12.Consider using waste heat to advantage-for example,
excess process heat may be used to help warm the
building or heat water, or even used to create steam
and electricity.
52
MACHINES
Energy savings potentials
Turn off machines when not needed
Select smaller machines to use
Reducing energy use by machines may
be an especially important part of your
energy saving efforts, since in some
offices all the energy savings in more
efficient lighting and HVAC can be more
than offset by the increased energy used
by a single new computer and its printer!
Wasting energy “standing by” or forgotten. Office machines use energy
to do one or more of the following:
move something (e.g., a piece of paper
through a copier); heat something (e.g.,
the toner in the copier); and cool the
machine (most have a fan to keep air circulating to dissipate heat from the motor
and heating element). So they cost you
energy dollars for their operation, and
the heat they throw off adds to the air
conditioning load.
But how much of the time are they
doing any work? If you think of it, many
machines that are kept running are actually used relatively little; frequently they
are only “standing by,” waiting to be
used. Or they are left on unnecessarily
when the area is unoccupied.
While there are many techniques for
saving energy in lighting, heating, and
air conditioning, there’s basically only
one way to save energy used by your
present office machines: turn them off
when not needed.
Make sure that machines are turned off
at the start of unoccupied hours (e.g.,
nights, weekends, etc.) and that machines
which really don’t need to be kept running all the time are turned off during
work hours if they will not be needed
for some period of time. However, if
warm-up and start-up procedures are
time consuming or complex, in the
interests of productivity it will make
more sense to keep the machines running at all times so they are immediately
available for use.
If you are going to be considering an
energy management system (EMS-see
p . 62), it may be able to control off-times
for some of your machines as well as the
HVAC, lighting, and other energy users.
If there is a choice of a small or a large
machine to turn on and use or to leave
running-e.g., a photocopier-select the
smaller one.
How many watts?
Check the nameplate or other location on the
machine. Usually the energy rating is in amps
and volts, not watts. A good approximation foi
converting those numbers to watts is:
~
= -watts
amps x -volts*
Then multiply by .30 (Le., 30%) to find the
wattage to use for your energy calculations:
-watts
x .30 = -watts for
savings calculations
(see “A note about” on p.52)
Check energy use when you buy
When buying machines, consider their
size and energy use when making a
selection; low energy use in stand-by
mode is a desirable feature. However,
once again, office machines and their
energy-using features can be so important for workplace productivity that
energy consumption clearly m a y be only
a secondary consideration.
The Energy StarSM
label identifies personal computers, monitors, printers,
,,-copiers
-and
,fax
machines which meet
EPA energy efficiency
standards. This equipment can enter a low-power “sleep”
mode when not in use and can awaken
automatically when needed again.
Table 17
Annual Savings*
from fewer hours
of machine operation
your savings if the
operation of machines
rated at 1,000 watts* *
is reduced by this
many hours per day:
Your
electric
rate per
kWh:
Use 115 volts if the machine rating states a voltage range
_
Don‘t forget to turn off the big photocopierit can be a “forgotten” machine if located in an
out-of-the-way workroom.
How much can you save? It depends
on the number of machines, their energy
requirements, and how much they are
left on when not needed. Use the selfaudit sheet on p. 65 to make your inventory; use Table 1 7 to find the savings for
each 1,000watts of name plate ratings.
Just two computers rated at a total of
1,000 watts and needlessly left on all
night might be wasting $100 or more in
electricity. If there were 100 computers,
the figure might be $5,000 or more!
53
_
_
_
~
~
5t
$ 8 $16
$23 $31
33
44
22
11
7t
28
42
56
14
9t
34
51
69
llt
17
61
81
20
41
13t
70
94
47
15t
23
79 106
17$
27
53
59
88 119
30
19e
‘ Assumes 5 days per week, 52 weeks per year.
* * Nameplate ratings: the savings figures in this table,
however, are based on 30% of name plate ratings.
All figures rounded to nearest dollar.
$62
87
112
137
162
187
212
237
MACHINES
Refrigeration and Freezina
U
Do necessary maintenance
Refrigeration and freezing systems can
be responsible for a large part of total
energy use-for example, perhaps 50%
in a supermarket!
Condensers won't have to work so hard
if they are cleaned regularly so that heat
transfer surfaces are free of dirt and
scale. Coils should also be cleaned and
refrigerants checked. For all this, follow
manufacturers' instructions.
Types of systems
Refrigeration and freezing systems are
differentiated primarily by their operating temperature-down to 20°F for
medium temperature (MT) systems and
down to minus 25°F for low temperature
(LT) systems. They may be walk-in, or
have open, glass door, or coffin-type
units. The greatest energy saving potentials are in the MT systems.
Operation and
Maintenance
Refrigeration units and freezers can
waste energy in many ways, including:
controls set lower than necessary, doors
that don't close completely, overhang,
and improper maintenance. Following
manufacturers' recommendations is especially important. If you don't have the product literature, contact the manufacturer.
Set controls only as low
as necessary
Set temperature levels only as low as
you need to to preserve the particular
type of food or make it appealing to customers. Check present temperature levels with an accurate thermometer. And
in the cooler part of the year, make sure
to maintain the lowest possible head
pressure at which each unit can operate
(call in a refrigeration contractor to
determine the right settings).
Replacing equipment and
modifying your systems
Improve refrigerator, freezer cases
If you don't already have them, glass
doors or plastic curtains can save energy
and retard spoilage. Other effective
modifications to open, multideck display cases include improved air curtain
performance and horizontal lights. In
cases that have doors, energy can also be
saved by reducing door and frame heater
use and reducing anti-condensate heat.
Table 18
Commonly Used
Refrigeration Levels*
(degrees Fahrenheit)
~
Frozen Food
- 8"
Ice Cream
-1 4"
Delicatessen
35"
Beer, soft drinks
40"
Select efficient new
and replacement equipment
* Review with your refrigeration contractor to assure proper levels for your particular needs.
Protect from unwanted heat
This means using night covers on refrigerator and freezer cases (as long
as they do not cause frost buildup or
compressor damage-consult the manufacturer first). It also means removing as
many lights as possible from inside the
case, and making sure that units are not
located in confined areas where there
might be a heat build-up.
Do not overload
Stocking a case over the load lines can
make the unit work harder and longer
to cool the extra products. If the capacity of the unit is exceeded, overcooling
and undercooling (and product deterioration) can result.
A
54
f
High efficiency compressors are commonly available with EERs ranging from
7 to 9 for medium temperature systems
and 5 to 6 for low temperature systems.
Although your equipment and operating
conditions will influence your actual
savings, efficient compressors can be
expected to reduce compressor energy
use by approximately 15% in MT systems and 5% in LT systems. When you
buy entirely new units, get the right size
for your needs and be sure to compare
models on the basis of their energy efficiency. Remember, the higher the EER,
the more efficient the unit. Combining
many small compressors into larger rack
type systems should be considered.
Glass doors
on frozen food
a
MACHINES
Other possible investments
These include: defrosthecooling cycles,
case humidity controls, and heat recovery systems (seep. 62 for more on heat
recovey]. In existing stores with frost
and condensation problems and in new
stores in humid climates, desiccant
dehumidifiers are one possibility,
although installing heat pipes may be
more effective and less costly.
Reportedly, a typical supermarket can
save 12-15% on refrigeration costs by
using heat pipes. Also consider: floating
head pressure controls; reducing lighting
energy in refrigerators; installing air
economizers; controlling the evaporator
fan on-time; two-stage compression; and
variable speed control of compressors.
Ask your refrigeration contractor about
all these possibilities.
I
1
I
,
,
1
1
i
I
I
~
I,
Don‘t air condition
your store the
expensive way!
Many food stores rely on refrigerator
case spillage of cold air to provide air
conditioning. The refrigeration units
that deliver this cooling typically have
EERs (energy efficiency ratios] ranging
from 5 for LT cases to 8 for MT cases.
In contrast, the HVAC systems for
these stores may have EERs of 10 or
more. Since the building air conditioning system can provide store cooling
using 40% less electricity than the
refrigerated display case, you should
make sure to minimize cold air
spillage wherever possible.
I
i___
_____
~
- - .- -
__
Cooking
Cooking uses a lot of energy even under
the best of circumstances. Wasting energy unnecessarily not only costs you
energy dollars directly, but the extra
heat generated adds to the load of your
ventilating, air conditioning, and refrigeration equipment and can increase the
fatigue of kitchen employees.
Use only as high a temperature
as is needed
Equipment Operation
Turn equipment on only
when necessary
If you’re in the habit of turning on all
the equipment first thing, and leaving it
on all the time whether or not you’re
using it, you may be wasting a lot of
energy. With the exception of equipment
that needs to be preheated, do not turn
anything on until you’re ready to use it.
Staggering initial start-up of electrical
equipment can help hold down demand
(see p .70).
An open-top range needs no preheating, 10 to 15 minutes probably is
enough for a range with a solid top, and
20 minutes should do for a fryer. Make
sure that what you’re cooking in the
oven requires that the oven be preheated; it’s a waste of energy to turn on an
Control of new high-efficiency fryer, set at economical 330’ level.
empty oven when you could be using
that heat to start the cooking.
If your broiler or griddle has more
than one burner, turn on only as many
as you need. For your broiler, fryer, or
griddle, turn the heat down between
cooking operations (orders) and turn it
off entirely during slack periods. If you
have a new infrared broiler, you can
turn it off between broiling operations
because it takes only about a minute to
preheat.
55
Temperatures that are too high not only
waste energy, they also give poor cooking results-dried out food with poorer
flavor. Generally, use medium or low
heat. It’s usually enough for light frying,
and in broiling and roasting it will
reduce shrinkage and retain juices, flavor, and tenderness. High speed modern
fryers usually work best at around 330°,
a temperature that will prevent the fat
from breaking down. The energy saved
by cooking at lower temperatures more
than offsets the energy used in the
longer cooking times.
Match the equipment to the job
Don’t use a utensil that is too small for a
burner; excess energy escapes uselessly
into the air. For frying, use your fryer,
not the range top. On solid top ranges
you should use flat bottomed utensils,
but on an open top gas range the gas
flame will conform to any shape bottom.
MACHINES
Cook as efficiently as possible
On solid-top ranges, when possible
group the utensils on one part of the top
so you use no more burners than necessary. On open-top gas ranges, adjust the
flames so only their tips touch the bottom of the utensil. Try not to open oven
doors unnecessarily to check on foods;
it lets heat escape. When foods can be
baked or roasted at the same temperature, try to cook them simultaneously in
a fully loaded oven.
If you can cook things in large volume, it may save energy. Some foods
can be cooked partially or completely in
advance, then finished or reheated later.
If freezing is necessary for preservation,
however, by the time you have cooked,
frozen, thawed, and reheated the food,
you may have used more energy than if
it were cooked in smaller quantities.
And there may be flavor and nutritional
losses in some cases.
Upgrading the kitchen
for energy efficiency
Select new energy efficient
cooking equipment
Controls are extremely important
and often are the main energy-saving
feature. Some controls are computerized
and can automatically time the cooking
of particular foods.
Improve ventilation
and exhaust systems
Adequate ventilation is needed to rid
the kitchen of heat, smoke, odors, and
grease vapors and to meet safety and fire
codes. Too much ventilation, however,
can waste energy both in running the
ventilation equipment and also in conditioning the air that must replace the
exhaust air.
One of the most effective kitchen
modifications for energy efficiency and
for kitchen staff comfort is improving
the ventilation system. This can include
installing side curtains on cooking
equipment to reduce the necessary
exhaust fan velocity, and installing an
energy-efficient exhaust hood which
draws in outside air at the perimeter of
the hood and substitutes it, in the
exhaust air stream, for conditioned air.
One manufacturer claims that energy
savings from installing this type of hood
can amount to thousands of dollars a
year. This equipment is now quite common and well proven.
Your selection of cooking equipment
can also affect your kitchen’s ventilation
requirements: one of the energy advantages of convection and microwave
ovens is that they don’t need outside
ventilation.
Consider heat recovery possibilities
With suitable equipment, the heat generated in the kitchen can be captured
and put to good use rather than discarded. Exhaust air can be used to preheat
air for the HVAC system to use in the
heating season. Heat from refrigeration
equipment and high temperature dishwashers can be used to pre-heat water.
Waste heat can also be used to operate
desiccant chillers, which remove
humidity from the air, and a heat pump
water heater can recover excess heat
from the kitchen and use it to heat the
domestic water. A building loop (water
loop) heat pump is ideal for recovering
heat to use elsewhere in the building.
In addition to such things as reliability,
durability, performance (quality of food
cooked), capacity, and come-up time,
energy efficiency should be a prime concern when you select new equipment. And
there is quite a variety of energy efficient
ovens, fiyers, and other cooking equipment
on the market. Be sure to consider:
Infrared fryers;
Convection ovens, including steamer
models, which are good at keeping
the food from drying out;
Microwave ovens (and at least one
manufacturer offers a convection/
microwave oven which can be used
in either mode, or in both modes);
Specialized equipment designed
to cook a particular food very
efficiently, such as a pizza oven.
Energy efficient exhaust
hood draws in outside
air instead of wastefully
exhausting conditioned
air from the building.
56
a
MACHINES
Washing and Dryina
J
Washing and drying, whether of laundry
or dishes and utensils, can he very
wasteful of energy because large volumes
of water or air are heated, frequently quite
high, and then almost immediately disposed of. In addition, hot water systems
are often very inefficient. Basic ways to
reduce energy waste include:
Reduce standby losses and system
inefficiencies.
Reduce temperatures and pressure
as much as possible.
Use equipment more efficiently.
Reclaim heat for use again in the
process or for some other use.
Always buy energy efficient equipment.
Reduce hot water stand-by losses
and system inefficiencies
The earlier section of this guide on hot
water contains quite a number of costeffective suggestions,-including:
repairing leaks;
insulating storage tanks and distribution pipes;
cleaning out sediment;
turning off the water heater when not
in use for a period of time (a time
clock can do this on an electric heater);
shutting down the hot water circulation pump when not needed; and
testing and tuning up fuel-fired heaters.
For these and other suggestions, please
refer again to pages 45-48.
code requirements. Some machines can
operate at lower temperatures (12Oo-14O0)
by using a bleach or sodium hypochlorite to do the sanitizing. Once again,
check temperatures with a thermometer,
and make the necessary adjustments.
Use cleaning materials
that save hot water
In washing, your objective is to get
things clean. This may require little if
any hot water, since cleaning materials
are now available that will perform satisfactorily with less hot water than you
may have been using. Some of these
cleaning materials still require hot water
for washing hut need less rinsing or may
be used with cool rinses.
Maintain the right
dishwasher water pressure
Too little pressure means dishes and
utensils may not get clean. Too much
pressure can waste hot water; you may
need an inexpensive pressure reducing
valve to correct this.
after the power is off, and a wetting
agent added to the rinse water may
eliminate the need to do power drying.
Invest in a heat recovery system
A good wastewater heat recovery system
can he an excellent investment for your
laundry or dishwashers. (See p . 47 for
more information, diagram.)
Heat recovery is possible for drying
operations, too. Dryer exhaust air may
he 150’ to 190’ in temperature; when it
is vented to the outside, this heat is lost.
Heat recovery systems can be installed
to re-use some of this heat. There are
two basic types: heat exchangers (rotary
and stationary types) which transfer the
heat from the exhaust air to the supply
air without mixing the two; and dryer
exhaust recirculation systems which
reintroduce into the dryer some exhaust
air which still has capacity to absorb additional moisture. Both types of systems
can save energy and may have relatively
short payback periods; which type is
better often depends on the size of your
drying operation.
Use equipment more efficiently
This means loading washing machines
and dryers fully rather than running
partial loads, and spacing tableware
closely if a conveyor system is used.
Don’t run a dryer longer than necessary;
for dishes, the residual heat in the
machine will continue to dry the dishes
Buy energy eficient equipment
Two examples of machines with energysaving controls are shown below.
Reduce water temperatures
as much as possible
Laundry water temperatures should
he reduced to 160’ unless codes require
higher settings. If you can use soaps or
detergents that will work in cooler
water, you may be able to use even
lower temperature settings. Water
heaters that supply hot laundry water
may have an adjustment knob with
“high” and “low” settings. Check the
temperature at the washing machine
with an accurate thermometer, and
make the necessary adjustments.
Dishwashers usually use wash water
at 140”and rinse water at 180” (using a
booster heater) to sanitize and meet
Microcomputer in new clothes dryer permits
precise temperature and time control. Machine
also has internal heat reclamation device.
Microcomputer on newer model clothes
washing machine permits precise control
of water temperatures, cycles.
57
Swimming Pools
A heated swimming pool can use a lot
of energy to heat the water and to operate the filter system pump. The more
days per year your pool is operational,
the more energy dollars you use-and
the more you can save. Here's how:
Prevent loss of pool heat,
and improve water heating
efficiency
Even if warmed only a few degrees, the
massive amount of water in a heated pool
can require a lot of energy to reach and
stay at the desired temperature. There are
several ways to reduce the amount of purchased energy used by your pool:
Use a pool cover
A plastic cover on your pool when it is
not in use may be your best investment.
It can lower pool heating costs as much
as 50% and also reduce water evaporation and chemical costs. In warmer
months, the heating system may hardly
ever be needed: a cover can keep nighttime heat loss to just 1" or 2" instead of
4 O or 5", and in an outdoor pool the sun's
warmth can be absorbed through the
cover if the pool is kept covered during
those parts of the day when it is not
needed for swimming.
Install a more eficient heater
The difference between the efficiency of
your present water heater and one of the
new high efficiency models may be
great enough to justify your replacing
your present heater even if it still has
years of useful life left. If it clearly
needs replacement, you should definitely replace it with a high efficiency unit.
A heat pump water heater may be
your best bet, since it is very efficient.
A solar heating system may also be
something to consider, as well as a heat
reclamation system drawing on waste
heat from a laundry, your air conditioning or your space conditioning heat
pump (in air conditioning mode), or
some other on-site source (see pg. 50).
L / I / / i
A plastic cover may be the best investment for your pool.
For an indoor pool, a dehumidifying
heat pump pool heater should be considered: it will maintain the proper pool
temperature, air temperature, and
humidity levels, reduce the corrosive
effects of pool chemicals, recapture heat
from the air, and eliminate the need for
energy-wasting high ventilation rates.
Reduce hours of operation
of the filter system pump;
get a more efficient pump
Reduce the time
the filter system is on
If the pool is lightly used, the filter system may need to be run only four to five
hours a day in the summer, even less in
the winter, cutting pump electricity use
by perhaps 50% or more. Even heavier
use may require only eight hours of filter-
ing. Consult local authorities as to what
would be best for your particular pool to
keep it an attractive and healthy facility.
If the water can be kept clear and
properly balanced chemically with
fewer hours of pump operation, lots of
energy dollars can be saved. Table 21
shows representative savings for a pool
used 365 days a year. As you can see, for
such a pool $500 to $1,000 or more can
be saved annually just by making sure
the filter system doesn't run all night.
You may want to have a time clock
installed to make sure the reduced
pumping schedule is followed.
Buy a more efficient
replacement motor
If the pool pump motor needs to be
replaced, buy a high efficiency one of
the proper size (see next page).
~~~~
Table 19
Annual Savings from Reducing Running Time
of a Swimming Pool Filter Pump*
Your electricity
cost per kWh:
Your savings if the operation of a 2 hp pump*'
is reduced by this number of hours:
2
4
6
8
$ 84
118
151
185
216
252
286
320
1%
$168
235
302
369
437
504
571
638
$252
353
453
554
655
756
857
958
$336
4 70
604
739
873
1,007
1,141
1,275
12
16
$504
705
907
1,108
1,310
1,511
1,712
1,913
$672
940
1,209
1,478
1,746
2,015
2,283
2,551
' Assumes 365 davs Der veal of DOOI
owation: multiolv bv Dercentaae of vear your DOOI is used.
*' For a larger or smalier pump, these figures may NOT simpiy be increased or decreased accordingly, since there is no linear correlation between
pump Size and energy use. Consult an expert for figures for other hp pumps. Adapted from Southern California Edison source materials.
58
MACHINES
Electric Motors
rectly (over-sized or under-sized units
will operate at reduced efficiencies). In
many cases, motors were sized conservatively (Le., over-sized) in the original
design and can now be replaced with
units with lower horsepower ratings.
Obviously, any new motor, whether
or not it is a replacement, should be the
right size for the intended use. In general, you should have a professional determine the appropriate motor size.
Consider a high efficiency motor
Electric motors account for about three
quarters of total electricity use in industry and half of the electricity use in
commercial and institutional buildings.
You may have electric motors in HVAC
and refrigeration systems, elevators,
conveyor belts, printing presses, blowers, pumps, and a wide variety of manufacturing and assembly equipment.
Motors in new equipment
Check any electric-driven equipment you are considering buying
When buying a piece of equipment powered by an electric motor, be sure
the motor has a high efficiency rating.
Replacing a Motor
You may have to replace a motor
because it has burned out (and you
decide not to have it rewound-see
below) or because of a renovation or
expansion project.
You may also choose to replace an
existing motor that still operates well,
because a more efficient one may be a
very good investment and can save you
money every year on your electric bills
(see example, p.60). Your payback will
depend on your electric rates and how
many hours you run the motor.
Buy the right size
When replacing a motor, the first step is
to verify that the old one was sized cor-
New motors are available in standard
and high efficiency models. A high-efficiency motor will cost more than a standard one, but electricity savings can
quickly pay back this cost difference if
the motor is used a lot. (But also see
“Note, ” on next page).
Rewinding a burned out motor often
reduces its efficiency. When energy costs
are considered, it is often a better investment to buy a new high efficiency motor.
How can you tell how efficient
different motors are? To describe their
most efficient motors, different manufacturers may use the adjective “high,”
“premium,” “super,” or “extra.” But you
need precise information in order to
make your purchasing decisions.
Fortunately, there is something called
a nominal efficiency rating, which indicates a motor’s score on a standard performance test. The test, the rating system, and the standard, referred to
as IEEE 112B, were developed by the
Institute of Electrical and Electronics
Engineers (IEEE).
Table 20 shows average nominal efficiencies for standard motors and
for “energy efficient” motors of different
horsepower ratings. The higher the
number, the more efficient the motor.
You will find on the market motors with
higher nominal efficiencies than the
averages shown; look for them.
Table 20
Electric Motor Efficiencies
(IEEE 1128)
Average
Nominal Efficiency
-
Motor
Horsepower
Rating
~~
1
1.5
2
3
5
7.5
10
15
20
25
30
40
50
60
75
100
Standard
Motor
~
~~
73.0%
75.0
77.0
80.0
82.0
84.0
85.0
86.0
87.5
88.0
88.5
89.5
90.0
90.5
91 .o
91.5
59
Efficient
Motor
~
83.0%
83.0
83.0
86.0
87.0
88.0
89.0
90.0
90.5
91.5
92.0
92.5
93.0
93.0
93.5
94.0
When you shop, check each motor’s
nameplate for its nominal efficiency rating. If you don’t see it, you should
drop that motor from consideration.
How to compare motors. In addition
to the horsepower rating (hp) and the
nominal efficiency of each motor, you
will need estimates of how hard the
motor will have to work (its mechanical
load) and how many hours pcr year it
will run. The example on page 60 shows
that careful attention to efficiency ratings can result in hundreds of dollars a
year in energy savings for a 20hp motor
that runs continuously. The payback of
the extra cost for the higher efficiency
motor can be very fast.
MACHINES
NOTE: High efficiency motors usually run somewhat faster than their standard counterparts. When powering
loads such as fans or pumps the higher
speed can result in an increase in energy use. To avoid this, when replacing a
standard motor with a high efficiency
one, care must be taken to match RPMs
as closely as possible and/or compensate
for the increased speed by adjusting fan
sheaves or trimming pump impellers.
Variable speed drives and other
options. Most of the time, in the operation of your HVAC system you don’t
need the full power that its motors can
produce. Similarly, there are industrial
processes, like grinding, where precise
speed control or different levels of
motor power output are needed.
To get the motor power output that’s
required, you have three options. The
first is “throttling,”which lets the motor
continue to run at full speed but chokes
off some of its power output. Throttling
wastes energy; although widely used in
HVAC systems, it is not a desirable option.
Rather, you should consider equipping the motor with a variable speed
drive, which will allow the motor to run
at less than full speed. The savings
potentials from variable speed drives
in many facilities far exceeds the savings from high efficiency motors. Be
sure to consider VSDs.
In some situations, especially in hot
water distribution for an HVAC system,
the correct solution will be the third
option, using several smaller motors
that can be run individually or ganged
to meet the varying needs of the system.
Get the advice of an expert, particularly if you are presently throttling.
Example of a Motor Efficiency Comparison
Motor rating:
Mechanical load:
Use schedule:
20 hp
85% of rating
24 hrs/day, all year = 8760 hrslyr
Motor A
Motor B
“Standard”
20
87‘/o
“Premium”
20
+ nominal efficiency
20 h p
x 85%
x.746*
+87%
20 h p
x load
x kW/hp
= kW used/hr
14.58 kW
13.94 kW
Savings per hour:
.64kW
Horsepower
Nominal efficiency
91 %
Electricity use/hr :
Horsepower
x 85%
x.746*
t91%
Difference in electricity use per year:
.64 kW
Electricity saved per hour
x 8,760 hrs/yr
x hours used/year
= electricity savedlyr
5,606kWh
Annual savings** in electricity costs 0 various rates/kWh:
5e
7e
9e
Ilt
1%
15C
17C
1%
$280
$392
$505
$617
$729
$841
$953
$1,065
’ ,746 kWihp is the conversion factor from horsepower to kilowatts
*’
Example: 5,606 kWh x .09 = $504.54
Industrial Processes
If you are involved in manufacturing,
fabrication or processing of materials,
assembly, packaging, or some other
“industrial” activity, energy can be a
most important cost of production. Most
industrial machines and equipment are
used in processes that require heat, hot
water, cooling, pressure, or movement.
There are so many different industrial processes and types of energy-using
equipment that the subject is really
beyond the scope of this guide.
However, there are several important
subjects that should be covered.
Improve electric motor
efficiency
Motors are involved in so many operations, and can be such a large energy
user, that you should make every effort
to control their energy use. Be sure to
thoroughly review the motors section.
Operate and modify
machines for efficiency
Check the “12 Basic Rules” on p. 52.
They apply to many different types of
machines. In addition to paying atten-
60
tion to operating practices, adjusting
and modifying the machine can really
make a difference (and may be quite
inexpensive to do), as the following
example shows.
Example: the air compressor.
As an illustration of how machine
energy use can be reduced, let’s look
at one commonly found piece of equipment, the air compressor.
Many automotive businesses and industries use compressed air. Like your
hot water system, your compressed air
MACHINES
system may be costing you energy dollars in the form of “stand-by” losseskeeping air under pressure when it’s not
needed -or by leaking at various points
in the system. Or you may be running it
more than you need to.
Turn off the
compressor whenever possible
Fix leaks in hose connections, shutoff
valves, pipe connections and flanges,
in hoses and clamps, and in worn air
cylinders. Your best chance of detecting
leaks is when noise levels in the area are
low-after work, at lunch, or during a coffee break. Many leaks can be fixed easily
and inexpensively by repairing seals or
replacing gaskets or hoses. Particularly in
high pressure systems, letting a leak continue can be very expensive.
rior wall, the compressor will be able to
use cool outside air, which takes less
energy to compress.
Select replacement
equipment for
increased productivity,
energy savings
For energy savings, sometimes equipment modifications or adjustments will
do the trick, other times the equipment
will need to be replaced. Equipment replacement may be justified by energy
savings alone, but often the major reason to get new machines will be to add
new capabilities or to increase production capacity (fortunately, the innovations in equipment design that boost
output may be coupled with energy efficiency improvements that result in
lower energy use per unit of product).
Whenever you look to replace your
equipment, be sure to explore the energy efficiency of the new units.
Find out more about
your own processes
and equipment
Air compressor vented to outside.
Use the right nozzles
If you use compressed air to clean or
blow away excess material in the manufacturing of a product, make sure you
use a nozzle that concentrates and controls the stream of air. Using a hose
without a nozzle, or a nozzle with
too large an opening, will waste lots of
compressed air-and energy dollars.
Engineered nozzles and fittings can be
bought at low cost.
Use outside air
Many air compressors are located in
boiler rooms or mechanical rooms and
must compress warm inside air. If you
install an outside air intake in the exte-
Your trade association and possibly
your utility will have more information
on energy saving techniques. Among
the national trade associations which
have developed industry-specific energy
management information are the following: the Hardwood Plywood Manufacturers Association, the National Frozen
Food Association, and the Society of the
Plastics Industry.
efficiency by getting more useful energy
output from the fuels or electricity you
purchase.
More about heat recovery
Heat recovery or reclamation systems
capture heat that otherwise would be
lost-from used domestic hot water, an
industrial process, lighting, a computer
installation, or HVAC equipment-and
use that heat for some other purpose.
A typical waste heat reclamation installation is for a dishwashing operation, where heat from waste dishwasher
hot water is used to pre-heat fresh water
coming into the system (a water-to-water
heat exchange-see diagram, p . 50).
Other forms of heat recovery besides
water-to-water include: air-to-air, where
exhaust air is used to help heat incoming air; air-to-liquid,where the exhaust
air is used to heat water; refrigerant-toair or liquid, where the hot refrigerant
gas is used to heat air or liquid; and
waste combustion heat (e.g., from a boiler) which can be used to make steam or
to heat air or water.
Should you invest? If your industrial
process throws off a lot of heat,
installing a heat recovery system is definitely something to explore with an
expert. While it usually requires some
investment, it can provide an excellent
financial return.
Explore “free” energy
The idea of “free” energy is uniquely
appealing. It usually isn’t really free,
however, since to put the energy to work
requires investment in equipment that
will capture or recapture it, and then
“deliver” it in a useful form.
Solar, wind, and geothermal energy
sources are deservedly gaining more
attention and wider understanding. But
perhaps a subject of more immediate
value to you is heat reclamation, which
allows you to achieve greater energy
61
Machines
Take a look a t your machines
and equipment, using the conve nient “w a Ik-t hroug h ”
self-audit form on p.65.
Things to Do
CHECKOUT
YOUR BUILDING
Doing a "Walk-Through Self-Audit"
A walk-through self-audit will give you much of the information you need to start your energy management program. Get expert help with the walk-through if you need it.
Duplicate these pages
Ideas for your Energy Action Plan
If you need to, make extra copies of these pages so you
will have enough for all areas of your space or building
and for all machines and equipment.
Jot down the things you want to do in each area, and put
your top priority projects in your Energy Action Plan (p.72).
Lighting
For each area, inside and out, you will
need the following information:
Existing lights and controls
dayslyear
Lights are on:
hoursjday
Can lights be switched on and off as desired: -
Location of lights:
Additional hours lights could be turned off
hours per day
hours per week
Type of fixtures:
Is there an automatic timer?
Is it set properly?
Number of fixtures:
Number of lamps per fixture:
Type of lamp (brand, wattage, specific designation or code):
To calculate lighting savings
Watts per ballast:
Watts per fixture:
Square feet in area:
S e e t h e tables in the lighting section.
Total watts in area:
Watts per sq./ft.:
Present light levels: Too bright-Adequate-Too
Footcandle level*:
Energy Action Plan Ideas
dim-
footcandles
*measured at surface where light is needed (exit light
footcandles measured at floor level)
62
SELF-AUDIT
Envelope
Outside
Inside
For each area (e.9. front of building):
Insulation
Are there storm or thermal windows?
Check if NOT
Location Insulated
O Yes
ONo
Present Insulation
Thickness
Tvpe
Ceiling
Walls
Describe:
Floor
~~
NumberAocation of broken or cracked windows
Location of drafts (use tissue to locate):
Description of door or window repairs or replacements
needed (including door closers):
Caulking:
Location of windows that need shades,blinds or reflective film:
feet to replace
Weatherstripping:
feet to install
feet to replace
Energy Action Plan Ideas
feet to install
Loading docks and garage doors in need of improvement:
Hot Water System
System Components
Showerheads, Faucets, Other
Type of water heater, energy used:
Showerheads: Rate of flow:
Average use/day:
Tank storage capacity:
Faucets: Rate of flow:
Dishwasher: Capacity:
gallons
gallons/hour
Recovery rate:
Temperature setting:
Times used/week:
Washing Machine: Capacity:
"F
Make, model, age:
Length of uninsulated distribution piping:
Energy Action Plan Ideas
feet
Hot Water Temperatures
At showerhead:
"F At faucet nearest tank:
At dishwasher:
OF
At washing machine:
I:
~
gallondminute
minutes/shower
gallons/minute
gallons
gallons;
times used/week:
Have cool water washing materials been tried?
Tank insulation:
Location, description of other heaters, if any: -
At other location: (
~
"F
"F
O F
63
SELF-AUDIT
C System
Air Conditioning
Controls/Use
Number of units:
Location(s) and description(s) of thermostats:
Make, type, size, location of each:
Location(s) of thermostat(s) that might need
to be locked:
Frequency of service:
Date of last service:
Location of clock thermostat:
Cold weather thermostat setting:
Heat Pumps
Number of units:
Make, type, size, location of each:
OF
When, how much thermostat is set back:
for the weekend:
for the night:
Hot weather thermostat setting:
OF
Do they have auxiliary heating?
When, how much thermostat is set back:
for the weekend:
for the night:
If so, do they have controls minimizing use of that heating?
How many hours a week is system used?
hours in hot weather
hours in cold weather
Frequency of service:
~
Date of last service:
~
Can system be turned down during cleaning hours?
Central Heating Plant and System
~
Location:
When is system turned on/off in relation to daily occupancy (i.e., before, after, by how long)?
Type of fuel used:
Type of system (e.g., hot water, steam, warm air):
Which areas are too hot, too cold?
Number of zones:
Age of boiler or furnace:
Age of burner:
psi) or hot water temperature(
Steam pressure I
Calculating Your Savings
The tables in the text will help you estimate some savings, while for others you may need help from dealers or
manufacturers or from energy consultants or your utility.
OF).
If you have a steam system, when were steam traps last
checked?
Type, condition of insulation on boiler:
Energy Action Plan Ideas
Type, condition of insulation on air ducts or on distribution piping:
Is domestic hot water heated by the boiler?
Frequency of testing/cleaning adjustment:
Date of last test/service:
Results of test (e.g., combustion efficiency YO):
Has HVAC system been “balanced?”
64
SELF-AUDIT
Machines and Equipment
For each machine or piece of equipment:
Office Machines
Swimming Pool
Size of pool:
Machine type, location:
Type of water heater:
Wattage (nameplate watts, or amps x volts): -
Rating (kW or BTU/hr):
Filter pump motor hp and efficiency rating:
Capacity:
gallons
x 30%=watts of energy to operate it:
Is it left on overnight?
over weekends?
H o u d w e e k filter pump is operated:
Hourdweek operation could be reduced:
Daily hours of operation:
Hours per day it could be turned off
Hours pool is covered:
Motors
Size of motor
Refrigeration and Freezing
Type, age, energy used:
Compressor rating:
hp; age:
hp; age:
years
Hours of operation per day:
years
Is it turned off when possible?
What is its efficiency rating?
Type of power output reduction used, if any (variable
Present temperature OF:
Are cases overloaded?
Are night covers used?
speed drive or throttling)
Do doors close completely, by themselves?
Industrial and Shop Equipment
Cooking
Type, age, energy used
Temperature now used:
Function of machine:
Energy rating (e.g. watts or hp):
OF
Hours used/day :
Is this the lowest possible temperature?
Possible modifications in its use:
Is equipment turned off when possible?
Could it be shifted off-peak?
Are there exhaust hoods?
Air Compressors
Pressure setting:
Washing and Drying
Type, age, energy used:
Temperature now used:
psi Age:
Is it turned off when possible?
"F
Location of leaks:
Have you tried to reduce stand-by losses? (see Hot Water
Is outside air used?
section)
Are machines fully and properly loaded?
Energy Action Plan Ideas
Are low temperature cleaning materials used?
Heat Reclamation
Description of present system, if any:
Potential for a system (waste water, exhaust air, or other):
65
Rating:
hp
MAKE OPERATION
& MAINTENANCE
WORK FOR YOU
Timely adjustments will
save you energy dollars
Preventive maintenance
extends equipment life
Tuning up your oil burner after the heating season has started
will cost you energy dollars. So will adjusting your outside
light timer ufter daylight saving has started, or checking the
settings o n your air conditioner thermostats weeks ufter the
warm weather has set in.
Doing those important energy-saving things at the right
time-the right time during the year, week, or day-will save
you the most energy dollars.
Equipment operates more efficiently and uses less energy
when properly maintained. But timely maintenance also
extends the useful life of equipment, reduces the cost of
repairs, and prevents breakdowns which generally happen at
the worst possible time. Use the schedules on this page, but
also follow manufacturers’ maintenance suggestions. If your
owner’s guide is missing, contact the manufacturer with the
model number, or call a local repair service for recommendations.
What to Do When
SEASONALLY
WEEKLY
DAILY
At beginning of heating season:
Inspect, test, and tune up heating
system-adjust, replace filters,
nozzle or other parts
Turn off heating in unoccupied areas
Check thermostat accuracy
Adjust thermostats for desired
heating levels
Cover window air conditioners
At beginning of weekend or other
closed period:
Set back thermostats for heating or
air conditioning
Turn off all lights except safety
and security lights
Turn off water heater (if closed two
or more days)
Check any automatic HVAC
controls for accuracy of settings
At beginning of day:
Turn off outside safety/security lights
At beginning of cooling season:
Inspect, test, clean air conditioning
system
Turn off air conditioning in
unoccupied areas
Adjust thermostats for desired
cooling levels
Adjust outdoor light timers for
length of day and/or daylight saving
At end of cooling season:
Caulk, weatherstrip, fix doors and
windows
Inspect, test, clean air conditioning
system if used year-round
I
I
Timer inside clock thermostat, set to
change temperatures at 9 am and 4 pm.
During partial occupancy early in day:
Use only necessary lighting, heating,
air conditioning
During full operating hours:
Adjust thermostats for desired
heating or air conditioning levels
one-half hour after opening, if
comfortable for occupants
Turn off lights where daylight is sufEcient
Turn off lights when areas are not occupied
Adjust heating, cooling levels for comfort
Keep doors and windows closed to
prevent energy loss
Set back thermostats for heating or air
Conditioning onehalf hour before closing
During cleaning or partial occupancy
at end of day:
Use only necessary lighting,
heating, air conditioning
At closing:
Turn off all lights except safety and
security lights
In hot season, admit night air if it
will cool building
When daylight saving starts and ends:
Adjust outdoor light timers for
length of day
66
EE M S
CONSIDER AN
Stand alone EMS
controlling one
machine
(Energy Management System)
units, industrial equipment, etc.) when predetermined peak
load limits are approached. This will save money in demand
charges on your electricity bill.
It can also analyze outside and inside temperatures and turn
the HVAC system on or off for optimum energy efficiency and
comfort, or select the most efficient combinations of HVAC
equipment to satisfy building loads at any time. Some systems
will also implement safety procedures such as sounding alarms
and turning on exhaust fans when smoke is detected.
Think of how many times people forget to turn something off
at night, and how inconvenient if not impossible it is during
operating hours to adjust all the controls that would make
things operate at highest energy efficiency or save you the
most dollars on your energy bills.
Consider an EMS, the coordinated,
centralized control that can save $$
An energy management system (EMS) can be a fairly simple
“stand-alone”unit connected to one or two pieces of equipment, such as a heat pump or rooftop HVAC unit. Or an EMS
might be a more extensive system which controls lights and
equipment throughout your facility.
Whether large or small, an EMS consists of: a computer;
software to create an energy management program and schedules; sensors and controls located where needed; and, in a larger EMS, a communications network. A stand-alone EMS can
look like a box with a numerical window display; a larger system
would have a full computer terminal and color video display.
You will recognize many of the functions from among the
energy efficiency operational measures discussed earlier. The
EMS simply takes over these functions and performs them more
reliably and precisely than you might be able to manage manually.
Monitor your EMS operation
Your EMS can substitute for you, but not entirely. Monitor it
regularly, to make sure it is doing what you want it to do. Also,
be sure to change its settings or program instructions to reflect
new hours or any other operational changes you may make.
Rapid payback, lower costs-and
needn’t have a large building
you
If you operate a few pieces of equipment that use a lot of energy, consider a stand-alone EMS. If you want to control all your
energy uses automatically, including your lighting, or if you
just have a lot of energy using equipment, an EMS with a network would be your choice.
Small and large energy management systems can save
10-20% on kWh energy charges, depending on your mix of
equipment, and can reduce your demand charges as well. They
can deliver simple paybacks of two to four years; larger systems have substantially greater capabilities to cut your demand
charges, which in some cases might shorten this payback time.
Advances in computer and microprocessor technologies are
rapidly driving down prices, while increasing EMS capabilities, and you should be considering an EMS with the help of a
knowledgeable expert even if you have a smaller facility.
Doing jobs you can’t do
An EMS can also perform functions that cannot be carried out
manually. In particular, it can monitor total building loads and
turn off appropriate pieces of equipment (water heaters, AIC
What an EMS Can Do
Intel!igently programmed to meet your needs, an EMS can
automatically and reliably remember to:
turn off lights in unoccupied areas
maintain partial lighting before and after “public” hours
EMS controlling many functions
with sensors/controls
assure that only necessary safety and security lighting is on
schedule lighting operation by hour of day, and time-of-year
turn off a water heater when appropriate
eliminate hot water circulation when an area is unoccupied
maintain HVAC system start-up and set-back schedules
eliminate unnecessary HVAC use during unoccupied hours
run swimming pool filtering systems only during hours
you have chosen
numerous other functions
67
SAVE WHEN YOU
BUILD
Key Energy Points for Your New Building or Build-Out
Whether yours is a large construction project or a build-out of a
modest amount of space, you have lots of opportunities to maximize energy efficiency and keep your energy costs down. There
are two main advantages of “starting from scratch.” First, you
are free to select the most energy efficient system designs and
products on the market. Secondly, and perhaps more important,
you can design your space or building to minimize its energy
requirements-by using daylighting and other techniques in
lighting design, and by reducing heating and cooling loads so
that smaller HVAC units may be used.
Looking at a Build-Out
The build-out includes the following:
off-white walls and ceilings to reflect light
3-lamp ceiling fixtures, with 32-watt T-8 lamps and
electronic ballasts
switches to control lights in each office and work area
additional switches to control fixtures nearest windows
ceiling fixtures located over work surfaces
large panels of glass on interior office walls to allow
office lighting to spill into interior spaces
15-watt compact fluorescents in reception area down
lights, a total of 105 watts in that ceiling (1/3 watt sq.ft.)
a single 15-watt compact for the front door sign
a %watt task light for the drafting table
caulking around window frames
Double glazed windows had already been installed.
Except for the task light, all the rest of the energy efficiency
features were provided by the landlord at no cost to the tenant.
When selecting and subdividing (or “building out”) an open
area, careful attention to the choice of space, layout design,
and energy installations can make a significant difference in
energy use.
In this rental suite of offices, the tenant pays for electricity for lighting, for air conditioning (distribution only), and
for machine use.
The raw space chosen for the suite is on a middle floor
on the north side of the office building, sheltered on the
east and west by other buildings, a location with minimal
heat gain from the roof and sun. The layout capitalizes on
the perimeter windows on all three sides for natural lighting; reception and storage areas are in the interior.
Installed lighting totals just over one watt per square foot
of floor area (the tenant’s previous space in the same building had more than two watts per square foot).
Results of careful energy design:
It is estimated that energy use is half what
it would have been if the lighting had been like
that in the old space and the new location had
not been carefully chosen for protection from
solar gain.
68
SAVE WHEN YOU BUILD
When you’re building or adding on
Also, remember that while your state or local codes
may require certain kinds of equipment ( e g , self-closing
valves on lavatory faucets) or types of construction (e.g.,
minimum insulation) that will reduce energy consumption,
you can achieve even greater energy savings by “going
beyond code.”
When you add on or construct a new building, you are making a fresh start, and it will pay you very well to review construction specifications, orientation, design, layout, lighting,
equipment, and control selections. By designing and selecting
wisely, at little or no extra cost you may be able to keep future
energy bills 30-50% lower than they otherwise would have been.
Check your plans for these
Not too many lights; enough daylight
Energy efficient hot water system
Enough light switches for flexibility in controlling lights
Water heater near main point of use
Efficient fixtures and lamps, appropriate for your needs
Hot water pipes insulated
Energy efficient fluorescents and ballasts; few, if any,
Low flow showerheads, energy efficient faucet controls
incandescents
High pressure sodium parking lot lights; efficient exit signs
An efficient HVAC system, with enough zones, flexibility
Timers or photoelectric controls for indoorloutdoor lighting
Occupancy sensors
Use of heat pumps, if appropriate
Excellent HVAC controls for all zones, weather conditions
Efficient glazing system for reduced heat gain and
Programmable thermostats, that go down to 50°
increased daylight penetration
HVAC pipes or ducts insulated
Heating, ventilating, air conditioning not oversized
Sufficient insulation for roofs and walls
Multi-story building design, if possible, for HVAC economy
Light colors, both inside and out
Exhaust fans in rest rooms wired in tandem with lights
Use of land slope, trees to shield building from winds;
Adequate wiring for area heaters for remote locations
building recessed in slope for insulation, if appropriate
Cool storage system to reduce peak loads and utilize
Overhangs to shield windows from sun
lower off-peak rates
Thermal windows; adjustable shades, blinds, or
reflective film
Solar space andlor water heating, if appropriate
Windows that can be opened, if appropriate for your climate
Energy efficient machines and equipment
Caulking and weatherstripping
An EMS (energy management system) for optimum
Entrance vestibules with revolving or double sets of doors
energy control
Achieving even greater energy savings by “going beyond code.”
Designed for super savings: (left to right) new office building, supermarket, and credit union. Actual energy consumption has been measured at
20-30% less than if these buildings had been constructed to the energy-conserving standards of applicable codes.
Courtesy of the Energy Edge Project, Booneville Power Administration
69
EXPLORE WAYS TO
REDUCE Y O U R
ELECTRIC BILLS
This is a brief explanation of an important subject. If you want
to know more about changes you can make that can save you
money on your electric bills, get in touch with your electric
utility representative.
How your utility charges for electricity
There are three basic types of charges that you may see on your
electric bills:
kilowatt hour (kWh) charges, which cover the total amount
of electricity used during the billing period. The kWh
charges may be at a flat rate, or at a declining block rate (the
more you use, the less each kWh costs);
fuel adjustment charges, for increases in fuel costs (the oil
or other fuel your utility may buy to generate the electricity)
over some base level, usually added at a flat rate per
kilowatt hour; and
demand charges, for the greatest amount of electrical power
(in kilowatts, kW) supplied to you by your electric utility.
Demand charges are the way your utility pays for maintaining
the excess capacity it must have to meet peak demands that
occur from time to time. The demand charge you pay is calculated on the basis of your highest demand over a short period
of time (usually 15 to 30 minutes) during the past month. Your
utility then assumes that, during the following month, you are
likely to need that amount of peak power again, at some undetermined time, and bills you accordingly for the cost of maintaining extra generating capacity so it can meet your demand
at any time during the entire month. Some utilities have a
“demand ratchet” that sets your demand charge for the entire
year on the basis of the highest demand during a single month,
even though you never approach that level of demand at any
other time of the year. Your utility may also charge for high
demand on the basis of “hours use.”
rescheduling
Before reschedulinn
t o reduce
50
demand
charges.
5
% 40
m
f
30
:.m
20
n
Y
8
E IO
01
6AM
70
IOAM
2PM
6PM
IOPM
Y O U R ELECTRIC BILLS
Low Power Factor. It is unlikely,
but possible, that your facility has a
“low power factor”- that is, the equipment draws more in current (kVA) than
in power (kW).If the power factor is
below 80-90%, your electric utility may
be billing you extra. If this is so, ask
your utility for advice about what to do.
Alternative rates
Your utility may have alternative rates
which could save you money on your
electric bills. To take advantage of these,
you have to work out an agreement with
your utility representative.
First, there may be a flat rate which
is much higher per kilowatt hour but
when used eliminates the possibility
of demand charges. If your use of electricity is considerable but infrequent
(perhaps totaling less than 100 hours a
month), choosing a flat rate may save
you money.
If you can schedule much of your use
of electricity to occur during “off peak”
hours-evening, night or early morning-you may find there are lower time
of use (TOU) rates which would be to
your advantage. Rates may also vary by
season-for instance, electric rates may
be different in the heating season than
during the air conditioning season-but
you may have trouble doing seasonal
rescheduling of electric use to take
advantage of lower rates.
Finally, your operation may be flexible enough to allow you to use interruptible rates. Your electric utility, in
return for the right to require that you
reduce your use of electricity during
peak demand periods, may offer you a
rate which sharply reduces demand
charges or even eliminates them. If you
have high demand charges, interruptible
rates can save you a great deal. But you
have to carefully weigh possible disad-
electric energy consumption-total kWh
and kW used per month (your utility
may be able to supply the figures), how
much electricity is used at various
times, and the time changes or interruptions that would be convenient for you.
Any alternative rates your utility has
are advantageous to the utility as well,
because they encourage customers to
help the utility eliminate the expense
and inconvenience of maintaining
excess capacity. So you may expect your
utility representative to be quite helpful
in working out an agreement with you.
vantages. With interruptible service, a
utility representative will call you-perhaps only an hour ahead -and ask you
to shut down the equipment you have
agreed to shut down for the period of
time you have agreed on. If interrupting
your electricity use is too much of an
inconvenience for your facility, consider
purchasing an on-site generator which
can provide electricity during times you
have agreed to permit interruption.
Savings realized from interruptible rates
can often more than pay for a generator.
Call your utility for assistance.
To get an alternative rate, ask your
utility representative what is available.
When the two of you meet, you should
have with you information about your
Lowering your electric bills
If you now pay demand charges, can you reschedule the use of equipment?
List the possibilities:
Should you investigate alternative rates?
~
Other possible changes:
~~
Calculating Savings
Your utility can help you determine
savings on your electric bills by making various changes.
77
Action Plan Items
Include the most important changes
in your Energy Action Plan.
GET YOUR
ACTION PLAN
UNDER WAY
People to talk to
Schedule for your
(e.g., co-workers, maintenance staff, outside energy experts, utility people)
"walk-through" self-audit
Other notes
-
-~
-~
~
Dateflime
Dollar-Saving Energy Action Plan
Top Priority to Do
Location
Approximate Cost
(if any)
1.
2.
3.
4.
5.
6.
7.
8.
9.
IO.
72