High Performance or Hype Performance?

High Performance or Hype Performance?
Some Real World Data
Marc Rosenbaum, P.E. South Mountain Company Martha s Vineyard, MA
Efficiency Vermont is a Registered Provider with The American
Institute of Architects Continuing Education Systems (AIA/CES). Credit
(s) earned on completion of this program will be reported to AIA/CES
for AIA members. Certificates of Completion for both AIA members
and non-AIA members are available upon request.
This program is registered with AIA/CES for continuing professional
education. As such, it does not include content that may be deemed
or construed to be an approval or endorsement by the AIA of any
material of construction or any method or manner of handling, using,
distributing, or dealing in any material or product. "
"
Questions related to specific materials, methods, and services will be
addressed at the conclusion of this presentation.
Learning Objectives!
At the end of this program, participants will be able to:"
- Participants will learn how well models conform with actual
building performance
- Participants will learn the value of sub-metering in diagnosing
excessive energy usage
- Participants will learn about how minisplit heat pumps and one
ground source heat pump perform
- Participants will learn how occupant behavior affects energy
consumption
- Participants will have some fun
Course Evaluations!
In order to maintain high-quality learning experiences, please access
the evaluation for this course by logging into CES Discovery and
clicking on the Course Evaluation link on the left side of the page.
Copyright materials
is presentation is protected by US and International
Copyright laws. Reproduction, distribution, display and use
of the presentation without written permission of the speaker
is prohibited.
© Marc Rosenbaum 2011
Bindley Residence
A Net Zero Deep Energy Retrofit on Squam Lake
Before…
Aer…
Garland Mills Timber Frames
e owner was inspired by a session on Zero Net Energy Homes at
Building Energy and wanted her renovation to be ZNE. However,
Squam Lake is on the north side…
South North elevation
and a steep hillside with trees is on the south, with Route 3 beyond. So
the envelope is extraordinary, to compensate.
is is a second home with intermittent occupancy. When occupied it
can be occupied by large groups. e first year the house was kept at
comfort temperature to get data.
Sub-metering has enabled study of energy consumption by end use.
Location
Area
Occupancy
Foundation
Walls
Roof/ceiling
Windows
Blower door results
Mechanical system
Metering
!
Holderness, NH – Squam Lake
~3,500 ft2 includes conditioned basement
Intermittent; vacation home
R42 walls, R20 slab
R52
R73
R5+
330 CFM50
W-W GSHP, closed loop vertical; SDHW
Utility; PV; GSHP; DHW
Strategies include:
•  Existing sheathing air barrier sealed with peel-and-stick tape.
•  Eaves cut off for AB continuity
•  Urethane foam stress skin panels on roof and walls - forms new
overhang for the roof
•  Four inches of rigid foam over the existing slab, then Warmboard
•  Basement (mostly finished) studded out, seven inches of closed cell
spray foam
•  Walls and roof framing have additional closed cell spray foam
•  ermotech windows and doors, triple glazed with two low-e layers
•  Blower door results – 4,000 CFM50 reduced to 330 CFM50
•  Renewaire EV130 ERV
•  WaterFurnace water-water ground source heat pump (GSHP),
vertical closed loop ground connection, radiant floor heat
•  80 sf solar DHW system, designed so collectors heat the 80 gallon
electric tank first then the 120 gallon preheat tank
•  7.5 kW solar electric system
•  Meters on GSHP, DHW back-up, and PV output
Collectors heat primary tank first, then solar tank
Meters are on the PV inverter output, the heat pump system input, and
the DHW back-up input, as well as the utility meter. ere is also a water
meter on the incoming water to the DHW system.
Meters are read by the owner at varying intervals.
Energy Model
is is an in-house spreadsheet that performs a monthly energy balance
Bindley House Data
Energy in kWh
Heating
Cooling
DHW
Ventilation
Lights/plug/other
Energy totals
DHW water, gallons
Model
2,766
--1,127
Included in other
3,600
7,493
Actual
2,360
--626
Included in other
2,497
5,483
!
Observations:
•  Data is from 12/6/08 through 12/9/09
•  Intermittent occupancy
•  Water meter mounted near ceiling facing upwards L
•  GSHP has been working very reliably and efficiently. Modest
temperature li between closed loops at about 40F and heat storage
tank at 95F, coupled with attentive design to minimize pumping
power, have yielded a system that appears to be operating above a COP
of 3.
•  Back-up heating of the DHW tank was using more energy than
expected – this was tracked to incorrect wiring of the electric elements
in the primary tank and an excessive setpoint. Once corrected, this
energy dropped to close to zero. Several months later, it jumped up
again – this was tracked to a freeze rupture in one of the collectors.
e Prototype Classroom and 1989 Wing A Deep Energy Retrofit at the Plainfield,
NH School
Marc Rosenbaum, P.E. South Mountain Company Martha s Vineyard, MA
Location
Area
Occupancy
Foundation
Walls
Roof/ceiling
Windows
Blower door results
Mechanical system
Metering
Plainfield, NH
~8,000 ft2
K-8 Public School
R15 slab edge
R45
R40
R5+
None
Cold climate minisplit heat pump; ERVs
Heat pump; ERV; lights
!
• 
• 
• 
• 
Prototype Classroom occupied Fall 2009
1989 Wing occupied Fall 2010
Windows are quad-glazed Serious Windows
Minisplits are Mitsubishi Hyperheat, rated to -13F
e Prototype Classroom Fix
•  e Prototype Classroom integrates a Deep Energy Retrofit with distributed HVAC.
•  It includes:
-  Skirt the slab-on-grade with 3 inches foam insulation
-  New quad-glazed Serious windows
-  New or repaired sheathing used as the air barrier
-  6-1/2 inches of added exterior rigid foam and new wood cladding
-  Room-by-room HVAC - a residential energy recovery ventilator and a
minisplit heat pump
Floor Plan
1989 Addition
Gym
1972 building
Prototype Classroom
2000 Addition
SPF at eave
Windows in
TimberStrand
extension bucks
3 Polyiso beneath
3-1/2 Nudura EPS
panels with integral
1x nailers
3 PerformGuard
Perforated fabric duct
Indoor heat pump unit
Renewaire EV200 energy recovery ventilator
175-180 CFM as installed - 10 CFM/person
151 Watts
85% effectiveness (measured at -3F outdoor
air temperature and 70F indoor air
temperature)
Demand controlled via CO2
No tempering coil
Measuring…
Heat pump kWh
ERV kWh, elapsed time, run time
Indoor and outdoor temperature
Relative Humidity
CO2
Also on-off for lights and ERV
Plainfield School District voted 188-57 on March 6th, 2010
for a $275K bond to extend this to the rest of the 1989
addition – this work was performed Summer 2010
12 inch SIPs on flat roof plus tapered insulation
© Marc Rosenbaum, P.E. Energysmiths 2010
Structural upgrade
© Marc Rosenbaum, P.E. Energysmiths 2010
Prototype Classroom Data
Energy in kWh
Heating
Cooling
DHW
Ventilation
Lights/plug/other
Energy totals
DHW water, gallons
Model
Actual
757
Included in heating
--184
901
1,842
---
• ! I guessed heating usage would be under 10 kBTU/2/year
•  is is based on data collected from January 8th through June 18th 2010
•  Heating and cooling energy use for the 8,000 2 wing from start of school in Fall 2010
through January 28th, 2011 has been 4,393 kWh, during a period of 4,334 HDD65.
Extrapolating to 7,800 HDD65 yields a predicted heating/cooling energy of about 7,900
kWh, or about 1 kWh/2/year.
•  It’s likely that total energy use in this wing will be less than 2.5 kWh/2/year
•  A guesstimate of heat pump COP is 2 – 2-1/2.
Bement School Residence Hall
Margo Jones Architect
Location
Area
Occupancy
Foundation
Walls
Roof/ceiling
Windows
Blower door results
Mechanical system
Metering
!
Deerfield, MA
11,000 ft2
20 student dormitory and four faculty apartments
R19 slab
R37
R60
R4
1,490 CFM50
Minisplit VRF heat pumps; ERVs; SDHW; PV
Utility; PV; HP; DHW; DHW water; apartments
•  Four Mitsubishi 3 ton (most efficient) VRF air to air heat pumps with
11 zones - 9 ducted units, 1 wall mount, and 1 floor mount
•  ree energy recovery ventilators – one for each two faculty
apartments and a 450 CFM unit for the dorm spaces
•  240 2 drainback solar thermal hot water system
•  8.6 kW solar electric system
Envelope
Mechanicals
Meters
•  Forty 215W Sanyo solar electric panels and a Solectria inverter
•  Six Heliodyne Gobi solar thermal panels in a drainback
configuration with two Vaughn 120 gallon storage tanks
Energy Model
Bement School Residence Hall Data
Energy in kWh
Heating
Cooling
DHW
Ventilation fans
Lights/plug/other
Energy totals
DHW water, gallons
!
Model
11,267
None (duh)
7,002
6,700 (estimate)
17,300
42,269
280 gpd
Actual
12,442
10,231
13,281
6,700 (estimate)
21,655
64,309
193 gpd
•  is is extrapolated to a full year from 49 weeks of data.
•  I didn’t envision more than incidental cooling but a drawback to minisplit heat pumps
is the ability to cool. e total energy into the heat pumps is measured but the split
between heating and cooling is eyeballed from the data. Weekly heat pump energy for
cooling exceeded weekly energy for heating! Using “dehumidification mode” increased
energy use.
•  e solar hot water system has never operated properly, increasing energy use by
thousands of kWh annually
•  A guesstimate from early data is that the COP is in the 2-1/2 – 2-3/4 range.
Eliakim’s Way Housing
South Mountain Company
Location
Area
Occupancy
Foundation
Walls
Roof/ceiling
Windows
Blower door results
Mechanical system
Metering
West Tisbury, MA
1,200 – 1,350 ft2 each house (2/3 bedroom)
Housing
R20 walls, R20 slab
R29
R49
R5+
117 – 184 CFM50; 236 CFM50 Habitat
Minisplit heat pump; HRV; Radiant panel; PV
Utility; PV; HP; DHW; Radiant panels; DHW water
!
• 
• 
• 
• 
• 
• 
• 
Eight affordable homes designed to be ZNE possible
5.04 kW Sunpower solar electric panels
Single zone Daikin minisplit heat pump, wall unit in living room
Enerjoy electric radiant panels in each bedroom
Fantech 704 single speed HRV runs continuously, ~45 CFM
Marathon electric water heater
PVs are located on the roof to allow additional PV or solar DHW
Envelope
Mechanicals
•  Meters are read monthly
•  HRV wattage at ~35W is too low to reliably read with these meters
•  Noticed a malfunctioning PV system (beware of 2-1/2 year olds…)
•  Currently have Hobo dataloggers measuring temperature and RH in
all four of the three bedroom houses
•  Interesting to see variation in usage between houses
•  Having water meters on the DHW inlet and also kWh meter on the
water heater allows calculation of energy used per gallon of DHW
•  e variation in how occupants use the single zone point source heat
pump and the distributed electric radiant panels is interesting
Energy Model
is model predicts 5.9 kW needed for ZNE performance
Energy in kWh
Heating
Cooling
DHW
Ventilation
Lights/plug/other
Energy totals
DHW water, gallons
!
Model
1,451
--2,673
Included in other
2,700
6,824
36 gpd
Actual
•  Aer seven months, the total usage ranges from 3,028 kWh to 5,938
kWh
•  I predict two households will achieve ZNE and use less energy than
the model, the rest will use more
DHW usage per person per day varies from 6 to 18 gallons
Energy usage to heat water is about 0.20 kWh/gallon, with
about a 75F rise – about a 0.90 EF
Thank you!
Marc Rosenbaum, P.E.
South Mountain Company
Martha’s Vineyard, MA