Goodman GSXN4 | Air ConditionerThe best air conditioner is the kind you don’t have to think or worry about. The Goodman brand GSXN4 line of air conditioners deliver efficient cooling with a nominal 14.3 SEER2 and loaded with features designed to provide outstanding performance for years to come. It runs quietly and efficiently all year long as needed.SMARTCOIL™ TECHNOLOGY SMALLER IS SMARTERLong ago the HVAC industry determined that the combination of copper tubing and aluminum fins provided the most efficient transfer of thermal heat available.