1. TVA Near Zero Energy High Performance Homes Research Project
Energy Efficiency/Weatherization –
New Technologies
TVA Near Zero Energy High Performance Homes Research Project
March 30, 2010
Frank Rapley, General Manager TVA Efficiency Program Design
Regional Marketing, Member Services & Communications Conference
Savannah, Georgia

2. Today’s Discussion TVA Campbell Creek Research Project Project Scope
Simulated Occupancy
Test Home Overview
High Performance Home Features
House 1 – Builder House
House 2 – Retrofit House
House 3 – Near Zero-Energy House
Monitoring and Occupancy Simulation Evaluation
Key Takeaways

3. Overview
TVA built three experimental homes at Campbell Creek in East Tennessee to evaluate the effectiveness of residential construction and efficiency technologies in a controlled environment
TVA and its partners, Oak Ridge National Laboratory (ORNL) and EPRI, will be evaluating over the next few years:
residential building techniques
energy efficiency technologies
demand response concepts
consumer energy-use behaviors
TVA will use the results to develop the best, most cost-effective residential energy efficiency and demand-response tools to educate builders, developers and consumers

4. Project Scope Construction began in FY 2008
Three houses completed and turned over to TVA at the beginning of 2009 calendar year:
Builder House
Retrofit House
Near Zero-Energy House
Simulated occupancy started June 2009
Over 300 sensors and measurements in the houses

5. Simulated Occupancy Done automatically by installed control systems
All thermostats set same (no setback)
Lights on and off
Run dishwashers on schedule
Run clothes washer and dryer on schedule
Activate showers on schedule
Open and close refrigerator and freezer doors
Human emulator (latent generator – in progress)
Electric resistance heaters to simulate other internal electrical loads

6. Energy-Efficient Test Homes
Net Monthly Energy Use*
Standard House 1,738 kWh
Retrofit House 1,377 kWh
Advanced House** kWh
*Average net consumption July 09 – Jan 10
**Includes reduction by solar generation
Monthly Energy Cost*
Standard House $146.60
Retrofit House $117.56
Advanced House $40.06
*Average cost July 2009 – Jan. 2010
Using Local Utility’s Residential Rates and TVA Generation Partners Solar Credit on Advanced House
Three houses built for comparison with same square feet automated to replicate family of four.
House 1 (Builder House) Cost: $250,000
This house represents a typical house (2,400 sq ft) currently built in the Tennessee Valley. It incorporates local building codes and standards and serves as a control against which the other homes are compared.
House 2 (Retrofit House) Cost: +$10,000 for retrofits described below
Same construction as House 1, but retrofitted with energy efficiency technologies that an existing homeowner could add. Major retrofits include: low-e, gas-filled windows; sealed, insulated attic; 100% CFL; smaller (3 ton versus 4 ton), higher SEER (16 versus 13) heat pump; and heat pump water heater.
House 3 (Near Zero Energy House) Cost: +$35,000 from base house including PV without any incentives
Built using more advanced construction technologies to make it as efficient as possible. Home characteristics include: 2.5 kW photovoltaic panels; solar water heating; 2X6 advanced framing; air tight construction; triple pane windows; R-48 spray fiberglass ceiling insulation; single HVAC system (2 ton), SEER 16 heat pump; 100% CFL; and Energy Star appliances.

7. House 1: Builder House (HERS 85)
TVA Near Zero Energy High Performance Homes
House 1: Builder House (HERS 85)

8. House 1 – Builder House (HERS 85)
Cost: $250,000
This house represents a typical house (2,400 square feet) currently built in the Tennessee Valley and serves as a control against which the other homes are compared
Incorporates local building codes and standards and is projected to use slightly less energy than a new house built to the International Energy Conservation Code (IECC)
“All electric” upgrade
Two SEER 13 heat pumps total tons
5.7 Air Change per Hour (ACH) @ 50 Pascal

9. House 2: Retrofit House (HERS 66)
TVA Near Zero Energy High Performance Homes
House 2: Retrofit House (HERS 66)

10. House 2 – Retrofit House – HERS 66
Cost: +$10,000 from base house for retrofits described below
Same construction as House 1 (Builder House), but retrofitted with energy efficiency technologies that an existing homeowner could add to improve efficiency
Major retrofits include: low-e, gas-filled windows; sealed, insulated attic; 100% CFL; smaller (3 ton versus 4 ton), higher SEER (16 versus 13) heat pump; and heat pump water heater
Projected to use two-thirds of the energy of a new house built to code
Blower door test -
3.4 ACH at 50 Pascal

11. House 2 – Retrofit House – HERS 66 Envelope
Slab construction - with 1’ X 24” perimeter insulation
High performance windows U-value of 0.34 and SHGC of 0.33
Windows installed with panned flashing and weather-lapped flashing tapes
Window sash replacement to lower U values and SHGC
Attic cathederalized with spray foam and spray Fiberglas and sealed (i.e. becomes conditioned space.)
Whole house air tightening package and addition of mechanical ventilation (one or both supply ventilation with bath exhaust)
Sealing/insulating knee walls in the bonus room
Ducts inside the conditioned space

12. House 2 – Retrofit House – HERS 66 Technologies
HVAC
One 3 ton SEER 16 heat pump with ECM indoor fan motors and zone dampers
Kitchen exhaust fan ducted to the outside
Duct sealing
Ducts located in sealed (semi-conditioned) attic
Electrical
Energy efficient lighting fixtures with 100% fluorescent
Energy Star appliances
High efficiency office vs. lower efficiency
High efficiency entertainment center vs. lower efficiency
Plumbing
Heat Pump Water Heater

13. House 2: Heat Pump in Cathedralized Attic

14. House 2: Hybrid – Heat Pump Water Heater

15. House 3: NZEH – Big Step House (HERS 32)
TVA Near Zero Energy High Performance Homes
House 3: NZEH – Big Step House (HERS 32)

16. House 3: NZEH – Big Step House – HERS 32
Cost: +$35,000 from base house including PV without any incentives
Built using the latest in construction technologies to make it as efficient as possible and still provide excellent curb appeal
Home characteristics include: triple pane windows; R-48 spray fiberglass ceiling insulation; single HVAC system (2 ton), SEER 16 heat pump; 100% CFL; and Energy Star appliances
Employs photovoltaic panels and solar water heating to help make it a near zero-energy house
Projected to use one-third the energy of a "code“ house
Blower door test Pascal

17. House 3: NZEH – Big Step House – HERS 32 Envelope
2 X 6 Advanced framing air tight construction using flash (foam) and sprayed spider (fiberglass) and structural insulating sheathing with taped seams
High performance triple pane windows U-value of 0.12 and
SHGC of 0.30
Windows installed with panned flashing and weather-lapped
flashing tapes
Slab perimeter insulated with 2 inch foam
R-48 spray fiberglass ceiling insulation (conventional vented
attic) and radiant barrier on roof deck

18. House 3: Structural Insulated Sheathing

19. House 3: Spray Foam Adds R-Value and Air Barrier

20. House 3: NZEH – Big Step House – HERS 32 Technologies
HVAC
Single HVAC system (2 ton) SEER 16 heat pump with ECM fan motor and variable speed compressor. System has zone dampers serving both floors
Ducts and indoor coil inside the conditioned space
Transfer ducts in each bedroom
Mechanical ventilation with a motorized damper connected to the central air distribution system and controlled with an energy recovery ventilator exhausting three baths and kitchen, and supplying the three bedrooms and great room
The supply outlets positioned at high interior walls aimed toward the exterior walls in each room

21. House 3: NZEH – Big Step House – HERS 32 Technologies
Electrical and Appliances
House will be wired with three kill switches, entertainment system, home office and whole house, with ORNL
Feed back meter will be wired into the house showing in the kitchen the whole house energy consumption real time
Energy efficient lighting fixtures with 100% fluorescent
Energy Star appliances
Photovoltaics kW of PV is installed on the roof. The system is grid connected through TVA Generation Partners program
Plumbing
Drainback solar domestic water heating system is installed
Heat recovery from grey water*
Heat recovery from dryer vent*
Heat recovery from dishwasher*

22. House 3: Solar Drainback Tank

23. House 3: Solar Storage Tank and HEX
When water drains it goes into tank when its not pumped.

24. House 3: Robo Refrigerator

25. House 3: PVs and Solar Water Heating

26. Monitoring and Occupancy Simulation
TVA Near Zero Energy High Performance Homes
Monitoring and Occupancy Simulation

27. Monitoring and Occupancy Program
Limited winter data
Full monitoring and occupancy simulation started June 1, 2009
ORNL and EPRI working on the simulation details
Blower door tests
House 1 – Pascal
House 2 – Pascal
House 2 – Pascal

28. Electric Bills July 2009 – January 2010

29. kWh Usage July 2009 – January 2010

30. Solar Generation Summary

31. Generation Partners Solar Credit

32. Builder House Energy Breakdown - January 2010

33. Retrofit House Energy Breakdown - January 2010

34. NZEH Energy Breakdown - January 2010

35. Key Takeaways
While data is still be collected for the first year, information suggests making sure you have a good air barrier on a house is key, in particular:
Ducts inside the conditioned space
2 X 6 advanced framing ensures air tight construction
Utilizing flash (foam) and sprayed spider (fiberglass)
For new construction, consider having houses solar ready (proper orientation, etc.)
Possible modifications being considered for next year (FY 2011) include:
House 3: Considering geothermal system change out
House 2: Considering change to variable refrigerant flow heat pump in air conditioned space (ductless)
House 1: Will remain as control house
Also will look more at demand response activities
An interim report on the TVA energy efficiency homes research project to be released Summer 2010
-Also consider having houses solar ready (i.e. proper orientation - within 20 degrees of due south, etc.)

36. Questions David Dinse Project Manager, Environment and Technology
Tennessee Valley Authority
(423)