The MRCOOL® 4th Generation DIY 36K BTU, 18 SEER Ductless Heat Pump is one of the most powerful single-zone systems offered in the DIY Series. This complete system has the heating and cooling performance to cover an area up to 1500 sq. ft while still being able to achieve an 18 SEER efficiency rating. The MrCool Pre-Charged Quick-Connect Line Set that makes connecting refrigerant piping as simple as turning a few wrenches. It is also equipped with up to six operating modes, which include AUTO, HEAT, COOL, FAN-ONLY, DRY (dehumidification), and SLEEP.