It gets hot in Arizona! I recently added 715 sqft on to my house. The existing 900 sqft has a 2 1/2 Ton unit I bought 2 years ago. I need to install another unit(2 zones) and can't afford a contractor. Should I get a self contained package? Should I use electric heat in the roof-top mounted unit or should I use a heat pump? Any and all input would be greatly appreciated as I intend to purchase one on-line next wekk. 13 or 14 SEER? What size roof jack and main duct?. Thanks a lot Davey

Self contained package unit. You will not have to mess with refrigerant lines and pay someone to install the line set and charge the system.

Main duct size measurements will be contained in the install instructions.

Roof jack and slope will be determined by your roof. I believe they make adjustable ones.

A self contained/package heat pump system will cost more than a strait electric unit. Let your wallet be your guide.