SEER, AFUE and HSPF are all measures of energy efficiency. Air conditioners may look similar, but their Seasonal Energy Efficiency Rating (SEER) can vary widely. Higher SEER numbers save more money spent on electricity. A 13 SEER air conditioner, the EPA "current minimum standard", uses 23% less energy than a 10 SEER unit (EPA standard up until Jan. 2006). Even though 13 SEER is the minimum efficiency available, we currently offer a line of air conditioners that start at 13 SEER and go all the way up to a 21 SEER . Depending on your average usage, higher SEER air conditioners can significantly reduce your electric bill. Heat pumps have SEER ratings like air conditioners and Heating Seasonal Performance Factor (HSPF) ratings for measuring heating efficiency. Higher HSPF ratings mean greater energy savings. The HSPF scale range is 7.5 to 13.0. Today's new high-efficiency furnaces can save up to 50% in operating costs over a ten-year-old furnace. Many 1990 and earlier model furnaces have Annual Fuel Utilization Efficiency (AFUE) ratings of 65% or less. The minimum AFUE rated furnace that can be sold in the United States as of May 1, 2013 is 80% in southern states and 90% in northern states. Our current product offering starts at this minimum AFUE rating and goes all the way to a very efficient 98.3% AFUE rating. Depending on your average usage, higher AFUE rated furnaces can significantly reduce your gas bill.