We are at 77° and 42% and it is real nice in here. I think ours is 3 ton but we have 2600 sq. ft. It's a old R22 system with a squirrel cage fan as big as your refrigerator. A hundred years ago it had the old swamp cooler system cooled by water from 4 cisterns around the house. Much of the old pipes and valves are still in place including the fan and ductwork.