High Performance or Hype Performance? Marc Rosenbaum, Some Real World Data. Marc Rosenbaum, P.E. South Mountain Company West Tisbury, MA

Transcription

1 High Performance or Hype Performance? Some Real World Data Marc Rosenbaum, P.E. South Mountain Company West Tisbury, MA

2 Welcome NESEA is a Registered Provider with e American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-aia members are available on request. is program is registered with the 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.

3 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 Copyright Materials

4 Learning Objectives 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

5 Bindley Residence A Net Zero Deep Energy Retrofit on Squam Lake NH Before

6 Garland Mills Timber Frames A er

7 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 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.

8 Location Holderness, NH Squam Lake Area ~3,500 ft2 includes conditioned basement Occupancy Intermittent; vacation home Foundation R42 walls, R20 slab Walls R52 Roof/ceiling R73 Windows R5+ Blower door results 330 CFM50 Mechanical system W-W GSHP, closed loop vertical; SDHW Metering Utility; PV; GSHP; DHW!

9 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

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13 Collectors heat primary tank first, then solar tank

14 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.

15 Energy Model is is a homemade spreadsheet that performs a monthly energy balance

16 Energy Model Bindley House Data Energy in kwh Model Actual Heating 2,766 2,360 Cooling DHW 1, Ventilation Included in other Included in other Lights/plug/other 3,600 2,497 Energy totals 7,493 5,483 DHW water, gallons! Observations: Data is from 12/6/08 through 12/9/09 Intermittent occupancy Water meter mounted near ceiling facing upwards L

17 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.

18 e Prototype Classroom and 1989 Wing A Deep Energy Retrofit at the Plainfield, NH School

19 Location Plainfield, NH Area ~8,000 ft2 Occupancy K-8 Public School Foundation R15 slab edge Walls R45 Roof/ceiling R40 Windows R5+ Blower door results None Mechanical system Cold climate minisplit heat pump; ERVs Metering Heat pump; ERV; lights! Prototype Classroom occupied Fall Wing occupied Fall 2010 Windows are quad-glazed Serious Windows Minisplits are Mitsubishi Hyperheat, rated to -13F

20 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

21 1989 Addition Prototype Classroom Floor Plan Gym 1972 building

22 SPF at eave Windows in TimberStrand extension bucks 3 Polyiso beneath 3-1/2 Nudura EPS panels with integral 1x nailers 3 PerformGuard

23 Perforated fabric duct Indoor heat pump unit

24 Renewaire EV200 energy recovery ventilator CFM as installed - 10 CFM/person 151 Wattd 85% effectiveness (measured at -3F outdoor air temperature and 70F indoor air temperature) Demand controlled via CO2 No tempering coil

25 Heat pump kwh ERV kwh, elapsed time, run time Measuring... Indoor and outdoor temperature Relative Humidity CO2 Also on-off for lights and ERV

26 Plainfield School District voted on March 6 th, 2010 for a $275K bond to extend this to the rest of the 1989 addition this work was performed Summer 2010

27 12 inch SIPs on flat roof plus tapered insulation

28 Structural upgrade

29 Prototype Classroom Energy in kwh Model Actual Heating 757 Cooling Included in heating DHW --- Ventilation 184 Lights/plug/other 901 Energy totals 1,842 DHW water, gallons ---! is is based on data collected from January 8th through June 18 th 2010 Heating and cooling energy use for the 8,000 2 wing from start of school in Fall 2010 through January 28 th, 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.

30 Bement School Residence Hall Margo Jones Architect

31 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 drainback solar thermal hot water system 8.6 kw solar electric system

32 Envelope

33 Mechanicals

34 Meters

35 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

36 Energy Model

37 Energy in kwh Model Actual Heating 11,267 12,442 Cooling None (duh) 10,231 DHW 7,002 13,281 Ventilation fans 6,700 (estimate) 6,700 (estimate) Lights/plug/other 17,300 21,655 Energy totals 42,269 64,309 DHW water, gallons 280 gpd 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 not yet 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.

38 Eliakim s Way Housing South Mountain Company

39 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

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41 Envelope

42 Mechanicals

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44 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

45 Energy Model is model predicts 5.9 kw needed for ZNE performance

46 Energy in kwh Model Actual Heating 1,451 Cooling --- DHW 2,673 Ventilation Included in other Lights/plug/other 2,700 Energy totals 6,824 DHW water, gallons 36 gpd! A er nine months, the total usage ranges from 4,539 kwh to 8,758 kwh I predict two households will achieve ZNE and use less energy than the model, the rest will use more

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53 DHW usage per person per day varies from 6 to 17 gallons

54 Energy usage to heat water is about 0.20 kwh/gallon, with about a 75F rise about a 0.90 EF

55 Thank You Marc Rosenbaum, P.E. South Mountain Company West Tisbury, MA