Energy efficiency ratio. The standard rating point is 95 degrees F outdoors with 80 degrees F dry bulb and 67 degrees F wet bulb indoors. Because it reflects performance on a hot afternoon, EER is the better guide to peak electrical demand, and utilities and hot-climate codes often specify it alongside SEER. EER equals COP times 3.412.
Rebate needs 12.5 EER as well as the SEER, and that two-stage unit only makes 12.2 at 95.
Also heard as
- energy efficiency ratio
Related terms
SEER
Seasonal energy efficiency ratio: an air conditioner's cooling output over a typical season divided by its electricity use.
COP
Coefficient of performance: heat moved or delivered for each unit of energy put in, with both measured in the same units.
Ton
A unit of cooling capacity equal to 12,000 Btu per hour, the heat needed to melt a ton of ice in a day.
RTU
Rooftop unit: a packaged air conditioner, often with gas heat, that sits on a roof curb and ducts straight down into the building.