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Sizing Split AC Unit for Small Garage
How do I calculate the size of split AC unit for my small workshop/garage? It is ~390 sq ft so a small unit I think. 9,000 or 12,000 BTU likely. This area is an addition to the two car garage but it is fully insulated 2x4 wall adjoining old garage and the rest 2x6 wall construction with fiberglass batt in all the 10' high walls and blown in insulation in the attic to meet MN code in 2006. Exposed concrete floor which also has 2" foam board underneath between cement and soil. Garage door is also insulated. I have 110 and 220 subpanel for power available in the room and it has a double 30+30 amp 220 breaker that is never used since I sold my big table saw years ago.