EQC High-Efficiency Elite Plus Insert Wood Fuel

Energy. Intelligence.
LLC
Jerry Lewinson
(928) 478-4393
[email protected]
EQCEnergy.com
Environmental Engineering Services and Technology
EQC is…
Dedicated. EQC is continually researching the latest, state-of-the-art approaches to
water and wastewater treatment, including the improvement of air quality, and
energy efficiency.
Committed. EQC implements sustainable technologies that enhance the natural environment, provide healthy water, air, and land, and help transform polluted sites
into clean and productive contributors to a healthier planet.
Innovative. EQC designs, engineers, retrofits and improves water and wastewater systems for business, municipalities, property owners, project principals and consultants.
From bisolids waste management to water supply and treatment – EQC does it all.
EQC does…
Sustainable Environmental Solutions - Energy Intelligence Program (EIP)
Energy Intelligence Site Assessments; facilities to fleets, reveal savings opportunities
Fuel Combustion Optimization; reduce fuel consumption & emissions > EPA compliance
Monopole Fluid Treatment (water - fuels - refrigerants)
Water and Wastewater Management, Treatment, and Reuse
Water and Wastewater Treatment Plant Retrofits; mitigate
and resolve deficiencies, enhance treatment levels to EPA compliance
Optimization of Operating Budgets
Grey and Rainwater Harvesting and Recycling
Biosolids Waste Management; turning problems into assets
Industrial Wastewater and Process Water Treatment
Groundwater and Land Contamination Remediation
AZPDES Permits for Construction Pollution Issues
Hydrology, water resources management and bioremediation
Prevention and management of storm water, recycling and reuse of potable water,
and other green engineering techniques to support sustainable construction projects
Wastewater management and air pollution control,
Including recycling, waste disposal, industrial hygiene, environmental sustainability,
public health issues and studies on the environmental impact of proposed construction
projects.
Extreme Wildland fires in Arizona have been unusually intense due to fuel overgrowth and
difficulty implementing good land management practices. Experts fear that in the next 10
years we may lose half of our Ponderosa Stand due to out of control fires due to excess fuels
clogging up our forests. EQC supports the thinning and sustainable harvesting practices for
our forests. Fuel wood is the most easily accessible and affordable of all renewable energies,
and a high efficiency fireplace that attains nearly complete combustion can significantly
reduce your carbon footprint. Wood fuel is a matter of necessity, especially for those living in
Northern Arizona, to protect from freezing weather during power outages, and the best
alternative to rising propane costs.
Travis Industries engineers are the leaders in fuel combustion technology having developed
and patented the Fireplace Xtrordinair, which is the highest efficiency unit on the market that
has ever been tested by the EPA. EQC has become an exclusive representative for the
Xtrordinair system. The Fireplace Xtrordinair Elite features the Posi-Pressure system which
draws in “fresh air” from the outside, super-heats it, and quietly blows it into the home. This
has the effect of sealing any cold air leaks from windows, vents, doors and cracks allowing the
heat to travel throughout the home in a more efficient manner. As a result it will heat up to
3,000 square feet, rather than only the living room, with refreshing, “oxygen-rich air”.
Propane costs could reach $4-$5/gallon in the near future, and you may want to consider an
alternative plan for home heating, especially during power outages or emergencies with possible interruption of fuel supplies. Fireplace Xtrordinair Elite’s 92% combustion efficiency, will
give you peace of mind, knowing that you are no longer polluting and wasting 80% of the
heat from the cords of wood you are paying for, which is the case with a traditional fireplace
or stove. A real-world solution and a high-efficiency replacement for propane heating. See
for yourself at www.buildinggreen.com/calc/fuel_cost.cfm. Use 92% wood efficiency and $3
to $5 propane for the calculations.
Travis Industries recently won two VESTA 2011 awards from Hearth & Home Magazine for
the “Best in the Show” and the “Green Award” for its patented Lopi linetechnology that produces less than .5 grams of carbon/hr. It boasts 95% combustion efficiency. That’s almost
smokeless! No manufacturer can come close to that, their best is about 4 grams/hr.
Fireplace Xtrordinair Elite is featured in the April edition of Country’s Best Cabins magazine.
Please visit www.fpxproducts.com and www.lopiproducts.com to see all the Fireplace Xtrordinair high-performance systems; zone heating can provide energy savings of 20% to 40%,
and no duct work is required.
Let the experts at EQC show you the award-winning designs from Fireplace Xtrordinair and
how easy and affordable it is to own the very best protection for your home.
Nothing compares with a blazing hearth from Fireplace Xtrordinair and EQC to make
a home feel welcome, warm and cozy. Contact us to see our working models.
33 ELITE PLUS WOOD BURNING FIREPLACE INSERT
EPA Phase II
Approved
4.4
Grams/Hour
Maximum
Btu’s
Per Hour
73,300
Overall
Efficiency
83.5%
Heating
Capacity
1,200 to
2,000 Sq. Ft.*
Up To
10 Hour
Burn
Time
Accepts
Wood
Up To 24”
2.2
Cubic
Foot
Firebox
Heavy Gauge
Plate Steel
Construction
5/16” & 1/4”
33 ELITE PLUS WOOD BURNING FIREPLACE INSERT
Kiln-Fired
Masonry Lined
Firebox and
Baffle
Twin 90 CFM
Convection
Blowers
Standard
Installation
6” (153mm)
We suggest that you have an authorized Fireplace Xtrordinair dealer
install your fireplace insert. If you install the fireplace insert yourself, your
authorized dealer should review your installation plans.
28-7/8”
(734mm)
18-7/8”
(480mm)
The 33 Elite Plus Wood Insert is designed for installation in masonry
fireplaces and factory-built metal (Z.C.) fireplace. Check with your local
building officials for any permits required for installation of this fireplace
insert and notify your insurance company before proceeding with installation.
6-3/8”
(162mm)
19-3/4”
(502mm)
The 33 Elite Plus must be installed with either Positive Flue (full chimney
reline) or Direct Connect Flue (See Owner’s Manual for details).
21-1/2”
(547mm)
Testing
Tested and certified by Intertek Laboratories Inc.
Report #100289794PRT-001, Safety Tested to U. L. 1482 and ULC S628-93
10”
(254mm)
* Heating capacity may vary depending on degree of home insulation,
floor plan and ambient temperature zone of the area you live.
17-3/4”
(451mm)
1-1/4” (32mm)
Minimum Fireplace Size
A - Height (Front)
B - Height (Rear)
C - Width (Front)
D - Width (Rear)
E - Depth*
F - Hearth Depth
G - Hearth Width
Minimum Clearances to Combustibles
21-1/2”
19-3/4”
30-7/8” (includes 2” for power cord)
18-7/8” (Masonry) 20-7/8” (ZC)
17-3/4” (Masonry) 18-3/4” (ZC)
17-1/4” (US) 19-1/4 (CAN)
44-7/8”
* Add 1-1/4” * *
* when using
* one-piece panel
K - Sidewall To Insert 9”
L - Side To Facing 9”
M - Top Facing 39”
Designed to finish off the fireplace opening behind
the Shadowbox face. No Trim.
N
8” Single Piece Panel Set - 42” Wide x 30-1/2” Height
B
M
D
C
Shadowbox™ face
with concealed
convection grills
and single piece
surround panel.
Surround Panels for
Arched Door Insert
The three-piece surround panel designed to finish
off the fireplace opening. Surround panels can also
be custom cut to fit the inside dimensions of your
fireplace opening. These panels come with black
panel trim.
L
E
O
G
F
41-1/2”
6” US 8” CAN
16” US 18” CAN
Surround Panels for
Rectangular Door Insert
K
A
N - Mantle
O - Hearth (Side)
P - Hearth Depth
P
8” Panel Set - Covers 45-1/2” Wide x 29-1/2” Height
10” Panel Set - Covers 49-1/2” Wide x 31-1/2” Height
12” Panel Set - Covers 53-1/2” Wide x 33-1/2” Height
HEAT WITH THE ELITE PLUS
Turn Your Old Inefficient Fireplace Into A Reliable Source of Heat!
Burning wood in an open fireplace is just about the most inefficient way to heat your
home. In fact, you actually lose more heat up the chimney than you provide for your home. The
33 Elite Plus wood burning fireplace insert can convert your wasteful masonry or zero clearance
(metal) fireplace into a super-efficient heat source that can provide reliable heat at a fraction of
the cost of electricity or oil.
Visit us online: www.fireplacex.com
We reserve the right to improve our product at any time without prior notification • Photos and illustrations are for descriptive purposes only • Copyright © 2011/05
#98800213
33 ELITE PLUS WOOD BURNING FIREPLACE INSERT
For Rectangular Door Insert
Shadowbox™ face
with concealed
convection grills
and single piece
surround panel.
For Arched Door Insert
Efficient and Clean Burning!
Classic Arch™
gracefully
arched black
painted face.
The high-performance heat and exclusive flush-to-the fireplace design of the 33 Elite insert are truly out of the ordinary.
The single door of the unit comes in both arched and rectangular models and features a huge fire-viewing area of
250 square inches. The glass maintains its clarity and cleanliness thanks to our unobstructed air wash system.
Easy To Live With
Operation is as easy as a push of a button. A single air control allows you to set the fire to your desired setting. The 33
Elite is also one of the only wood burning inserts to feature a bypass damper that lets you open the flue before starting or
reloading your wood making fire start-up a snap and preventing smoke spillage into your home.
Fight Back On High Heating Bills!
Cut back on heating bills by burning wood, one of the oldest and still most efficient ways to heat your home. The clean
burning non-catalytic hearth technology found in the 33 Elite Plus is one of the most cost effective and dependable ways
to provide warmth to your home and save money on fuel.
The 33 Elite Plus is designed to deliver the
maximum heat from the wood you burn.
Using 1/4” thick plate steel and real masonry
firebrick lining in the firebox and baffle, the
unit maintains high operating temperatures
which not only allows for a very clean burn,
but also remarkable heat transfer. This heat
is evenly distributed throughout your home
using a five-sided convection chamber and
the standard twin 90 CFM convection fans.
The 33 Elite is designed to provide heat for
as long as 10 hours on a single load of wood
and heat up to 2,000 square feet. This clean,
green and ultra-efficient fireplace insert is
clean burning, non-catalytic, and boasts 83.5%
efficiency and an EPA certified 4.4 grams per hour.
American Made!
The 33 Elite Plus fireplace insert is premium
quality with a long lasting value. The insert
is American made and created out of only
the highest quality materials such as heavy
gauge steel (up to 5/16” thick), unibody
firebox, real masonry brick, one piece seamless
flue and stainless steel baffle and air tubes.
All of this contributes to the durability and
longevity of the product which is backed
by Fireplace Xtrordinair’s “Real World” Seven
Year warranty.
Classic Arch™
gracefully
arched black
painted face.
Artisan™
hand-forged,
hand-hammered
iron face.
Classic Arch™
black painted
face with optional
Arts & Crafts™
antique nickel
plated grills.
Classic Arch™
black painted
face with optional
French Country™
antique gold
plated grills.
33 ELITE PLUS WOOD BURNING FIREPLACE INSERT
For Rectangular Door Insert
Shadowbox™ face
with concealed
convection grills
and single piece
surround panel.
For Arched Door Insert
Efficient and Clean Burning!
Classic Arch™
gracefully
arched black
painted face.
The high-performance heat and exclusive flush-to-the fireplace design of the 33 Elite insert are truly out of the ordinary.
The single door of the unit comes in both arched and rectangular models and features a huge fire-viewing area of
250 square inches. The glass maintains its clarity and cleanliness thanks to our unobstructed air wash system.
Easy To Live With
Operation is as easy as a push of a button. A single air control allows you to set the fire to your desired setting. The 33
Elite is also one of the only wood burning inserts to feature a bypass damper that lets you open the flue before starting or
reloading your wood making fire start-up a snap and preventing smoke spillage into your home.
Fight Back On High Heating Bills!
Cut back on heating bills by burning wood, one of the oldest and still most efficient ways to heat your home. The clean
burning non-catalytic hearth technology found in the 33 Elite Plus is one of the most cost effective and dependable ways
to provide warmth to your home and save money on fuel.
The 33 Elite Plus is designed to deliver the
maximum heat from the wood you burn.
Using 1/4” thick plate steel and real masonry
firebrick lining in the firebox and baffle, the
unit maintains high operating temperatures
which not only allows for a very clean burn,
but also remarkable heat transfer. This heat
is evenly distributed throughout your home
using a five-sided convection chamber and
the standard twin 90 CFM convection fans.
The 33 Elite is designed to provide heat for
as long as 10 hours on a single load of wood
and heat up to 2,000 square feet. This clean,
green and ultra-efficient fireplace insert is
clean burning, non-catalytic, and boasts 83.5%
efficiency and an EPA certified 4.4 grams per hour.
American Made!
The 33 Elite Plus fireplace insert is premium
quality with a long lasting value. The insert
is American made and created out of only
the highest quality materials such as heavy
gauge steel (up to 5/16” thick), unibody
firebox, real masonry brick, one piece seamless
flue and stainless steel baffle and air tubes.
All of this contributes to the durability and
longevity of the product which is backed
by Fireplace Xtrordinair’s “Real World” Seven
Year warranty.
Classic Arch™
gracefully
arched black
painted face.
Artisan™
hand-forged,
hand-hammered
iron face.
Classic Arch™
black painted
face with optional
Arts & Crafts™
antique nickel
plated grills.
Classic Arch™
black painted
face with optional
French Country™
antique gold
plated grills.
33 ELITE PLUS WOOD BURNING FIREPLACE INSERT
EPA Phase II
Approved
4.4
Grams/Hour
Maximum
Btu’s
Per Hour
73,300
Overall
Efficiency
83.5%
Heating
Capacity
1,200 to
2,000 Sq. Ft.*
Up To
10 Hour
Burn
Time
Accepts
Wood
Up To 24”
2.2
Cubic
Foot
Firebox
Heavy Gauge
Plate Steel
Construction
5/16” & 1/4”
33 ELITE PLUS WOOD BURNING FIREPLACE INSERT
Kiln-Fired
Masonry Lined
Firebox and
Baffle
Twin 90 CFM
Convection
Blowers
Standard
Installation
6” (153mm)
We suggest that you have an authorized Fireplace Xtrordinair dealer
install your fireplace insert. If you install the fireplace insert yourself, your
authorized dealer should review your installation plans.
28-7/8”
(734mm)
18-7/8”
(480mm)
The 33 Elite Plus Wood Insert is designed for installation in masonry
fireplaces and factory-built metal (Z.C.) fireplace. Check with your local
building officials for any permits required for installation of this fireplace
insert and notify your insurance company before proceeding with installation.
6-3/8”
(162mm)
19-3/4”
(502mm)
The 33 Elite Plus must be installed with either Positive Flue (full chimney
reline) or Direct Connect Flue (See Owner’s Manual for details).
21-1/2”
(547mm)
Testing
Tested and certified by Intertek Laboratories Inc.
Report #100289794PRT-001, Safety Tested to U. L. 1482 and ULC S628-93
10”
(254mm)
* Heating capacity may vary depending on degree of home insulation,
floor plan and ambient temperature zone of the area you live.
17-3/4”
(451mm)
1-1/4” (32mm)
Minimum Fireplace Size
A - Height (Front)
B - Height (Rear)
C - Width (Front)
D - Width (Rear)
E - Depth*
F - Hearth Depth
G - Hearth Width
Minimum Clearances to Combustibles
21-1/2”
19-3/4”
30-7/8” (includes 2” for power cord)
18-7/8” (Masonry) 20-7/8” (ZC)
17-3/4” (Masonry) 18-3/4” (ZC)
17-1/4” (US) 19-1/4 (CAN)
44-7/8”
* Add 1-1/4” * *
* when using
* one-piece panel
K - Sidewall To Insert 9”
L - Side To Facing 9”
M - Top Facing 39”
Designed to finish off the fireplace opening behind
the Shadowbox face. No Trim.
N
8” Single Piece Panel Set - 42” Wide x 30-1/2” Height
B
M
D
C
Shadowbox™ face
with concealed
convection grills
and single piece
surround panel.
Surround Panels for
Arched Door Insert
The three-piece surround panel designed to finish
off the fireplace opening. Surround panels can also
be custom cut to fit the inside dimensions of your
fireplace opening. These panels come with black
panel trim.
L
E
O
G
F
41-1/2”
6” US 8” CAN
16” US 18” CAN
Surround Panels for
Rectangular Door Insert
K
A
N - Mantle
O - Hearth (Side)
P - Hearth Depth
P
8” Panel Set - Covers 45-1/2” Wide x 29-1/2” Height
10” Panel Set - Covers 49-1/2” Wide x 31-1/2” Height
12” Panel Set - Covers 53-1/2” Wide x 33-1/2” Height
HEAT WITH THE ELITE PLUS
Turn Your Old Inefficient Fireplace Into A Reliable Source of Heat!
Burning wood in an open fireplace is just about the most inefficient way to heat your
home. In fact, you actually lose more heat up the chimney than you provide for your home. The
33 Elite Plus wood burning fireplace insert can convert your wasteful masonry or zero clearance
(metal) fireplace into a super-efficient heat source that can provide reliable heat at a fraction of
the cost of electricity or oil.
Visit us online: www.fireplacex.com
We reserve the right to improve our product at any time without prior notification • Photos and illustrations are for descriptive purposes only • Copyright © 2011/05
#98800213
Editors Note: The following article is reprinted (with permission) from Home Energy
Magazine, which is an energy publication for professionals. It is somewhat technical,
but very readable and accurate.
As a member of the Industry for 17 years, I personally think that inefficient, open fireplaces SHOULD be against building codes. A building Inspector would refuse to approve
your house if you cut a one square foot hole in the wall and let your heated air escape,
but that's exactly what a fireplace does. We must move on from early "Americana" , and
just as we rid ourselves of the gas guzzlers, get rid of OPEN fireplaces that waste our
resources.
by A. C. S. Hayden
A. C. S. (Skip) Hayden is head of Energy Conservation Technology at the Combustion
and Carbonization Research Laboratory (CCRL) of CANMET in Ottowa, Canada.
Energy-efficient, environmentally-friendly, and safe alternatives to the outmoded
conventional fireplace are here, and they're aesthetically pleasing too.
Conventional fireplaces are incompatible with new, tighter housing, or with weatherized
homes because of their large air requirements and the incomplete combustion products
they produce. They can create significant indoor air quality problems and potentially
catastrophic situations in existing dwellings. Conventional fireplaces are also extremely
inefficient, sometimes even having negative energy efficiency. Most so-called solutions
attack only minor or isolated aspects of the problem.
New fireplace designs--specifically advanced-combustion wood fireplaces--offer an
alternative. Advanced fireplaces are attractive, comfort-supplying, and cost-effective
complements to conventional heating systems, even in tight homes. They can eliminate
indoor air quality problems caused by existing fireplaces, in a safe, energy-efficient and
environmentally benign way. They are also addressing what has been an extremely
challenging weatherization problem.
Myth versus Reality
Fireplaces have long been a staple of North American households. Builders find it
difficult to sell a new house without one. Yet the mythological attraction of cozy
fireplaces rarely translates into reality. Most fireplaces are difficult to start, smoke, create
unpleasant cold drafts, and cause a number of other unseen problems of which the
homeowner is often unaware. In most homes, conventional wood-burning fireplaces are
between -10% and +10% efficient. They supply little if any heat to the house, particularly
with cold outside temperatures.
How Wood Burns
If you take a close look at a burning log, you will notice something strange. In most
instances, fire appears only over a portion of the log. At the same time, smoke is coming
off, usually from a part of the log remote from the flame itself. This smoke is composed
of a complex mix of volatile incomplete combustion products that are being "boiled" or
distilled out of the wood before they can be burned. Without a means of igniting these
products and further burning them before they leave the combustion chamber, these
incomplete combustion products become creosote which can cause chimney fires, and
also turn into "particulates," which can be a major source of air pollution as well as
indoor air quality problems.
Efficiency
Field trials conducted by the Combustion and Carbonization Research Laboratory
(CCRL) of fireplaces in Canadian homes, in conjunction with other combustion
equipment, have shown that in all but one case, on cold winter days, use of conventional
masonry fireplaces actually resulted in an increase in fossil-fuel consumption for heating.
The fireplaces actually had a negative energy efficiency during the tests.
In the exception where a fireplace did reduce fossil-fuel consumption, the fireplace was
situated opposite from the house thermostat. Without glass doors, the fireplace's infrared
radiation fooled the thermostat into thinking the house temperature was satisfied, while
allowing the rest of the house to become quite cold. The owners had just arrived from
Great Britain and were used to cold bedrooms, so they thought nothing more about it.
The thermostat cutback did save energy, but the fireplace itself was still very inefficient.
Figure 1. Conventional fireplace schematic.
The low efficiencies of conventional fireplaces arise for a number of reasons, the most
important of which are:
·
High Excess Air. Excess air is the amount of air supplied for fuel combustion,
over and above that which is theoretically required. A typical oil or gas furnace
will require about 50% excess air for satisfactory performance. Conventional
fireplaces, on the other hand, operate at about 1500% excess air, 16 times the
theoretical requirement or more than 10 times what a fossil fuel furnace needs.
This translates into extremely high mass flows of air through the fireplace and up
the chimney when the fire is blazing.
·
In any combustion system, the greater the mass flow, the poorer the heat transfer
from the combustion gases to the system and the higher the sensible heat loss up
the chimney. Any combustion system operating at high excess air levels is
inherently inefficient. Table 1 shows the effect of excess air on a wood-burning
fireplace burning seasoned wood with a flue gas temperature of 300deg.F. At 100%
excess air, the sensible heat loss is 10% and the maximum possible efficiency the
system can have is 78%. Looking at a fireplace burning at 1500% excess air, the
sensible heat loss up the chimney is a huge 73%. The best efficiency a
·
conventional fireplace can have is only 15%. This does not even consider the
other inefficiencies and heat losses described below.
House Air Requirements. If a fireplace does not have its own dedicated outside
air supply and is not perfectly sealed from the house, under high excess-air
conditions, it will take up to 1.4 air changes per hour (ACH) of heated house air
and exhaust it up the chimney. If a fireplace were run continuously like this over
the entire heating season, this would increase the heating requirements of the
house by as much as 50%. Luckily fireplaces are used only about 15% of the day,
on average.
·
Poor Heat Exchange. Conventional fireplaces have minimal means to collect
heat from the flame and flue gases and transfer it to the house. Often the only heat
exchange is to the firebricks of the combustion chamber; prefabricated fireplaces
often have a second wall around the firebox through which air may pass.
·
Location on the House Outside Wall. As previously mentioned, the little heat
that most fireplaces can extract from the flame often goes into the bricks and/or
fireplace casing. With the fireplace on an outside wall, the most common
installation in North America, as much as 50% or more of this heat is conducted
directly outside and never reaches the house proper.
·
Poor Methods of Heat Transfer to the House Interior. Most fireplaces with
convective passages around their casing do not do a very effective job of actually
getting the heat to the indoors by natural convection. Therefore, many
manufacturers have installed circulating fans. However, many of these fans are
quite inefficient in their use of electrical energy, even for those few that do
happen to move reasonable quantities of air. In addition, the fans are usually noisy
and are not run for any length of time when people are around the fireplace
·
To reduce excess tramp air that a fireplace uses, many fireplaces have glass doors.
(Tramp air is air that doesn't take part in the combustion process, but is sucked out
of the house and up the chimney by the high burning rate of the fireplace.) These
units are not all that tight-fitting and still allow the fireplace to operate at high
excess-air levels. They may even increase the burning rate because air may be
more forcibly supplied to the fire, increasing overall instantaneous air demands.
On the other hand, most fireplace doors use tempered glass to withstand the heat
from the fire. Tempered glass does not transmit infrared radiation so that heat
from the flame is reduced dramatically with the doors closed. The fireplace doors
can serve to reduce the amount of heated house air aspirated up the chimney
overnight, at the tail end of the burning cycle.
·
Incomplete Combustion. The poor combustion in most fireplaces has two
consequences for efficiency. The high excess air is a major impediment to
efficient operation, of course, but there is a high level of incomplete combustion
products, as volatiles in the wood escape the flame and pass directly up the
chimney, resulting in an additional efficiency loss as well as serious pollution
problems, both indoors and outdoors.
·
Leakage when the Fireplace is not Used. Masonry fireplace chimneys have a
large cross-sectional area, using 8"212", 12"212" and even 12"216" tiles. This
represents a large leakage area either where heated house air can escape--even
when the fireplace is no longer warm, or where downdrafts of cold outside air can
enter the house. Dampers nominally serve to close off the chimney, but in most
cases they are quite ineffective, if they are even used. Devices such as roof-top
dampers can provide a much more positive seal on the off-cycle.
To ensure that fireplaces do not cause problems and major heat losses, the most obvious
solution is to seal them up and not use them. This is usually not acceptable.
People have been trying for years to improve the performance of conventional fireplaces-adding this and changing that--to little or no avail, often at significant cost. Devices such
as glass doors, "heatilator" type heat exchangers, and even using outside air supplies
improve efficiency only marginally, to the 10-20% level at best.
Air Requirements
Table 2 presents a summary of the air requirements of various residential combustion
equipment, for a typical Canadian house. The house is a bungalow with a full basement,
having a total internal volume of 498 m3 (17,500 ft3). The measure of air tightness of a
house is most often given in terms of ACH, the air change being the total volume of air
present in the house. To get some appreciation of what the number means, 0.3 to 0.5
ACH are considered necessary by many groups to ensure there is no long-term build-up
of contaminants for indoor air pollution. Some of the new, tight homes require forced
ventilation systems (often using heat recovery ventilators) to achieve this level.
There are large differences in the air requirements of residential wood-burning
appliances, ranging from a fireplace with the highest air requirement of any combustion
appliance in a house to the negligible levels of airtight woodstoves.
Fireplaces and Indoor Air Quality
After the fireplace is lit, and before the chimney gets hot and begins to draw properly,
there is often significant smoke spillage into the house, with the tell-tale result of a
darkened mantle.
Furthermore, during this high-burn period, the fireplace causes depressurization, and as a
result "searches" for air within the house. Often the most convenient opening is the
chimney of the central furnace or water heater. This can reverse the flow down the
chimney of a conventional, naturally aspirating gas appliance, disrupting combustion and
bringing the combustion products into the house. High levels of particulate emissions,
along with volatile and semi-volatile organics, are produced by the fireplace during this
period. These emissions can spill into the house or be released out the chimney to pollute
the outdoors.
At the tail end of the burn cycle, a fireplace can be a major source of another indoor
pollutant--toxic carbon monoxide (CO). The wood progresses through its burning to a
charcoal state, similar in composition to hibachi briquettes. Who would put a charcoal
barbecue in their living room? Nobody. It's too dangerous! However, overnight with a
fireplace, the draft is low and other exhausting appliances may take their air down the
fireplace chimney. Alternatively, the house itself, with its internal stack effect may
become a better chimney than the real one during this period. In either case, fireplace
combustion products can enter the house, and there is a potential for CO poisoning.
People have died this way.
Air Pollution
Aside from being a source or cause of indoor air quality problems, fireplaces can also be
a source of significant ambient air pollution. Indeed, CCRL experiments indicate that
fireplace particulate emissions can be on the order of 50 grams per hour (g/h), twice the
level of conventional "dirty" wood stoves. Visually, fireplace pollutants are not as
obvious as those from wood stoves as they leave the chimney, because they are diluted
with the high fireplace excess air levels.
Conventional "Solutions"
A Band-Aid solution is to attempt to isolate the fireplace from the house. Maybe the
best way to do this would be to put it out in the backyard and watch it through your living
room window. Another is not to use the fireplace at all, closing it off and sealing the
connection to the chimney. Inflatable plugs can do just that, on an effectively permanent
basis.
A more logical alternative, though, is to retrofit the fireplace with "tight" fitting glass
doors along with a large combustion air supply directly from the outside to the firebox.
Glass doors can cut down somewhat on the maximum air requirements of the fireplace
and they also reduce the risk of combustion gas spillage into the house at the tail end of
the burn, as well as house heated air loss during this latter period.
These actions seem simple, but are not in practice. It is difficult to find truly tight-fitting
glass doors. Moreover, tempered glass, the common material for conventional fireplace
doors, is not a good transmitter of infrared radiation, so that direct heat from the flame is
prevented from reaching the room. The outside-air supply can also create problems. The
size of the hole required to supply a conventional fireplace is very large, often 8 inches in
diameter or more. If the outside terminal becomes exposed to significant negative
pressure due to eddying wind effects, it is possible that hot combustion products may find
the air supply duct is a more convenient exhaust than the existing chimney, with
consequent risk of fire. Even if they did do their job, glass doors and outside air reduce
problems with the fireplace, but still do nothing for its miserable efficiency.
Another partial solution is to burn an "artificial" (manufactured) firelog instead of
cordwood. Manufactured firelogs, particularly those with a paraffin base, can minimize
problems by lowering the high air demand, reducing pollutant emissions by up to 80%,
and lessening the chances of combustion gas spillage into the house. Only one log is
burned at a time, so burning rates and hence overall air requirements, are much lower
than for split wood. In addition, a flame is developed over the whole surface of the
artificial log. The volatiles, which, for normal wood, come off of the log remote from the
location of the flame, are ignited and burned as they leave the wood surface, resulting in
the low pollutants levels. However, artificial logs provide almost no heat and can be
costly.
A Technical Revolution
There has been a revolution in wood combustion technology in the past few years,
brought about by efforts to reduce the pollutant emissions of wood stoves. This is
affecting fireplace designs, with remarkable performance improvements. First, let's look
at wood stoves.
Airtight Wood Stoves
A well-designed airtight wood stove can fulfill most of a home's heating needs. Most
wood stoves transfer heat primarily as "black body radiators" by long-wave radiation to
solid bodies which they can "see." They are most effective in warming up all the solid
objects such as furniture, walls, floors and people that are in their line of sight. At the
same time, natural convection is set up in the area due to the difference in temperature
between the stove surface and the room air, so that heat is moved from the stove to the
room and to other areas of the house by virtue of air motion. A few stoves also come with
a circulating fan that increases the flow of air over the stove and out into the room,
increasing convective heat transfer.
To best take advantage of the efficient heat-transfer mechanisms of a new woodstove,
one should make every effort to locate it in a major living area, where occupants spend a
large proportion of their time in the heating season, and which has at least reasonably
open access to a significant portion of the house. The temperature of the rest of the house
can be allowed to fall somewhat, resulting in a reduced overall heat demand. Tests have
shown that the net efficiency of a well-located wood stove can be higher than that of a
conventional gas or oil furnace. The seasonal efficiency of such an appliance in an
intelligent installation can actually be significantly higher than its tested efficiency,
because of this intrinsic zoning effect. There is no dilution device on an airtight wood
stove. Air requirements for such an appliance are very low. For a stove fired at 2 kg/h,
operating at an average 100% excess air, the demand for air is only about 17 m3/h, or
0.03 ACH.
Air Pollution and Conventional Woodstoves
Conventional woodstoves have been high emitters of incomplete combustion products, as
have conventional fireplaces. Wood burns in a complex manner, with the incomplete
combustion products coming off the wood remote from the location of the flame. In
conventional airtight stoves, as represented in Figure 2, including those built even 5 years
ago, a large amount of volatile incomplete combustion products (carbon monoxide,
hydrocarbons, particulates and creosote) escaped the burning process. As a yardstick,
emissions of particulates from conventional airtight stoves average around 25 g/h.
Typical Canadian home heat demands over most of the heating season are equivalent to
such stoves being fired at air flow rates of 1-2 kg/h. Most woodstoves have been
oversized for their installation--they supply heat continuously, not in an on-off fashion
like furnaces. In order not to overheat the house, air controls on stoves are usually cut
back, with dramatic increases in pollutant emissions of incomplete combustion products.
Advanced Combustion Woodstoves
Concern over the pollutants from conventional wood stoves resulted in emissions
standards (based on particulates) being set in the United States (EPA 1990) and in
Canada (CSA B415). This has led to dramatic performance improvements and emission
reductions.
New, advanced-combustion woodstoves are meeting the emissions standards. In order
to ensure clean, efficient combustion in the firing range required, major changes to the
combustion design of wood stoves were needed. New designs give better combustion and
have lower heat outputs, yielding a more useful range of operation. New designs employ
advanced combustion techniques or catalysts to reduce the amount of incomplete
combustion products and increase efficiency.
In the United States, most manufacturers initially concentrated on reducing emissions by
using catalytic converters, similar to those found in automobiles. Such equipment
performed well in the laboratory (around 2 g/h) but real-life performance was generally
poor, with emissions often in the 9-16 g/h range, due to internal leakage, warpage of the
bypass, or failed catalysts. Recent catalytic designs have been more successful, but there
is still concern about catalyst longevity. Another potential problem is that the catalyst
itself provides resistance to flue gas flow, resulting in flue gas spillage or poor
combustion performance under marginal draft conditions.
Canadian and some U.S. manufacturers have concentrated on improving the combustion
performance of the appliance itself. From the outside, the new designs appear to be
similar to those of the past, but internally they are dramatically different. They have
complex advanced combustion systems, with turbulent and preheated primary and
secondary air, firebricked combustion zones, and insulated baffles. The result is two
simultaneous combustion zones. The first is the conventional flame of wood burning,
while the second, immediately above, is an intense bluish turbulent flame which burns off
the volatiles, resulting in a complex flame and reducing the pollution considerably.
The Canadian advanced-combustion wood stoves now in the marketplace show an 80%
reduction in emissions of incomplete combustion products with a 10-20% gain in
efficiency, relative to stoves of a few years ago (see Figure 3). Such appliances can be an
effective complement to conventional heating systems in many regions of the country;
they offer the potential to displace 60%-70% of the fossil fuel used for central heating in
these regions, with a similar reduction in overall CO2 emissions. They are also ideally
suited for use in electrically heated homes, easily displacing 70% of the electricity used
for space heating.
The Preferred Option
Suddenly we now have a real solution to the conventional fireplace with its many
attendant problems and inefficiencies. Advanced-wood-combustion designs which use
preheated primary and secondary combustion air along with well-insulated combustion
zones, are beginning to be utilized to produce what can be called an advanced
combustion fireplace. Such a unit can be built-in like a zero-clearance fireplace, or
retrofitted into an existing fireplace cavity.
The new fireplace has truly air-tight, gasketed doors, a special glass window made from a
pyro-ceramic to transmit the infrared radiation from the flame to the room and a hot air
"sweeping" of the window to allow clear viewing. With the two combustion zones in
plain sight, the result is a unique, riveting, chaotic flame which is far more attractive and
hypnotically interesting than any flame burning in a traditional fireplace.
The advanced fireplace has an insulated outer casing to prevent heat loss out the side wall
of the house, good heat exchange to take heat from the flue gases, and an effective
"squirrel cage" circulating fan to supply this heat to the house (see Figure 4).
Because of the intense combustion patterns developed, the need for excess air level is
low, so efficiency is high. The requirement for house air is also minimized to about 0.04
ACH. There is very little interaction with the house air, so the chances of releasing
combustion pollutants to the indoors or in causing other combustion appliances to spill
are minimal. Even at this low air rate, provision can be made to supply air from the
outside directly to the appliance. However, because all air passes through a tortuous path
within the unit to preheat the air before it is released for combustion in the firebox, there
is no possibility of the combustion gases reversing and taking this route as an exhaust,
unlike the supply for conventional fireplaces.
Most importantly, the emissions of incomplete combustion products of the advanced
combustion fireplaces are reduced ten-fold from a conventional fireplace. Potential for
chimney fires is almost non-existent, due to the low levels of incomplete combustion
products and creosote generated.
Mass-flow through the system decreases as excess air and firing rates decrease, so
efficiency can reach 78% (see Table 1). With the outside casing insulated to prevent heat
loss to the outside, and efficient squirrel-cage fans blowing air around the convective
passage to be heated and supplied to the house, the efficiency of use can approach 70%.
Because fireplaces are usually located in a major living area, with an "open" view to
other regions of the house, these advanced design fireplaces can become extremely
effective space-heating systems, with seasonal efficiencies which can surpass their
laboratory-tested efficiencies, if utilized properly. These units are also ideally suited for
retrofit into fireplaces in baseboard electrically-heated homes, easily displacing the
majority of the electricity required for space heating.
Because of the much lower volume of flue gas products, an existing masonry chimney
should be relined with a stainless steel liner, to ensure good draft and no condensation of
combustion products. A totally new installation should use one of the high temperature
"super chimneys", designed specifically for wood burning appliances. To ensure this
performance, one should get a new wood burning fireplace which meets the emissions
criteria of either EPA 1990 or CSA B415. Only these types of advanced combustion
fireplaces may be installed in Canada' R-2000 housing.
Pellet Fireplaces and Masonry Heaters
Pelletized fuels, which are about the size of cigarette filters, and are made from wood and
other biomass wastes, can also be used in efficient, clean-burning fireplaces and other
space-heating systems similar in concept to the advanced wood stoves and fireplace.
They usually have higher capital costs than advanced-combustion fireplaces, but some
can be side-vented which avoids the cost of a chimney. The cost of pelletized fuel is
usually significantly higher per unit of energy as compared to cordwood. The ease of
handling and automated feed may be a compensating factor.
Masonry heaters are another type of fireplace that have long been common in Northern
Europe, but are rarely seen in North America. Wood is burned (ideally cleanly) at a high
rate for about a two-hour period in a masonry firebox, while the flue gases pass through
massive masonry in a complex path to remove and store much of the heat. The masonry
subsequently releases the heat to the house slowly over a long period, as much as 22
hours. The small but vigorous North American industry has made significant strides in
this area in recent years. Recent work indicates that underfire air leads to poor
combustion, inefficiencies and fairly high emissions; also, significant heat loss can occur
unless the heater is only installed on inside walls. These and a number of other guidelines
are being developed in Canada, based on laboratory and field trials, to let alternative
fireplace design be properly utilized as a clean-burning, energy-efficient heat source.
Gas-Burning Fireplaces
In the past few years, natural gas- and propane-fired fireplaces have seen dramatic
increases in sales, due to their convenience and cleaner burning characteristics. One
dilemma is that gas usually burns so cleanly that it has a transparent blue flame, with
little visual attraction to the homeowner. To counteract this, significant effort has been
expended to produce yellow gas flames that more closely resemble a wood-burning
fireplace. This is usually achieved at the expense of completeness of combustion, as
yellow in a flame indicates the presence of soot particles.
Gas Logs
The cheapest way to convert an existing fireplace to gas is to merely install what are
known as gas logs. Basically, these are solid ceramic logs placed among gas burners to
give the "burning" feeling. But gas logs have some serious problems. If the fireplace
chimney is not relined, the chance of flue-gas condensation and chimney degradation is
high due to the high-moisture fuel, low burning rate, and low temperatures. If the
fireplace is on an outside wall, there is a good chance that chimney draft will be
inadequate, the house will be a better chimney than the chimney itself, and combustion
products will be brought directly into the house, causing indoor air quality problems.
Finally, these logs will not supply any real energy to the house, and could be considered a
waste of a premium fuel. Gas logs are not appropriate for today's new or renovated
housing. (A further extension of the gas log concept is the unvented fireplace, which
exhausts its combustion products directly into the house.)
Gas Fireplaces
Gas fireplaces can offer the potential for good, efficient performance, but this is not
realized with many pieces of equipment, in spite of what might be written on the sales
literature. Until recently, there was no reasonable test standard by which the efficiency of
gas fireplaces could be determined. The Canadian Gas Association has been developing a
seasonal efficiency standard for gas fireplaces, which is in its final draft form. The goal is
to accurately represent the performance of gas fireplaces as they would normally be
installed in Canadian housing.
When appliances are tested to this standard, dramatic differences have been seen for
various technologies, ranging from less than 10% to over 70% efficiency, although most
had been claiming 80% efficiency for their product.
Canadian provinces have taken the position that since a gas fireplace can be a significant
energy user in the home, its efficiency will be regulated to a minimum level, a level
which will be raised over time.
Until the standard is finalized and the regulation adopted, real seasonal performance
numbers will not generally be available. However, it appears that by far the best
performers are direct-vent fireplaces, with radiation-transparent pyro-ceramic glass, good
heat transfer to the house, an insulated outer casing and an effective venting system to
ensure safe removal of the combustion products.
Key Points
·
Conventional wood-burning fireplaces are extremely inefficient. They can lead to
indoor air quality problems, and can result in life-threatening situations. Hence
they are incompatible with modern housing, or with housing which has undergone
energy retrofit/renovation.
·
·
·
·
Advanced-combustion wood-burning fireplaces have low pollutant emissions and
can have seasonal efficiencies greater than conventional gas or oil furnaces.
Only advanced-combustion wood-burning fireplaces meeting the EPA 1990 or
CSA B415 performance standards should be installed in new or renovated
housing.
Gas firelogs are inefficient, can result in chimney degradation, and can cause
severe indoor air quality problems. They should not be installed in today's
housing.
There is a dramatic range in seasonal efficiencies for gas-fired fireplaces, based
on the new CGA standard. It appears that direct- vent equipment with pyroceramic glass doors and an insulated casing is the only type that should be
considered for efficient energy use and good performance.
In summary, advanced-combustion wood-burning fireplaces or direct vent gas-fired
fireplaces offer efficient, safe alternatives to the outmoded and incompatible conventional
fireplace, while allowing viewing of what can be an even more attractive and interesting
flame.
Table 1. Effect of Excess Air on Fireplace System Efficiency
Excess air %
efficiency %
Sensible heat loss %
Maximum
_______________________________________________________________________
______
100
10
78
500
29
59
1,000
48
40
1,500
73
15
_______________________________________________________________________
______
Assumptions --seasoned wood at 17% moisture
--flue gas temperature of 300deg.F
--no loss due to incomplete combustion products
Figure 1:
Figure 1. Conventional fireplace schematic.
Table 2. Air Demands for Residential Combustion Appliances
Air Requirements
Cubic meters
Air changes
Appliance
per hour
per
hour
___________________________________________________________________
Conventional oil furnace
260
0.52
with barometric
Mid-efficiency oil furnace
37
0.07
Conventional gas furnace
194
0.39
with draft hood
Condensing gas furnace
29
0.06
Conventional wood fireplace
680
1.4
EPA 1990-type wood stove
17
0.03
Advanced combustion
fireplace
Figure 2:
Figure 2. Conventional woodstove schematic.
Figure 3:
23
0.04
Figure 3. Pollutant emissions for different wood-combustion technologies.
Figure 4:
Figure 4. Schematic of an advanced-combustion high-efficiency fireplace.