The fourplex that I am looking at does not have electrical conditioning system, but instead evaporative coolers on all 4 units.
I have not experience with this cooling system.
Is it possible to bring the temperature below 80F when the outside is above 110F?
Would houses with this kind of cooling system be able to attract high quality tenant?
"Swamp coolers" work well when the humidity is low, but during our storm season in late summer they will not cool enough. I don't believe quality tenants would rent a property in Phoenix without air conditioning. Most people who have an evap cooler also have AC. It is cheaper to run the evap with low humidity. I would suggest you talk with an HVAC tech for guidance.
The rule of thumb is it lowers it 15 degrees from what outside is when it is low humidity...so even if it is 100 with no hum that is still only 85 degrees...best be getting A/C.
The other main thing to consider is that evaporation coolers really increase humidity in the unit and without ventilation it can cause problems with mold. Also if tenants are not careful and there are both the cooler will kill the hvac systems' condenser. Best to just look at cost of closing the cooler and using small units.
Does anyone have any recommended brands?