SEER stands for Seasonal Energy Efficiency Ratio, and it measures the annual energy consumption and efficiency of the unit’s cooling ability in typical day-to-day use. The higher the SEER value, the less energy the unit will use. Many older residential air conditioning systems in the U.S. may have a SEER number of 10 or less. The good news for homeowners in the market for a new air conditioner or heat pump is that current high-efficiency residential equipment can boast SEER values of 25 or higher. Higher SEER units typically cost less to run, which can save homeowners money on energy costs.