Hansberger Refrigeration Blog: Your AC Repair Resource

SEER, EER and COP: Understand These Terms Before You A/C Shop

The terms SEER, EER and COP are used to define the efficiency of an air conditioning system. They are important indicators of how much energy an A/C uses, and are a good way to gauge what products will best reduce energy usage in your home. 

Coefficient of Performance (COP)SEER, EER and COP: Understand These Terms Before You A/C Shop

COP is a measure of the efficiency of your air conditioning compressor. It is calculated by dividing the cooling output energy with the input electrical energy (using the same units). Typical values for COP will range between 2 and 4, with the higher the value the more efficient the compressor. A COP of 4 means that the air cooling energy from the air conditioner will be four times more than the input energy, so for 1 kW of input power you get 4 kW of cooling power.

Energy Efficiency Ratio (EER)

The energy efficiency ratio uses units that are more familiar; it measures the cooling energy generated in BTU/hr and divides it by the input electrical power measured in watts. This ratio is measured at a specified indoor temperature (80 degrees F), outdoor temperature (95 degrees), and relative humidity of 51 and 40 percent, respectively. The higher the EER, the better the unit; typical values range between 10 and 12.

There is a direct relationship between EER and COP, in that the EER equals the COP multiplied by 3.41.

Seasonal Efficiency Ratio (SEER)

While the EER is measured at a specified temperature, the SEER is measured over a range of outdoor temperatures and is designed to produce a figure that is more representative of the performance of an air conditioner over the variety of temperatures a homeowner experiences during a season. This is the main efficiency benchmark that the federal government uses as a standard for new A/Cs and heat pumps. In Arizona, most types of air conditioners and heat pumps are required to have a minimum SEER of 13, though that minimum is expected to rise to 14 next year.

If SEER, EER and COP still seem confusing, please let us know at Hansberger Refrigeration and Electric Company. We have been operating in the Yuma area since 1952.

Our goal is to help educate our customers in Yuma, Arizona about energy and home comfort issues (specific to HVAC systems).  For more information about SEER and other HVAC topics, download our free Home Comfort Resource guide.

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