AC'd the garage. Do I insulate the walls?

[pieter3d]

I just put a 25k BTU wall unit in my attached 3-car garage (single level house). I insulated the doors with 1.5" styrofoam, and am planning to have 10" of cellulose blown in to the attic above the garage. I am wondering if I should insulate the garage walls as well? Right now they just have the 1" styrofoam backing for the stucco.

My concern is that if I do so, I will have to run the AC a lot after parking a cooling car in it since the car's heat can't escape then.

I live in Phoenix, so it gets pretty damn hot in the garage in the summer (120F easily). My goal is to be able to cool down the garage when ever I want to work on the car or some other garage project, not to keep the garage cool all the time (power bill!). I still want the car to be able to cool normally when I'm not in the garage.

 

[Joe Reed]

Leave the garage doors open until the car cools down a bit, then close the doors and turn on the AC...

 

[sneezer41]

Please don't insulate at all. I have lost a TON of money in the stock market lately and have taken refuge in local utility stocks, so please, leave the doors open, lights on and ac running, I really need the money.

May I recommend dark toast? Incandescent light bulbs? A dozen of those 2000 watt outside yard lights..................

 

[dave67fd]

Not to sound **** but your reasoning makes little sense especially in your situation. Insulate, Insulate, Insulate. Your 25k will run constantly and won't do much especially in Arizona. If it's 120 in there whats a hot car going to raise it to? 125. The cars surface temp will be just as bad. The tighter you make it the easier it will be to cool and stay that way.