This magical white goo will take the temperature of a roof in AZ from 200+ degrees (summer) down to about ambient air temp or below. 

@Steve Kontos ; Truer words have never been spoken, I'm a fairly handy person when it comes to mechanical things (painting cars, welding panels, fabrication) but had never done construction work.

=(I have stayed in an airbnb before where I had to stay in the guest bedroom and it was a NIGHTMARE not having control over the AC temperature as I did not have access to it at all.

You can educate your tenants on this.Once you have it serviced you can see if there was something that you feel you should give the tenants a allowance for.Ultimately you can tell them you have no control on the temperature, their thermostat settings etc.

Root causes for high humidity: too much moisture getting into the air, not enough ventilation, not enough air movement, low air temperature. 

I use a smart thermostat to let me know when the temperatures and humidity are out of range and it uses ifttt to notify me.

At the same time Bay Area temperatures hit 120 degrees.

The local "hackerspace" (like learning how to weld and do carpentry and stuff) moved there and a lot of art studios and other hip things were all developing down there. 

Because when the "feels like" outside temperature is in the triple digits, there is only so much that can be done.Every once in awhile you'll run into a property insurance company that doesn't like window units. 

That's the temperature from my vantage point, anyway.