MRCOOL MDU18048060 4 to 5 Ton 18 SEER MrCool Universal Central Heat Pump/AC Split System - Upflow/HorizontalMRCOOL MDU18048060 The 4 to 5 Ton 18 SEER MrCool Universal Central Heat Pump Split System is one of the most high performing, versatile, and simple heating and cooling products available from the industry today. This is a central heat pump that can cool better than most air conditioners, heat better than virtually any other heat pump, compete with traditional furnaces in cold weather, and reduce energy consumption thanks to its sophisticated internal