How to Understand Air Conditioner Ratings

How to Understand Air Conditioner RatingsShopping for a new central air conditioner lacking a familiarity with air conditioner ratings is like going hiking barefoot. You’re not going to get very far. Ratings that show the cooling efficiency of an air conditioning system (in effect, how well the system converts electricity into cooling) will help you get the right A/C for your San Diego-area home.

The most common residential central cooling system in Southern California (and the U.S. as a whole) is the split-system A/C or heat pump. It has one component (the air handler/evaporator coil) inside the house and another (the condenser/compressor) outside. The main efficiency rating applied to split-systems is Seasonal Energy Efficiency Ratio (SEER). The number — running from 13 to 25 in the U.S. — is calculated by dividing cooling output by the electrical power that goes into the equipment. The higher the number, the more efficient the A/C or heat pump.

Manufacturers in California are prohibited from selling split-system A/Cs with SEER numbers below 14. Heat pump A/Cs must have at least SEER 15. In order to qualify for the federal government’s energy-efficiency credential, the Energy Star, a split system air conditioner and heat pump must boast SEER 15 or above.

The higher efficiency does cost money, however, with incremental increases in SEER amounting to hundreds of dollars. A homeowner shopping for a new central A/C should consider how much use they expect to get out of their new cooling system. A family that runs the A/C constantly and expects to live in the same home for the foreseeable future should consider investing in a high-SEER A/C or heat pump. Over time, the lower operating costs will pay for the extra upfront cost. However, someone who doesn’t plan to stay in the same home more than a few years, or is out of town a lot, is probably better off with a low-end SEER system. Consult with your trusted HVAC contractor before making a decision.

For help understanding air conditioner ratings, or to discuss upgrading your San Diego home’s cooling system, please contact us at Sherlock Heating & Air Conditioning.

Our goal is to help educate our customers in the greater San Diego and San Marcos, California area about energy and home comfort issues (specific to HVAC systems).

Credit/Copyright Attribution: “openclipart-vectors/pixabay”

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  • Great information! I agree that the better the system the more the price. However, when you are purchasing a big ticket item like this, it’s best not to skimp. Instead, get an AC you are going to be able to use with little fuss for a long time and that also can save you money!

    • Glad this was helpful!

  • Spend more upfront on a high quality, energy efficient unit and the product will pay for itself in energy savings over the course of it’s life. Not to mention it will most likely have a longer life than the less expensive units.

    • Thanks, Harry!


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