Common Sense Saves Energy Dollars with Facility Air Conditioning

Seasonal Energy Efficiency Ratio (SEER)

As air conditioning equipment nears the end of its useful life, building owners and engineers are faced with the task of specifying and purchasing new, energy efficient equipment. An understanding of the United States Department of Energy’s (USDOE) Seasonal Energy Efficiency Ratio is necessary if the correct choices are to be made.

The Seasonal Energy Efficiency Ratio (SEER) rates each model of air conditioning equipment based on the amount of energy consumed while providing a specific amount of cooling. The SEER is an improvement of the EER (Energy Efficiency Ratio) used in the past, with the new method measuring the energy use over a wide range of operating conditions.

The SEER is calculated by using the old EER and including a part-load factor. The resulting number, ranging from a low below 9.0 to a high of over 13.0, advises the purchaser of the comparable cost of operation between competing models. The higher the number, the more efficient the unit.

USDOE regulations require an increase in the SEER rating of equipment manufactured after January 2006.

According to USDOE estimates, a 10-ton high-efficiency rooftop unit meeting the new standard of 13.0, compared to a currently installed standard unit with a SEER of 8.9, would save the owner $1,950 over the anticipated 15-year life of the unit. This calculation is based on relative purchase costs of the two units and energy consumption based on a national average of $0.08/kWh.