If maximum performance and efficiency are key, look no further than our Evolution™ System heat pump. This ENERGY STAR^® qualified ductless system has up to a 28.5 SEER2 rating when paired with the 619PHB High Wall Even when temps drop to as low as -22° F outside, your interior environment stays cozy (when properly sized and matched with specific indoor units). Powerful yet extremely quiet, our best ductless outdoor solution delivers results.