US establishes new efficiency standards for residential central air conditioners

Following a public comment period until mid October, the United States Department of Energy (DOE) reaffirmed efficiency standards for residential furnaces, central air conditioners and heat pumps that are manufactured in or imported into the United States at the levels already established by a June 2011 direct final rule.

The rule establishes regional energy conservation standards for the North, South, and Southwest regions of the United States applicable as of 1 January 2015:

Product Class	National Standards	Southeastern Region Standards	Southwestern Region Standards
Split-system air conditioners	SEER=13	SEER = 14	SEER = 14 EER = 12.2 for units with a rated cooling capacity less than 45,000 Btu/h EER = 11.7 for units with a rated cooling capacity equal to or greater than 45,000 Btu/h
Split-system heat pumps	SEER= 14 HSPF=8.2	SEER = 14 HSPF = 8.2	SEER = 14 HSPF = 8.2
Single-package air conditioners	SEER= 14	SEER = 14	SEER = 14 EER = 11.0
Single-package heat pumps	SEER= 14 HSPF=8.0	SEER = 14 HSPF = 8.0	SEER = 14 HSPF = 8.0
Small-duct, high-velocity systems	SEER= 13 HSPF=7.7	SEER = 13 HSPF = 7.7	SEER = 13 HSPF = 7.7
Space-constrained products – air conditioners	SEER=12	SEER = 12	SEER = 12
Space-constrained products – heat pumps	SEER =12 HSPF=7.4	SEER = 12 HSPF = 7.4	SEER = 12 HSPF = 7.4

* SEER is Seasonal Energy Efficiency Ratio; EER is Energy Efficiency Ratio; HSPF is Heating Seasonal Performance Factor; and Btu/h is British thermal units per hour.

The rule also amends energy conservation standards when the equipment is in standby mode and off mode.

Hydrocarbons soon in the US?

The use of hydrocarbons in air conditioning and heat pumps is currently not acceptable in the US. Meanwhile, a long awaited and imminent approval under the US Significant New Alternatives Policy (SNAP) programme of four hydrocarbons, namely isobutane, propane, HCR-188C (R441a), and HCR-188C1 as acceptable refrigerants in household and light commercial applications may be expected to kick start thinking about their potential in other applications such as air conditioning.

Background

In January 2010, the Air-conditioning, Heating, and Refrigeration Institute (AHRI), American Council for an Energy-Efficient Economy (ACEEE), Alliance to Save Energy (ASE), Appliance Standards Awareness Project (ASAP), Natural Resources Defense Council (NRDC), and Northeast Energy Efficiency Partnerships (NEEP) submitted a joint comment to DOE's residential furnaces and central air conditioners and heat pumps rulemakings recommending adoption of a package of minimum energy conservation standards for residential central air conditioners, heat pumps, and furnaces.

After analysing the industry recommendations, DOE issued a direct final rule amending the energy conservation standards for residential furnaces and central air conditioners and heat pumps on 27 June 2011.