The Lennox XP16 is a two-stage heat pump with an efficiency rating of up to 17.00 SEER and 9.50 HSPF. The XP16 is designed to run at low stage more than 80 percent of the time, resulting in even temperatures and higher efficiency. A precision-balance, direct-drive fan helps to keep sound levels as low as 74 dB. The unit's SmartHinge louver design allows quick access from all sides for easy maintenance while protecting the coil. The cabinet is constructed of heavy-gauge galvanized steel with a corrosion-resistant baked-on powder finish.