21 SEER: Quad-Zone Ductless Mini Split AC - Heat Pump: With a 54000 BTU total Cooling / HEATING Capacity, this Quad Zone INVERTER mini split air conditioner can cool 4 separate zones (12000 + 12000 + 12000 + 18000) for a total coverage area of 2500 ft² (550 ft² + 550 ft² + 550 ft² + 850 ft² areas). 21 SEER cooupled with Advanced Inverter technology provides the benefits of low operation temps, rapid cooling / heating as well as maximum energy efficiency.