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. All of this performance is within a system that can be easily installed by a homeowner with a few hand tools thanks to the patented MrCool Pre-Charged Quick-Connect Line Set thatmakes connecting refrigerant piping as simple as turning a few wrenches.