Introducing the MRCOOL E Star DIY 3rd Gen 18k BTU 20 SEER Ductless Mini-Split Heat Pump. These are ductless mini-split heat pumps with enhanced WIFI engineered to make setup not only quick and easy, but the. MRCOOL DIY E Star Series is flexible enough to be installed virtually anywhere without requiring specialized tools or expensive equipment. The 18,000 BTU unit is 20 SEER and designed to heat and cool up to 750 square feet efficiently and effectively. Our SmartHVAC app is compatible with Amazon Alexa and Google assistant. You can also control your DIY anywhere with your Apple or Android smart device with an Internet connection. Doing it yourself has never been easier with the new MRCOOL DIY E Star Series. This unit is shipped in two boxes.