The Energy Star Rating for air conditioners is based of the EER. The Energy Efficiency Rating, or EER, is acquired by dividing the BTU output per hour by the Watts consumed in that period at a given temperature level of 95° F. It is an essential measurement of an air conditioner’s performance. The higher this ratio is, the better the system efficiency. All air conditioners are federally regulated and required to meet a minimum EER for certain BTU output capacities. Energy Star rated units must be 10% more efficient than the federal minimum as indicated in the table below.
The highest-efficiency systems typically cost more, but they may also qualify for a tax credit under government incentive programs on either or both state and federal levels. This can help mitigate a good portion of the extra up front expense and are usually inclusive of labor costs for intallation! Visit our Tax Credit Info page for a summary of the requirements for qualitfication and more information.
Consumers will also frequently see the SEER, or Seasonal Energy Efficiency Rating. This ‘energy score’ more accurately reflects the overall efficiency of a unit since it is calculated over a longer-term basis. The SEER will also always be higher than the EER for any given unit. Essentially the SEER gives you insight to the system’s overall efficiency, while the EER gives you the unit’s efficiency during peak performance periods. Both the SEER and the EER are important when considering buying an air conditioner unit.
|Capacity (BTU/hr)||Federal Standard EER, with louvered sides||ENERGY STAR EER, with louvered sides||Federal Standard EER, without louvered sides||ENERGY STAR EER, without louvered sides|
|< 6,000||>= 9.7||>= 10.7||>= 9.0||>= 9.9|
|6,000 to 7,999|
|8,000 to 13,999||>= 9.8||>= 10.8||>= 8.5||>= 9.4|
|14,000 to 19,999||>= 9.7||>= 10.7|
|>= 20,000||>= 8.5||>= 9.4|
|Casement||Federal Standard EER||ENERGY STAR EER|
|Casement only||>= 8.7||>= 9.6|
|Casement slider||>= 9.5||>= 10.5|
For units that also operate as a heat pump, you will also see the HSPF, or Heating Seasonal Performance Factor. This is merely the SEER when the unit is in heating mode. If you expect you will be using a heat pump in cooling mode more frequently, look for a unit with a high SEER. Conversely, If you expect you will be using a heat pump in heating mode more frequently, look for a unit with a high HSPF.
Keep in mind that if the temperature of your area often dips below 40°F it will likely be more cost effective to cool your space with a central air unit in the summer and a furnace in the winter instead of a heat pump. Heat pumps do have the added benefit of being one unit to install and maintain, but a potential buyer must consider the extra cost generally associated with these units in addition to the extra wear and tear on a system that is running year-round. Moreover, in these colder climates, the outside coils of a heat pump can collect ice, actually causing the unit to run in air conditioning mode for a while to melt them away.