Yes, MRCOOL DIY ductless mini splits are an excellent solution for heating and cooling a garage. This system is easy to install and efficient to run. To determine if 36,000 BTU is the right size for your garage, a good rule of thumb is that 36,000 BTU will usually cover up to about 1,800 sq. ft. However, the climate zone, number of windows and insulation quality can affect this number. For instance, a garage in a severely cold or hot climate zone, with 10 windows and poor insulation will need a higher BTU output than a garage in a temperate climate zone with two windows and quality insulation. For more information on sizing, please reference our Sizing Guide.