What Does the SEER Rating on Central Air Units Mean?

Central air conditioner units carry a SEER rating indicating energy efficiency.

New central air conditioner units have an energy guide label that lists the unit's Seasonal Energy Efficiency Ratio, or SEER. The SEER rating indicates how well that air conditioner utilizes the energy it consumes.

History

Air conditioners today are more energy-efficient than those manufactured years ago. The best modern air conditioners use 30 percent to 50 percent less energy to cool a home than air conditioners in the 1970s. In fact, a new air conditioner can save up to 20 percent to 40 percent of the energy that a 10-year-old unit costs to run, according to the U.S. Department of Energy (DOE).

Efficiency

Scientists measure the heat in inside air using British Thermal Units (Btu). The SEER rating on central air conditioner units "lists how many Btu per hour are removed for each watt of power it draws," according to the DOE.

Significance

DOE developed the calculation for the SEER rating to match actual operating conditions. All ducted central air conditioning systems that produce up to 65,000 Btus are SEER-rated. The SEER calculation takes into consideration all "electricity used by the indoor blower motor, outdoor fan motor, and compressor when matched with a specific indoor coil," according to the Louisiana Department of Natural Resources.

References

• National Renewable Energy Laboratory: Energy-Efficient Air Conditioning
• Louisiana Department of Natural Resources: A B C-1 2 3
• U.S. Department of Energy: Energy-Efficient Air Conditioners: New Standards Coming in 2006