I'm not sure the electric bill would be higher, as central heat & air is usually more energy consumptive than a window unit. 

I don't believe quality tenants would rent a property in Phoenix without air conditioning.

I am a UCLA graduate and have a background in film and acting but currently I'm a tech project manager for a startup.I also own a duplex in LA that I rent out and I Air BNB two properties in Greece.What I'm looking for:1.

I'm a retired Air Force veteran and I work full time as a maintenance supervisor for an apartment complex. 

I started changing the air filters for my condos’ ACs and I would take time to scan around then and anytime a repair was needed my handyman would give me the scoop then too.

If you are paying heat/air costs, it will reduce the cost and make you happy. 

I just furnished a house to rent out and the utilities went way up due to air conditioning costs, etc. 

Stationed here because of the Air Force, but will be moving on to somewhere else in about two years. 

@Jessica Jay-Maleski, since I'm sure air conditioning is a must in your area, I might consider upgrading the units to have ductless mini-split air conditioning systems.

Tenant erected a 12 x 12 outdoor extendable living accommodation shed in the backyard without any permission installed permanent tiles, ran wiring in the shed for lighting, fans, for electrical devices and also for air conditioning.