Danny Parker Sf Lecture Presentation
- 1. Zero Net Energy at Home walking the Talk Danny Parker May 2012 My House: Cocoa Beach, FL • 1500 ft2 with pool built in 1958 • CBS construction: totally uninsulated • Standard home of this type uses about 20,000 kWh/yr • Millions like these in FL • Started retrofits after moving in: 1989 – R19 ceiling insulation – Removed carpet for tile floor – Dropped pool pump to 4 hrs/day – Sealed ducts following summer 2
- 2. Pools are big! • Second largest end-use in homes that have them (4000 kWh/yr) • Ready design solutions – Larger piping/low friction filters – Two-speed pumps • Potential to cut by 70% • Solar pumping cuts peak energy end-use ETAEngineering.com 3 CFLs, ventilation, WH Fan, Washer, Dishwasher…it goes on 4
- 3. Solar control low-e windows, wall insulation, mini-split heat pump … 5 Real-time Feedback & Monitoring 6
- 4. 4.1 kW of PV : January 2009 • Produced 6,542 kWh over year • Produced 99% of power used • Added 800 Watts in Nov. • Used 155 total therms • New plan: insulate walls, replace windows • Install ductless SEER 26 mini- split HP and ditch AC & ducts • Close to zero net 7 Not everything was helpful- (energy wise) 8
- 5. Done 9 How much did it cost? • Natural Replacement so incremental only – White metal roof: $4000 – Sealed ducts/insulation: $400 – PV pumped pool: $3600 – Ventilation fans: $500 – Whole House fan: $300 – CFLs everywhere: $400 – Solar hot water: $2000 – TED/Isole: $500 • PV: $30K less $9K tax credit & (possibly) $16K state rebate Wanted Anyway: Tile floors, gas cooking, Flat screen TV, new dishwasher, new washer, • Total: ~$32 K over 20 yrs new AC, new refrigerator • Saves ~$2600/yr vs. avg use 10
- 6. 11 Why stop there? • New Chevy Volt • Gasoline since late September: 0.7 gallons • Electricity: 6.0 kWh/day • 25-30 miles a day; no gas • Saves $2.50 a day • Gas: $0.14/mi • Electric: $0.04/mi
- 7. Look Mom, no Utility Bill… • No bill! FPL paid me • Even with the car • Avg. Floridian spends $2,000 a yr. on utilities and $1,500 on fuel for the primary car. $300/month • I spend that money on coffee shops, movies and local restaurants…. Jobs Now? New Jobs? 14
- 8. Contentment…your own personal zero energy Life of Riley 15 Mini-split Heat Pumps for Retrofit Cooling Applications Danny Parker Southface Institute May 2012 1
- 9. Overview • How they work • Technology • Potpourri of data on cooling • Room temperature variation • What we know; what we don’t (e.g., zoning) How do they work? • Outdoor unit connected to indoor unit by direct refrigeration line (no duct losses) • Mini-split: Zoned control of space • Multi-splits: Up to four units can be placed inside • Multi-splits are generally less efficient, but can reduce the number of outdoor units 3
- 10. Mini-Split Technology • Not new! Millions in use in Asia/Europe • Small size; ideally suited to low-e homes • Inverter controlled DC compressor speeds • Higher efficiency • Variable speed blower • Electronic expansion vs. TXV; hi-tech defrost 4,000 – 24,000 Btu/hr Very High Efficiency Inverter Controlled Heat Pumps
- 11. LW4 NEEA Ductless Heat Pump Study in the PNW: Ecotope Usage Profile 1 Total 7-day Usage~ 7 kWh! NEEA’s NW Ductless Heat Pump Project www.nwductless.com Slide 6 LW4 I edited to give credit to NEEA and include website lwigington, 10/23/2011
- 12. LW25 Total 7-day usage ~ 26 kWh! Slide 7 LW25 Danny - this is the same site - two different weeks lwigington, 10/23/2011
- 13. LW24 SMUD Experience kWh Estimated Jean Electricity vs. Actual Electricity Use • Good 1600 Estimated Pre Retrofit Electiricty Use Actual Kwh is 38% < estimated existing, Estimated Retrofit but 20% > than predicted savings 1400 Electiricty Use Actual Electiricty Use 1200 • But some 1000 reliability 800 problems 600 • Some 400 aesthetic 200 issues 0 May, 2011 June, 2011 July, 2011 Slide 8 LW24 Proof reader recommends eliminating word "but" in 2nd bullet - I defer to you. lwigington, 10/23/2011
- 14. Ward Lutz Experience • Fujitsu 9RLS LW5 • 575 ft2 bungalow • Built in 1950 • Western Ohio • Now super-insulated • Used 2-3 kWh per Most cooling loads day for cooling with from internal sources temps above 90º F Slide 9 LW5 FYI - You may want to indicate that is one of frst homes to meet the THC, and now, with addition of PV is net zero, He met THC prior to adding DHP or PV. Ward did not think he would need AC, but house summer interior temps were higher than pre-retrofit (even with low baseload). He added DHP this past winter for heating and summertime cooling and dehumidification. One of issues is trapping internal gains - other is that he is no longer ground coupled - he isolated the crawl space from the house - Link to case study is inserted in notes below - I need to add recent data. lwigington, 10/23/2011
- 15. LW6 O’Neill House • No compromise Passive House in Sonoma, California • 2,400 ft2: super insulated; super tight (0.38 ACH @ 50Pa) • Mitsubishi Mr. Slim mini- split HP • Low-energy cooling LW7 • But little cooling in Sonoma (est. use 225 kWh/yr) Data: Jeremy Fisher and Brennan Less, Energy Performance of Buildings Group, LBNL Slide 10 LW6 ONeill is spelled with 2 lls They refer to their project as Passive House, not PassivHaus on project websites I added ACH 50 - feel free to delete if you think it adds too much clutter - super tight means many different things to different people I added reference to LBNL under temp graph and on next 2 slides lwigington, 10/23/2011 LW7 Recommend last bullet change to( est. use 225 kWh/yr.) (i changed - LW) Proof reader recommends eliminating word "but" from last bullet - I defer to you. lwigington, 10/23/2011
- 16. O’Neill House (monitored kWh) Jeremy Fisher and Brennan Less, Energy Performance of Buildings Group, LBNL Summer Operation: Comfort Jeremy Fisher and Brennan Less, Energy Performance of Buildings Group, LBNL O’Neill Passive House: June 17 -22, 2011
- 17. My House: Cocoa Beach, FL • Built in 1958 LW11 • 1,500 ft2 with pool LW10 • CBS construction: totally uninsulated • Typical energy use for this housing type ~20,000 kWh/yr • Millions like these in Florida • Started retrofits after moving in: 1989 – R19 ceiling insulation – Removed carpet for tile floor – Dropped pool pump to 4 hrs/day 13 – Sealed ducts following summer Slide 13 LW10 CBS is very common term to FL - but may not be known to folks where CBS is not common. recommend spelling out lwigington, 10/23/2011 LW11 Is 20,000 kWh.yr total household energy or just electricity? Clarify Does standard home of this type use about 20,000 kWh.yr? I changed wording - Make sure my change is OK lwigington, 10/23/2011
- 18. Scads of Retrofits • Solar hot water with tankless gas backup • PV DC pumped pool • White metal roof • Sun pipe interior lighting • Low energy refrigerator 14 CFLs, Ventilation, WH Fan, Washer, Dishwasher…It Goes On 15
- 19. Long-term Electricity Consumption Utility & Retrofit History for Parker Family • Utility records Cocoa Beach, 1989 - 2011 since 1989 1800 Monthly Electricity Consumption 12-month moving average 1600 • Big drop with early R19 FPL Average Use: 17,207 kWh/yr or 1,434 kWh/month 1400 Seal +500 ft2 conservation 1200 Ceiling & tile floor Ducts WHFan & new Frig Remodel Add 2nd Flat Screen & DVR PV Pool Frig measures 1000 CFLs White Pump New AC ES Ceiling Fans Remove Energy Feedback ES Dish- washer 4.1 kW Roof Freezer & WHF PV Monthly kWh HiEff • Steady for a decade 800 Solar DHW & Gas ES Washer Windows Wall Ins. & Minisplit Add Add although adding 600 Freezer 0.8 kW PV ES Kitchen Fridg 50% floor area & 400 two more people! 200 * Sarah * Wade Zero Electricity Objective 0 • Zero in 2011 -200 -400 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Year: 1989 - 2011 Very High Efficiency Mini-split • SEER 26 mini split • Heat Pump – HSPF= 12.0 • 9,000 Btu/hr output • Abandon duct system
- 20. Very High Efficiency Mini-split • Operate for space heating rather than natural gas • Outdoor unit on west side of house • Very quiet operation • Only 196 kWh for space heat for all of 2010-2011 • Mini-split power was about the same as blower power on gas furnace! Variation in Room-to-Room Temperatures • Used HOBO loggers to evaluate temperature variation • Note wide temperature spread during heating season • Even without space conditioning, lots of variation • Impact of closing off rooms
- 21. Summer Operation: Power LW13 --- Condenser --- Air Handler ---Mini-split Contrast Mini-split with Central System Slide 20 LW13 I used text box to increase readability of key lwigington, 10/23/2011
- 22. Summer Operation: Comfort LW14 --Thermostat Temp --Thermostat RH --Living Room Temp --Living Rooms RH --Tile Temp Contrast Mini-split with Central System Slide 21 LW14 I inserted text box to increase readability of key lwigington, 10/23/2011
- 23. Energy Reduction from Using Mini-split • Cooling energy July 3-9 LW with Central System: ----Condenser – 20.7 kWh/day (3.5 kWh/AHU) ----Air Handler ----Mini-split – Interior temp: 79.1º F – Ambient: 82.0º F (75.8-91.5 ) • Cooling energy July 10-16 with Mini-split: – 8.9 kWh/day – Interior temp: 79.3º F – Ambient: 82.3º F (73.8 – 93.6) • 57% savings, even though www.infomonitors.com/dpr hotter in post period Slide 22 LW16 I Used text box to make key bigger - lwigington, 10/23/2011
- 24. Summer Operation: Power LW ----Condenser ----Air Handler ----Mini-split Contrast Mini-split with Central System Slide 23 LW17 I inserted text box to make color key bigger lwigington, 10/23/2011
- 25. Contrast Mini-split with Central System Mini-split with Central Fan
- 26. How to Equalize Room Temperatures? • Multiple mini-split heads • Circulation fans (Panasonic Whisper Green ceiling insert fans) • Use existing air handler to circulate air • Consider low energy AHU motor (Concept 3) • Small customized interior ducts, as Dave Robinson will show… Cost • Mini-splits: $2,500 - $4,000 installed per unit LW19 • $1,000 + for multiple heads • Multi-split with multiple heads tend to be ~20% less efficient • Cost often reflects efficiency • Cost for one mini-split per bedroom is similar to central system • May be less if duct system does not exist, however • How many are really needed?
- 27. Slide 27 LW19 I would change" 3,500" to $4,000 - $4,000 is very common - $2500 is pretty exceptionally low. lwigington, 10/23/2011 LW21 State of Knowledge • What we know… Can a single mini-split – Best efficiency mini-splits can provide efficient cooling cut cooling needs by 30%-70% option for hottest days? – Hi-SEER with quiet operation – No duct leakage, conduction • And what we don’t… – What are zoning savings? • 1985 GRI study showed zoned heat savings of 31% in 25 PA homes – What are room temperature distribtions compared w/central? – Peak load of multiple systems? Single distributed?
- 28. Slide 28 LW21 Maybe add something about disribution needs could differr if goal is reduction of latent vs sensible load lwigington, 10/23/2011 Conclusions: Mini-split Hi-efficiency Advantages: LW23 – Millions in use worldwide! – Very quiet operation – Efficiency > SEER 20 – Fractional ton sizes – No duct losses (leakage/ conduction) = 20% reduction – Zoning = 20% less energy – Good RH control – Easy to retrofit (no ducts) – Good retrofit for window units & central systems
- 29. Slide 29 LW23 I think it is important to add that they work very well on partial load - efficiency goes up Also that they could also substantilly reduce heating vost/ loads too with either expensive fuel or inefficient system lwigington, 10/23/2011 Conclusions (cont.) • Distribution is important – One mini-split per bedroom? – Really needed? One per floor? – Distributed single systems? – Enhanced by good insulation/windows LW22 • Disadvantages: – Expense similar to central – Condensate for each head – Some don’t like appearance of indoor & multiple outdoor units) – U.S. AC trade may discourage
- 30. Slide 30 LW22 Under disadvantages maybe add something about ratings not reflecting true performance. lwigington, 10/23/2011 FLORIDA SOLAR ENERGY CENTER A Research Institute of the University of Central Florida Zero Net Energy Homes for the Southeast Key Takeaway Points: New & Existing Danny Parker Southface Institute, May 2012
- 31. Success in a Nutshell Cut total electrical loads to 25 kWh/day Tall order, but that’s success Think less house, more efficiency: McMansions: Just say No. Existing: Insulate what you can; optimize at time of replacement Analyze utility bills to isolate heating/cooling costs Add 5 kW PV system with inverter Understand that the cost effectiveness of everything follows from the cost effectiveness of PV system Effective solar water heating system: tankless gas auxiliary Solar control measures to reduce cooling Well insulated building to reduce heating loads; use fully condensing gas for auxiliary Efficient appliances: refrigerators, dishwashers, washers, TVs Real time Energy feedback to guide success Floors for ZEH Tile floors are best in hot climates; free cooling, half a ton in early summer Use throw rugs for comfort Seasonal adjustments Use R-5 perimeter insulation Crawlspaces: R-19 floor insulation Existing Homes: consider tile or wood in cooling climates when re-flooring
- 32. Walls for ZEH Variety of solutions Minimum R-11 insulation Inspected Advanced framing/insulated headers Existing: Spider® system for frame Performance IR inspection in winter/summer peak R5 to R6 exterior sheathing is important Consider for existing if re-siding Choose light pastel paint color in hot climates Windows for ZEH High performance solar control windows Non-metal frames SHGC <0.31 U-factor < 0.35 Btu/hr/sqft-F. Choose above at time of window replacements; otherwise not cost effective Attempt to orient more to south; fewer to the west– particularly in hot locations Glass to floor area ratio 15% or less Minimum 2 ft overhangs on south; 3 ft is better
- 33. Ceilings for ZEH R-38 insulation; R-49 in cold climates Advanced framing Add to above levels for existing Inspected for consistency Consider IR camera for existing Use insulated recess cans Ducts buried in insulation if in attic Insulate over garage in hot climates Roof for ZEH Hot climates: Prefer light colored tiles or cool metal Radiant barrier underneath Light colored metal is a good choice Existing: Make appropriate choices at time of re-roof; otherwise not cost effective If insulated roof deck then consider at least R- 30 with light colored tile Well sealed Consider that roof pitch strongly influences performance
- 34. Duct System Strongly prefer ducts in conditioned space under insulated ceiling 10% influence on heating& cooling Contained in false ceiling Otherwise: Buried in deep ceiling insulation Under sealed attic with roof deck insulation Ductless heat pumps: great for new and existing Ducts should be well-sealed and tested Prefer round duct to flex duct= lower friction and fan power Cooling System Consider NightBreeze system or other whole house fan or economizer system in mild dry climate (e.g. San Jose) Consider sizing for adequate moisture removal in humid climates Auxiliary AC should have minimum SEER 15 Consider advanced systems: SEER 19+ and HDAC systems Consider ductless mini-splits for existing; solves two problems; very high performance
- 35. Heating System Fully condensing gas furnace (92%+) Or utilize tankless gas heater with hydronic loop Geothermal ground loop system may not provide expected performance! Beware pump power Mini-split heat pumps are very efficient, eliminate duct losses and provide zoning Refrigerator Most efficient refrigerator of the size and type you can find Existing: Measure your refrigerator energy use over a day long period. If it uses more than 3 kWh/day, replace it with the above Top freezer types are most efficient Resist 2nd frig and separate freezer If you have a 2nd refrigerator; measure it. If it uses more than 3 kWh/day, recycle it. Turn off moisture control
- 36. Water Heating Solar Water Heating Use Integrated Collector storage system if no freeze danger Better performance from open loop active system 40 sqft collector DC solar powered pump for simple operation Tankless gas backup (~77% efficiency) Elevated so hot water migrates to tankless gas Reduces auxiliary and scaling rates Electric: Heat Pump Water Heater (Air Tap for retrofit); COPs of 2-3; nearly as good as solar system Beware of hot water recirculation systems without occupancy controls Major appliances Prefer gas appliances (reduces source energy) Gas range with true venting range hood Gas dryer (supplemented by clothesline) Gas auxiliary heating (min AFUE= 0.81) If all electric, choose most efficient range, dryer and heat pump Existing: Replace appliance with most efficient models at point of natural replacement Horizontal axis (front load) clothes washer Cuts power by 30% for wash; reduces water use Reduces dryer energy by 10-20% Run in afternoons with solar hot water Energy Star Dishwasher Choose highest efficiency model using Energy Guide label Short insulated plumbing runs to water heater Run in afternoon with solar hot water
- 37. Other Appliances Choose LCD flat screen TV vs. plasma (40% reduction!) Design controllable circuitry to allow turning off all elements of home entertainment center other than DVR Use smart switch for entertainment center Provide similar circuit to home office to allow dispatch of all computer and peripherals except CPU & wireless router (otherwise use Isole or equivalent) Induction cooking if electric; venting range hood Photovoltaic System At least 4 kW for modest sized home Will produce about 16 kWh/day 5-6 kW for larger home or existing home Will produce about 20 - 25 kWh/day Evaluate annual load to avoid purchasing more PV than needed Exercise care that there is not array shading by trees, or architectural features (chimneys etc.) Try to use true south orientation to maximize output Zero Electricity home must live within these budgets Provide user display to assure proper function Wash array in early summer & late fall in dusty areas
- 38. Real Time Feedback Use real-time electricity feedback for home Preferably have similar device to show real- time PV system output Minimize home loads vs. PV system output Reminders & altering household behavior Monitor performance as new appliances added, for cleaning array of dust etc. Collect utility records to obtain long-term performance Successful Zero Net Energy Homes in the Southeast: What’s New? Danny Parker Southface Institute, May 2012
- 39. Many new ZEH… • ORNL • NREL • Building America teams • Independent builders • This one in Wheatridge, Colorado is true ZEH
- 40. New Vital Understanding of Cost Effectiveness for ZEH • Cost effectiveness is different for ZEH home • Defined by cost to produce one kWh/day • Generally 1 kW of PV will produce about 4 kWh/day • Cost: $6500/kWDC • Cost 1 kWh/day= $1600 • Efficiency measure is cost effective that can reduce 1 kWh/day for less than $1600 Site shading for Renewable Features: Big Deal… • Solar Water Heating • PV performance impact
- 41. Digitized Shading Evaluation Cool Shingles • 25% reflectance • Plus color • GAF Timberline Cool Series • $50-$100 more per square
- 42. Poor Performance from GSHPs • Geothermal heat pump performance • Two GSHP systems • Panama City: 1.5-ton Closed loop system with 200’ vertical well • Gainesville, 2-ton, open loop GSHP, 120 ft well Closed loop GSHP: Specs • Florida Heat Pump – GT018 - 1VTC • 1.5 ton unit – Closed loop with vertical injection well – ISO 13256 EER= 18.3 Btu/Wh, Capacity = 16,000 Btu/hr – 1/6 hp Grundfos circulation pump (6.4 gpm)
- 43. Performance of Closed Loop GSHP Panama City ZEH Closed-loop 1.5-ton Geothermal Heat Pump Performance: September 30th 2008 2200 80 75 2000 dT 70 1800 65 60 Geothermal HP Power 1600 GSHP Total Power: 14.6 kWh 55 Temperature (oF) 1400 Loop Circulation Pump: 2.2 kWh 50 Supply air temp: 61.7 F 1200 Interior temp: 73.3 F 45 Return air temp: 73.4 F 40 1000 35 800 30 25 600 20 400 15 10 200 5 0 0 0 2 4 6 8 10 12 14 16 18 20 22 24 Hour of Day: September 30th 2008 Panama City ZEH Closed-loop 1.5-ton Geothermal Heat Pump Performance: September 30th 2008 (Tested air flow = 660 cfm) 12 105 EER: 7.4 Btu/Wh 11 Runtime Fraction (0 - 1.0) 100 Supply Temp: 61.7 10 Interior Temp: 73.4 F Fluid 95 Return Temp: 74.3 F dT Geothermal HP EER (Btu/Wh) 9 Return fluid t: 89.2 F 90 Leaving fluid t: 94.5 F 8 Temperature (oF) 85 EER =8.5 Btu/Wh 7 @77 F return T 80 6 75 5 70 4 Air side dT 65 3 2 60 1 55 0 50 0 2 4 6 8 10 12 14 16 18 20 22 24 Hour of Day: September 30th 2008
- 44. High Efficiency Motor Retrofit • Save 50% of blower power • Converts to Variable speed motor • Better humidity control & more quiet Newer, Bigger Televisions… • Now as many TVs as occupants in average U.S. household • TVs on an average of 6 hrs/day • Owned for ten years • Growing electrical demand; large HDTVs: 100 W to 600 W • Plasma is generally worse, but lots of variation • Energy Star labels: Nov. 2008 • FTC Energy Guide: 2011
- 45. Very High Efficiency Inverter Controlled Heat Pumps New DC Ceiling Fan Motors • New DC ceiling fan motors drop power use by 70% • Several manufacturers: – Monte Carlo – Emerson • Emerson Midway Eco is most efficient model – 24 Watts on high speed
- 46. Hot Water System Laboratory • Tankless gas systems save approx. 22% measured vs. storage systems (COP = 0.73 vs. 0.57) • Tankless electric saves 4% vs. standard storage tank • Solar Water Heaters: (March 2009- Feb 2010); referenced to electric storage tank – ICS: 47% reduction in energy – Flat plate: differential control; pumped: 78% reduction – Flat plate: PV pumped: 74% reduction Importance of Pipe Insulation • Non-solar systems: no measureable change • Dramatic impact on solar systems – Flat plate differential system: • COP increase to 5.54 to 8.30 • Solar fraction to 84% to 89% – PV pumped system: COP from 3.69 to 6.06 • Solar fraction to 76% to 85% – ICS system: COP from 1.86 to 2.12 • Solar fraction to 51% to 58% • ½” rubber closed cell foam insulation: R-2; recommend 1” insulation be used on solar circulation piping at a minimum
- 47. Typical Solar system: Flat Plate Surface area: 40 sqft – Loss coefficient: 0.734 Btu/sqft-F – Transmittance absorptance: 0.78 – Storage tank volume: 80 gallons – Two tank system with natural gas – Heat exchanger correction factor: 0.88 – 120 Watt pump 2 kW PV system….
- 48. More efficient washing machines &… • Cold water detergents greatly reduce energy for washing clothes • Most of washing machine energy is for heating water • And for removing water leftover from the spin cycle for the energy-gobbling dryer • Want a high EF Need: Better clothes dryers • Clothes dryers: 4% of U.S. energy • More electricity than modern refrigerators: ~800 kWh a year • 45 therms a year for gas • Crude devices – 3.01 lb of clothes/kWh – 53% efficiency is typical • Large potential efficiency gains 0 Energy 800 kWh – Heat pump source – Heat exchanger 45 therms – Improved controls
- 49. Bosch: Heat Pump Clothes Dryer • EcoLogixx WTW86560AU Cuts energy use in half for electric clothes dryer • Uses heat pump & heat exchanger EnergyGauge USA V. 2.8 • Version 2.8 is released… • Faster, more powerful • Improved rendering of building geometry, heat pumps, cool roofing. • Simulation of photovoltaic systems • Solar water heating systems (active & batch) • Hourly output of energy-end use, thermal and humidity data • New TMY3 weather data
- 50. Evaluation of ZEH Designs • Same home in Tampa… • Add 2 kW PV array south • PV System #2 is identical, but faces west • Which better? • West better matches load shape, but building is far too inefficient for PV! • Make it more efficient! BEopt • NREL • Building Energy Optimization • Hourly simulation engine • Research Tool • Evaluates all options for new buildings • Not available to general public
- 51. TED 5000 is awesome…. • The Energy Detective (TED) • $350; installs in minutes • Instantaneous feedback • True kW, can show both house and solar output • Send signals over house wiring; also internet gateway • Current data; monthly cost • Data available on Google Power Meter and TED Footprints http://www.theenergydetective.com • Google Power Meter in limbo Real-time Feedback & Monitoring
- 52. Ideas about what makes a difference AC Refrigerator Google Power Meter Goodies Week Month
- 53. PV Display Devices…. • Sunny Beam for SMA inverters • Wireless, auto downloads data to PC • Displays total power today so far • Current output • Last 30 days • Total Annual kWh Measure your way to success…
- 54. Open Loop Water Source GSHP • Energy use only Gainesville ZEH Open-loop 2-ton Geothermal Heat Pump Performance: August 15th 2008 15.4 kWh/day 2200 80 – Unoccupied 75 2000 • Specs called for ½ 1800 dT 70 65 hp pump; 1 hp pump 1600 60 Geothermal HP Power was installed GSHP Total Power: 15.4 kWh 55 Temperature (oF) 1400 Well Pump: 9.3 kWh 50 Compressor & Fan: 6.1 kWh • 180 FOH, 1/3 hp 1200 Supply air temp: 59.2 F Interior temp: 75.2 F 45 could work 1000 Return air temp: 75.2 F 40 35 • Note that pump 800 30 25 power is 60% of 600 20 total system power 400 15 10 • Compressor/fans is 200 5 only 40%! 0 0 2 4 6 8 10 12 14 16 18 20 22 24 0 Hour of Day: August 15th 2008 Winter Infiltration Results from the FRTF Laboratory Building America Stakeholders Meeting Austin, TX March 1 2, 2012 Philip Fairey, Danny Parker A Research Institute of the University of Central Florida
- 55. Project Objectives Under side by side, in situ controlled conditions: • Measure effectiveness of various energy retrofit improvements • Produce high quality empirical data set useful for home energy simulation verification. FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida • Two identical side by side 1536 ft2, concrete block, slab on grade residences • Single pane fenestration, evenly distributed • No concrete block wall insulation • R 19 ceiling insulation (current code minimum) • SEER 13 w/strip heat HVAC systems FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 56. Lab Home Floor Plan Interior walls not present in current test configuration 32’ 0” 48’ 0” FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida Occupancy Gains • Automated (computer controlled) heat and moisture gains scheduled by time of day • Based on RESNET lighting, appliance and miscellaneous energy usage amendment • Imposed using BA benchmark hourly schedules with slight modifications • Includes lighting and appliance gains and occupant gains – Sensible gains 15.5 kWh/day – Latent gains 12.1 lb H2O/day FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 57. Scheduled Internal Gains FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida Enclosure Air Leakage Set Up • Both home enclosures air tightened to achieve 2.5 ach50 • Air distribution systems in both homes tightened to achieve 20 cfm25 (Qn=0.013) • Leaky home configured with 4 controllable ceiling leakage sites providing ~70% of leakage area needed to achieve ~9 ach50 • Remaining 30% of leakage area in leaky home achieved using metal shims at all windows. FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 58. Ceiling Infiltration Sites Ceiling side port Attic side port FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida Enclosure Leakage Test Results Leakage Parameter: Leaky Home Tight Home cfm50 1926 520 ach50 9.17 2.48 C 182.3 36.0 n 0.603 0.683 R sq 0.99805 0.99983 ELA (in2) 118.9 26.3 SLA 0.000538 0.000119 FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 59. January Temperature Data FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida Average Day During Tests FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 60. January Heating Data FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida Average Day Heating Energy FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 61. Heating Energy Characterization Outliers due to building thermal capacitance FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida But . . . It’s Still the Humidity! FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 62. January Indoor RH Histogram FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida Why Leaky is Dryer FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 63. Estimated Infiltration Rates (Moisture storage and condensation not included) FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida General Findings • Moisture control is a critical issue – More than 70% of hours exceeded 70% RH in tight home – Only 8% of hours exceeded 70% RH in leaky home – Significant condensation on single pane windows and glass doors in tight home led to local mold growth during tests • Mild weather resulted in humidity control issues in both lab homes – Outdoor dewpoint temperatures sometimes to high for effective indoor RH control in leaky home – Tight construction exacerbates mild weather humidity issues – Enthalpy controlled ventilation systems should be evaluated in light of humidity control results. FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 64. Window Condensation Condensation on all windows No condensation on of tight building windows of leaky building FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida Window Condensation Much less condensation on screened portion FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 65. Window Condensation FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida Tight Home Glass Door Conditions Water on floor from Mold on drywall at door condensation bottom of door FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 66. Tight Home Window Mold FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida Some Caveats • Lab homes have little moisture capacitance – No interior walls – No carpeting and no furnishings • Lab homes operation is atypical – No exterior door openings – No kitchen or bathroom ventilation fan operation • Could internal moisture generation schedule be the largest source of humidity control problem? FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 67. Immediate Follow up Tests • Immediately following the January test period – Lab homes were dried out by eliminating internal moisture generation and air conditioning as much as possible – Internal moisture generation was cut in half from 12.10 lb/day to 6.05 lb/day • On February 8th, the heating systems in both lab homes were reactivated • Cold snap on February 11 14 allowed additional measurements under the revised internal moisture generation schedule. FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida February Drybulb Temperatures FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 68. February Heating Energy FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida February Indoor Relative Humidities FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 69. February Indoor RH Histogram FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida February Dewpoint Temperatures Leaky home tracks outdoor dewpoint during this period FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 70. Re Test Implications • Halving internal moisture generation results in significant difference in percentage of hours exceeding 70% RH • Indoor RH during cold period is 25% greater in tight home compared with leaky home • On February 14th indoor dewpoint in leaky home is virtually identical to outdoor dewpoint • Additional outdoor ventilation air is needed to better control indoor humidity in tight homes. FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida Questions? A Research Institute of the University of Central Florida
- 71. Extra Slides A Research Institute of the University of Central Florida Just Before the Cold Snap! FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida
- 72. Null Tests – No HVAC FLORIDA SOLAR ENERGY CENTER — A Research Institute of the University of Central Florida