I bought a Ryan home "used" the home has the original HVAC systems, the up stairs unit is a 2 ton unit, which is the bear minimum required for the 1500 square foot living area. they DID NOT FACTOR in the LARGE Windows, the Air handler and Duct work in the 100 plus degree attic. the result a system that can not keep up in the summer temper rises up to 5 degrees during the day. I have not been through a winter yet, but I expect it to be colder than the set point also RYAN Builders should be ashamed of them selves