Quick answer: Most garages need a mini split between 9,000 and 24,000 BTU. A one-car garage usually lands at 9,000 to 12,000 BTU, a two-car garage at 12,000 to 18,000 BTU, and a three-car garage at 18,000 to 24,000 BTU. In DFW, plan on the higher end of each range because of our heat, weak garage insulation, and west-facing doors. The only way to lock in the exact number is a load calculation done by a licensed pro.
