Commercial HVAC Unit Manuals & Owner Guides

Commercial HVAC efficiency ratings

SEER2 / EER2 / HSPF2

Used for commercial units under 65,000 Btu/h (typically three-phase). SEER2 is seasonal cooling efficiency, EER2 is efficiency at 95 °F, and HSPF2 is seasonal heat pump heating efficiency.

IEER

Integrated Energy Efficiency Ratio, used for units of 65,000 Btu/h and larger. It weights efficiency at 100%, 75%, 50% and 25% load to reflect real operating hours.

EER

Full-load cooling efficiency at standard rating conditions; important for peak demand.

COP

Heat pump heating efficiency at a given outdoor temperature (47 °F and 17 °F are standard rating points).

Packaged rooftop units vs. split systems

Packaged units house the compressor, coils, fans and any heat section in one cabinet, usually on a roof curb, which keeps refrigerant piping inside the factory-built unit and simplifies service access. Split systems put the condensing unit outdoors and the coil and air handler or furnace indoors, and their ratings apply only to specific certified matches of components.

The move to lower-GWP refrigerants

Under the U.S. EPA's Technology Transitions rule, new residential and light commercial air conditioning and heat pump equipment is moving away from R-410A to refrigerants with a global-warming potential below 700, most commonly R-454B and R-32. These are A2L (mildly flammable) refrigerants, so new equipment includes leak detection and requires technicians trained in A2L handling.

Commercial HVAC Unit FAQ