Understanding Air Conditioner Efficiency Ratings



Air conditioning annually consumes more than 6% of all the electricity produced in the United States, costing homeowners more than $29 billion annually. That’s why understanding your air conditioning system’s efficiency is a matter of common sense.

Your air conditioner makes your home cooler by moving heat from inside your home to the outside. The compressor motor uses most of the energy making this happen. Compared to the energy consumed by the compressor, your air condition system produces about 3 times the cooling power. But how efficient is your air conditioner?

Seasonal Energy Efficiency Ratio

The most common measure of efficiency is SEER, the Seasonal Energy Efficiency Ratio–you’ve likely seen the SEER mentioned on the bright yellow “EnergyGuide” stickers that are found on appliances such as refrigerators and water heaters, as well as air conditioners. SEER is a measure of how many BTUs a system produces while consuming one watt of electricity—the higher the SEER number, the more efficient the air conditioner. Just as ‘miles per gallon’ is used to compare car efficiency, SEER allows you to compare the energy efficiency of various AC units.

As of 2015, air conditioners sold in California must now have a minimum SEER rating of 14. However, higher efficiency units of 18 and even 26 SEER are available. But keep in mind, a higher SEER unit will not blow colder than a lower SEER unit. A high SEER rating means that the air conditioner will deliver the same cooling power for less money. For example, a 16 SEER system can save an estimated $2,000 in annual operating costs.

Other AC Efficiency Ratings to Consider

Depending on your climate, you may want to consider other efficiency rating measures. For example, in hot, dry climates, you should look at the Energy Efficiency Ratio (EER). The EER is calculated assuming a steady outside temperature of 95 degrees Fahrenheit, while SEER is calculated using a temperature range of 65 to 104 degrees Fahrenheit.

EER is a better standard to use in areas that tend to be very hot—95 degrees or higher—for long periods of time, as EER gives a sense of how well an AC works at peak operating conditions. On the other hand, if the average summer temperature in your area is between 80 and 90 degrees, then SEER will be more relevant for you.

If you live in a hot, humid climate, you need to consider how well a system can dehumidify indoor air. We perspire to provide natural cooling through the evaporation of perspiration from our skin. Drier air, up to a point, improves the comfort you experience indoors. Generally speaking, air conditioners are designed to create a 40% to 60% relative humidity in your home.

There’s No One-Size-Fits-All Efficiency Rating

There’s no ‘best’ SEER rating for everybody. Your individual AC operating habits, the size of your home, the condition of your home’s ductwork, and your personal savings goals all have a role in determining the optimal system efficiency choice for your air conditioning system.

If you have questions about how to select an air conditioner that’s ideal for your home, call the experts at Gilmore. We offer free consultations, and can perform the measurements and calculations necessary to find the unit that will save you the most money, while providing the level of comfort you desire.