THE PRODUCT:
Commercial central air conditioners (CACs) and heat pumps (HPs) (<65,000 Btu/hr) are nearly identical to typical residential CACs and HPs, but are designed to operate on 3-phase electric current rather than single-phase power. 3-phase Variable refrigerant flow systems (<65,000) are considered small commercial equipment. Commercial 3-phase CACs can either be "single package" systems, where the evaporator coil and the condensing unit are combined into a single physical unit, or "split systems," where the condensing unit is typically placed outdoors while the evaporator is indoors.
Commercial CACs and heat pumps include the smaller categories of 3-phase space-constrained products and small-duct, high-velocity (SDHV) products.
CACs and HPs (<65,000 Btu/hr) are a category of ASHRAE equipment.
THE STANDARD:
The current standards for commercial CACs and HPs took effect in 2017. The efficiency levels are equivalent to the levels in the 2013 version of ASHRAE 90.1. For split-system commercial CACs, the minimum cooling efficiency is SEER 13. For single-package CACs and all heat pumps, the minimum cooling efficiency is SEER 14. The heating efficiency standards for commercial HPs are HSPF 8.2 and 8.0 for split-system and single-package units, respectively.
In 2023, DOE updated the standards, with compliance required starting January 1, 2025. The amended efficiency levels are equivalent to the national standards for residential CACs (13.4 SEER2) and heat pumps (14.3 SEER2/7.5 HSPF2 for split systems and 13.4 SEER2/6.7 HSPF2 for packaged units). However, the standards for commercial space-constrained products and SDHV products are more stringent than the standards for the residential equivalents.
**The cooling energy efficiency metric, seasonal energy efficiency ratio (SEER) is the total space cooling required during the cooling season, expressed in Btu, divided by the total electrical energy consumed by the air conditioner or heat pump system during the same season, expressed in watt-hours.
The heating energy efficiency metric, heating seasonal performance factor (HSPF) is the total space heating required during the heating season, expressed in Btu, divided by the total electrical energy consumed by the heat pump system during the same season, expressed in watt-hours.
KEY FACTS:
Technology options for improving the efficiency of 3-phase CACs and HPs include higher efficiency compressors, improved condenser and evaporator coils, and higher efficiency fan motors and fan blades.