with 4 mini split units, 3 12-15k btu units in bedrooms And 1 20k unit in living room. In cooler months run 2 of them for a few hours in evenings. In hotter months run at least 3 of them from 8-20 hours each. Home approx 1500sq ft. Temp set to 25 wherever I happen to be, 28 - 30C in other rooms occupied by natives