I put in a Trane air conditioning system in my last house which was about 3000 sq. ft. The cooling capacity was wonderful, and very, very inexpensive to run. We put it in the attic as cold air naturally falls. We ran ductwork all of the way to the first floor and the system operated well. One problem happened in the first year though and I think it was the pump that failed. Fortunately we were still under warranty but the installer recommended getting a maintenance contract since this pump was used with all Tranes and was known to have problems. This was 7 years ago so the problem may be fixed by now. The outside unit seemed huge to me (about 4 ft tall) but I was very happy we went with Trane.