A Mrcool DIY Series heat pump is the only ductless mini-split system on the market explicitly designed for amateur installation. You don't need special tools or training to install this high-efficiency heat pump. The line-sets pre-charged with R410A refrigerant, the quick hook-up electrical connections and the quality engineering mean just about anyone can install a Mrcool DIY in their home with no problem at all in only a few short hours. If you want great air comfort without paying an arm and a leg for installation, you want an easy-to-use Mrcool DIY Series ductless heat pump.