XR15Up to 15.6 SEER2Up to 8.1 HSPF2 XL15Up to 15.6 SEER2Up to 8.1 HSPF2 XL17iUp to 17.2 SEER2Up to 8.1 HSPF2 XR14Up to 14.8 SEER2Up to 7.8 HSPF2 XR16Up to 16.2 SEER2Up to 8.1 HSPF2 XV18Up to 18 SEER2Up to 8.5 HSPF2 XV19Up to 19 SEER2Up to 9 HSPF2 XV20iUp to 20.5 SEER2Up to 8.7 HSPF2