Sizing Your System - Ductless Heating and Cooling

How do I size a ductless mini split?
For cooling only use a factor of 20 Btu's per square foot for a well insulated home, 25 Btu's per square foot for homes of average insulation, and 30-35 btu's per square foot for poorly insulated homes. When considering a heat pump, refer to our system size selector link in the top navigation bar on each page of our site.
Where can I get more detail and specs for the equipment I am interested in?