Zero Net Energy at Home walking the Talk

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