We currently have a 5 ton Carrier AC unit for the 2,200 sq ft first floor of our house in Oklahoma. I have always thought it was oversized as the humidity inside the house during the summer months is higher than it should be. A reputable HVAC company ran a load calc recently and determined that we should have a 3.5 ton unit. We are trying to weigh the benefits, cost and comfort, of replacing our existing unit with a smaller one.
I know that a 3.5 ton unit will have to run longer per cycle, but all things being equal, will the cost to run the smaller unit be about the same as it is for the 5 ton unit, which runs shorter cycles? I know the smaller unit should be able to create a more comfortable environment, but I'm wondering about the operating cost comparison of the two.