Understanding A/C Efficiency Ratings

With the hot and humid weather of the Southwest Florida area, the overall efficiency of your air conditioning system can make a significant difference in your cooling costs during the summer. By understanding what each of the basic A/C efficiency ratings represent, you will be able to make an informed decision when purchasing a new air conditioning system or heat pump.


The energy efficiency ratio, or EER, represents the cooling capacity of an air conditioning system measured in British thermal units or BTUs, divided by the amount of electrical power required to provide that cooling measured in kilowatt-hours. This rating represents the amount of energy used to provide cooling during peak conditions, such as the hottest days of the year, and is not the most reliable estimate of how the system will perform over time. A system with a higher EER will be more efficient, and today’s best systems feature EER ratings of over 16.


The seasonal energy efficiency ratio, or SEER, is a long-term measurement of the cooling efficiency of an air conditioning system. It is a ratio of the cooling output provided for a full season in BTUs, divided by the amount of energy, in kilowatt-hours, required to power the system. It is a better representation of how the system will perform in a variety of weather conditions, and, like the EER rating, higher is better. Today’s federal standards require A/C efficiency ratings of 13 or 14 SEER depending on location, and the best systems offer SEER ratings of over 23.


The heating seasonal performance factor, or HSPF, measures the amount of heat provided during a heating season,in BTUs, divided by the power required in kilowatt-hours. This rating is applicable to heat pumps, which can provide both heating in the winter and cooling in the summer. A higher HSPF is represents greater efficiency, and the most efficient systems feature a rating of up to 13 HSPF.

For more information about A/C efficiency ratings, talk to our cooling experts at Conditioned Air. We serve the Southwest Florida area, including Ft. Myers and Naples.

Compliance Settings
Increase Font Size
Simplified Font
Underline Links
Highlight Links