I was woundering which unit would be more efficient for cooling home in Tucson Az? I have a 1780 sq ft home, included is an addition of @ 280 sq ft that has no duct work for vents. Home is a made of brick with the exception of the addition, I also just had dual pane windows installed and home is well insulated. I was woundering if I were to use a 4 ton unit over a 5 ton unit (13 sear) what would be the average difference in my utility bill, as well as cooling of home and ware and tear on unit?
Thank you!

Call a pro in and have a manuel J done. No other way to give you correct answer other than a guess

- How big are the windows?
- How much wall space?
- How much sun do the house walls get?
- How high are the ceilings?

All these factors can dramatically effect the size needed.