What is SEER?
Every condensing unit, the core component of a central air condtioning or heat pump system, is given a SEER rating which is a measurement of its energy efficiency. The SEER rating is short for the Seasonal Energy Efficiency Rating. It lets consumers know just how efficiently the unit turns electricity into heating or air conditioning. The higher the SEER rating is, the more efficiently it uses electricity.
How is SEER Determined?
SEER is much like fuel efficiency in your vehicle. The further your car or truck can go on a gallon of gas, the more fuel-efficient it is. For a condensing unit, the more air conditioning or heating it can produce for the same amount of electricity, the more efficient it is. The reason it is called the “Seasonal” EER is that it is measured over an entire heating or air conditioning season. Technically speaking, SEER measures the heating or air conditioning output of a condensing unit in British thermal units, or Btu, during an entire heating or cooling season. It divides the output by the total input of electricity, measured in watt-hours during that period. The higher the unit's SEER rating the more energy efficient it is.
What SEER Ratings are Available?
In 2006, federal regulations were put in place that requires a minimum SEER rating of 13 of new central air conditioners and heat pumps. There are still units at work in homes with a SEER rating as low as 8. Manufacturers today make a product lineup that features a range of SEER ratings. The best selling models offer SEER ratings between 14 SEER and 18 SEER. The most efficient residential condensing units have a SEER rating or well over 20.
SEER and Cost
The more efficient a condensing unit is, the more it is likely to cost. As a rough estimate, with every 1 point increase in SEER, the unit will go up in cost by 8-10%, all else being equal (capacity, features, brand, etc.). Of course, the higher the SEER rating, the less energy it will use and the lower the energy cost will be. If an 8 SEER air conditioner is replaced by a 16 SEER model, energy use will be cut in half, and so will the cooling portion of the utility bill.
In warmer climates, choosing a unit with a higher SEER is a cost-effective decision. The time it takes to recoup the extra expense of a more efficient unit in the form of lower energy bills is known as the “payback period.” In warm climates, the payback period for choosing an 18 SEER central air conditioner over a 14 SEER model can be as little as 2-3 years.
SEER and Energy Star
The federal government began the Energy Star program as a way to identify energy-efficient products. Currently, for a condensing unit to meet Energy Star requirements it must be rated 14 SEER or higher along with an EER of 12.5. EER is the point in time Energy Efficiency Rating versus the SEER that measures seasonal average energy efficiency.
Today's condensing units continue to get more energy-efficient with each new generation of products. Homeowners welcome this due to the high and volatile cost of electricity. Higher efficiency is also attractive to many consumers because it means that their HVAC system is producing less greenhouse gas, reducing their impact on the environment. Knowing what SEER is and how it affects your energy bills and your lifestyle is an important part of choosing the right central air conditioner or heat pump for your home.