This rulemaking pertaining to test procedures for Central Air Conditioners and Heat Pumps proposes revisions to the test methods to improve test repeatability and reduce the test burden of the test procedure. These proposals would be required for demonstration of compliance with the current energy conservation standards starting 180 days after publication of the final rule. These proposed amendments include, establishing a delay time prior to off mode power measurements for some systems; limiting the internal volume of refrigerant pressure measurement lines; requiring bin-by-bin EER and COP interpolations for all variable speed units; requiring that the official test for a unit using the outdoor enthalpy method as a secondary check of capacity be the test without the outdoor enthalpy apparatus connected.

DOE is also proposing test procedure amendments to improve field representativeness. These proposals would take effect coincident with updated energy conservation standards and would be part of a new Appendix M1. The proposed Appendix M1 include, new higher external static pressure requirements for all units, including unique minimum external static pressure requirements for certain kinds of products; new default fan power values for rating coil-only units; revisions to the heating load line in the calculation of HSPF; and amendments to the test procedures for variable speed heat pumps to allow better representation of their low-ambient-temperature performance, including an optional 5 °F heating mode test.