Rated among the best for smart energy use. With a SEER of up to 20.00 and an HSPF of 10.00, the XP20 uses energy extremely efficiently without sacrificing comfort. This can mean several hundred dollars per year in energy savings. This product has been designated as one of the Most Efficient ENERGY STAR certified products in 2018. Products that are recognized as the Most Efficient of ENERGY STAR in 2018 prevent greenhouse gas emissions by meeting rigorous energy efficiency performance levels set by the U.S. Environmental Protection Agency.