[tuccillo]

My garage doors face to the southwest and in the afternoon they became so hot you could not keep your hand on the aluminum. They were essentially a large infrared radiator. I did insulate them and the garage is cooler but I don't have typical before and after temperatures to be able to report by how much. What I have measured is that the garage now heats up to essentially the outside temperature. That may be the best that can be hoped for. I feel it was worth the drop in temperature.

Originally Posted by Roaddog53

If you choose not to put in door insulation that is your prerogative. I chose to since I have a refrigerator, Harley, and other equipment that is more heat sensitive and the more I can reduce the air inside, the less the refrigerator has to work. The 7-10..or more degrees cooler I felt was worth it. Obviously it won't get it LESS than the temp outside, but the closer I can get to it the better in MY perspective. I too can open the garage door and window when I am working in there to eventually equalize the temperatures. But when you open the door going out to the garage and it is 100+ somehow that has to have a detrimental impact on cooling. How much? I am not the expert, I did it for comfort and heat reduction, not pay backs, energy savings, period. However, since 1/4 of the house walls touch the garage AND the open garage attic of 600 sf is part of the rest of the attic, it makes sense the added heat may cost something more to cool the house. Otherwise, go wrap your house in 100+ heat like some days in the summertime and tell me your cooling bill is not higher than at 90 degrees. In the winter, when it is 25-30s outside, keeping the garage a bit warmer is also nice.