The Department of Energy (DOE) is directed by the Energy Policy and Conservation Act to establishing minimum efficiency standards for various consumer products; including central air conditioners and central air conditioning heat pumps. SEER and EER is a rating system created to measure the efficiency of an air conditioner or heat pump.

Both ratings should be considered in choosing cooling products. The rating is a ratio of the cooling output divided by the power consumption and measures the cooling performance of the system. The Federal government developed an ENERGY STAR program for high efficiency central air conditioning systems that in order to qualify must have a SEER of at least 14.

SEER rating

SEER stands for Seasonal Energy Efficiency Rating and is basically a number describing where an air conditioning unit falls on the efficiency scale, in regards to power consumption. It is calculated using the ratio of output cooling (Btu/hr) to input electrical power (watts).

Unlike EER, which is evaluated using a specific operating condition, SEER represents the overall expected performance of a unit, in a given location, for a typical year’s weather. It is measured using the same indoor temperature, but with an outdoor temperature range from 65 to 104 degrees fahrenheit.

The easiest way to think of a SEER number is by comparing it to how many miles per gallon a specific car is capable of handling. You might consider buying a Prius instead of a Hummer if gas prices is an issue. The same goes for a/c units – you would buy a unit with a higher SEER rating if you want a lower energy bill.

Concerning residential air conditioners, as of January 23rd 2006, new units sold in the United States by law must have a SEER rating equal to or greater than 13. Before 2006 the minimum standard was 10 (NOTE: A unit with a SEER rating of 13 is 30% more efficient than a unit with a SEER rating of only 10).

Homeowners are not required to upgrade to a higher efficiency model, but with an average lifespan of about 15 to 20 years low efficiency units (at least the ones below SEER 13) will eventually go away completely.


EER is the abbreviation for Energy Efficiency Ratio and unlike SEER it does not take into consideration the time of year, but rather the system’s energy efficiency at a specific operating point. Just as SEER it is the ratio of output cooling (Btu/hr) to input electrical power (watts).


While a consumers wallet is the number one deciding factor in purchasing a new unit there are some things a consumer should know about higher SEER ratings and the benefits of purchasing them.

If money is hard to come by Laponica Refrigeration recommends you at least try to purchase a SEER 16 unit. The savings you gain at that level will help pay for the extra cost in a minimal amount of time.

A unit with a SEER rating of higher than 16 may not necessarily provide the savings necessary to account for the extra cost, but they do tend to provide extra comfort accessories such as a variable fan speed on your indoor unit.

A variable fan speed keeps a more stable temperature in your house. In a standard air conditioner unit your indoor temperature will vary by approximately 3 degrees between cut-in and cut-out of the unit. Let’s say it is hot outside and you set your thermostat to 75 degrees. Your unit will cut off once it reaches 75 degrees. A normal unit will not turn back on before it reaches 78 degrees. This keep your house +/- 3 degrees from what you set it at. With a variable fan speed this does not happen and you end up with a more stable temperature inside your house.


United States of America. Department of Energy.ENERGY-EFFICIENT AIR CONDITIONERS: NEW STANDARDS COMING IN 2006 . Web.

. “Seasonal energy efficiency ratio.” Wikipedia The Free Encyclopedia. Wikipedia, 13 2012. Web. 26 Nov 2012. . SW – NEW ORLEANS A/C TERMINOLOGY