Frequently Asked Questions
What is SEER? EER? HSPF?
Seasonal Energy Efficiency Ratio (SEER)
Most commonly used to measure the efficiency of a central air conditioner. The higher the SEER, the more efficient the system. SEER measures how efficiently a cooling system will operate over an entire season. In technical terms, SEER is a measure of equipment the total cooling of a central air conditioner or heat pump (in Btu) during the normal cooling season as compared to the total electric energy input (in watt-hours) consumed during the same
Energy Efficiency Ratio (EER)
A measure of how efficiently a cooling system will operate when the outdoor temperature is at a specific level (95oF). The higher the EER, the more efficient the system. In technical terms, EER is the steady-state rate of heat energy removal (i.e. cooling capacity) by the product measured in Btuh divided by the steady-state rate of energy input to the product measured in watts. This ratio is expressed in Btuh/watt. Both SEER and EER are included in the ENERGY STAR® specification because each rating indicates the energy efficiency of the product under different operating modes. SEER rating more accurately reflects overall system efficiency on a seasonal basis and EER reflects the system’s energy efficiency at peak day operations. Both ratings are important when choosing a product.
Heat Seasonal Performance Factor (HSPF)
The most commonly used measure of a heat pumps heating efficiency. The higher the HSPF, the more efficient the heat pump. In technical term, HSPF represents the total heating output of a heat pump (including supplementary electric heat) during the normal heating season (in Btu) as compared to the total electricity consumed (in watt-hours) during the same period. HSPF is based on tests performed in accordance with AHRI 210/240 (formerly ARI Standard 210/240).













