2013 Building Energy Efficiency Standards

1. 2013 Building Energy Efficiency Standards Residential Zoned AC Discussion August 18, 2011

2. Zoning Proposal Status • CEC Staff Proposal • Originally sponsored by the California Statewide Utilities Codes and Standards Program as a Codes and Standards Enhancement (CASE) study • CASE study authors • Bruce Wilcox, P.E. • John Proctor, P.E. Proctor Engineering Group, Ltd. • Rick Chitwood, Chitwood Energy Management, Inc

3. Agenda Importance of AC in California California cooling climate Other AC improvements Why zoning improvements Magnitude of problem and savings Laboratory testing of bypass Review of field studies Zoning Proposal Recap 3

4. Why Air Conditioning is Important

5. California Cooling Climate • Features • high daytime dry bulb temperatures • big solar gains every day • low relative humidity • low nighttime temperatures • Results • sensible capacity and EER at high outdoor temperature are important • dehumidification is not useful

6. Staff Proposed AC Improvements • Higher solar reflectance roofing • Lower SHGC windows (from 0.4 to 0.25) • Increased wall insulation in all zones • Insulation quality inspections • Whole house fans • Roof deck insulation • Increased attic duct insulation • Mandatory AC minimum air flow • Improved zonal control systems

7. Why Zoning Improvements • There are a lot of unimproved zoning systems in new California homes • Unimproved multi-zone ducted systems have significantly lower energy efficiency • Laboratory tests by Carrier • Field tests in new California homes • Many alternative zoning approaches can deliver equivalent efficiency • Zoning system improvements are cost effective.

8. Zoning Code Change Philosophy • Multi-zone systems are fine • But • Multi-zoned systems should deliver the same (or better) energy efficiency as single zone systems)

9. 12% of the Ducted Systems are Dampered Multi-Zoned

10. Dampered Multi-Zone Systems have Low CFM per Ton andHigh Cooling Fan Power per CFM

11. Average Energy Impact • In typical homes with dampered multi-zone systems: • Air Conditioning SEER and EER are degraded by 17% • Furnace AFUE is degraded by 4.4%

12. Effect of Bypass and Zoning Flow in SEER Terms

13. Eliminate Bypass and Obtain a Minimum Airflow

14. Carrier Laboratory Testing of Bypass

15. Carrier ASHRAE Paper Literature Review • Papers cited by AHRI to support the zoning performance credit • “All but one study employed variable or two speed equipment.” • “… the homes were unoccupied and zone separation (closed doors) was maintained throughout testing caused energy losses to be minimized. Thus, the documented field studies could be considered a ‘best case scenario’ in terms of energy savings.”

16. Code Change Proposals • Eliminate bypass ducts • Mandatory airflow and fan Watt verification in all zonal cooling modes(the airflow and Watt draw mandate also apply to single zoned systems) • Delete the current zonal AC performance compliance credit.

17. Chitwood’s Redding, California Showcase Home With 4 zone ducted AC system that meets the proposed requirements.