For those interested in generators here is a data point or two from "real world" experience.
I spent most of today at our Montana in its storage area doing various upgrades. Most of the time was spent on upgrading the water pump.
Being a hot day, I took my Honda EU3000is generator along so I could run the A/C.it was hot enough that the A/C ran 100% all day long. I don't know if this unit doesn't have very good insulation or what the deal is. I checked the temperature of the air coming out of the vents and it is maintaining a 25 degree drop which is very good.
We have a 15000BTU A/C. It ran for 9 hours on the one tank of gas. It wouldn't have run much longer as the tank was getting pretty well empty by that time. The only times the A/C was shut off was when I turned it off so I could use a power tool I had with me.
BTW: I was able to leave the generator on its "econo" mode where it slows down if it can. It was still able to start the A/C even when idled down.
This tells me that I will be able to start up the A/C with the generator and get a good nights sleep before the genny dies.
Without the sun beating down on the rig, it may go longer than 9 hours...
Eric