Air Conditioning

SEER, EER and COP: Three Terms You Should Know Before You Shop

When Tulsa-area homeowners search for an efficient air conditioner to combat this summer’s heat, they will be confronted with three acronyms: SEER, EER and COP, often given in air conditioning sales literature without explanation. To find the best value for your home, make sure you understand the HVAC terms: Seasonal Energy Efficiency Ratio, Energy Efficiency Ratio, and Coefficient of Performance (SEER, EER and COP) before any purchase.

SEER, EER and COP: Three Terms You Should Know Before You Shop

SEER, EER and COP: Three Terms You Should Know Before You Shop


If you are considering a heat pump to cool and warm your Broken Arrow home, the COP will be an important measure. Mechanical devices such as heat pumps should have a COP of at least three, though the range can be two to four. Higher COP means greater efficiency.


Of SEER, EER and COP, EER is the most involved calculation. EER is a ratio of the cooling energy coming from a window air conditioner and the electricity used to operate the air conditioner. A high EER means the room air conditioner will save you more money on your electrical bill than a machine with a low EER.

If a sales person tries to dazzle you about the virtues of a particular unit, just mention that your EER is calculated as British Thermal Units (BTUs) divided by Watt-hours. Your knowledge is your best defense against distracting sales talk.


With SEER, EER and COP, Seasonal Energy Efficiency Ratio (SEER) is the only measure to calculate costs for an entire season. This allows you to estimate electricity costs for your Broken Arrow home when shopping for, and comparing, various central air conditioners.

The higher a central air conditioner’s SEER, the more efficiently the machine will cool your Broken Arrow home. Look for numbers of 13, the current minimum allowed by regulation, or higher. While you can find central air conditioners with SEERs into the 20s, their expense may not support your investment. Take comfort, though—a 13 SEER unit is 30 percent more efficient than a 10 SEER unit.

For help understanding how SEER, EER and COP will affect your central air conditioner purchase for your Tulsa-area home, contact us at Air Assurance.

Our goal is to help educate our customers in the Tulsa and Broken Arrow, Oklahoma area about energy and home comfort issues (specific to HVAC systems). 

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