For What It's Worth
It isn't a working garage in the Texas Summer until it can be cooled off.
I can recommend the method
outlined below for boxing in an AC unit. When the tornado hit and
tool the garage away, the AC unit and the framed in box around it stayed and was
still in 1 piece. When the house was rebuilt, I had an opening put in the garage
during the rebuild.
Working in your garage in the Texas summer is an endurance test. How long can you endure an oven. An garage without insulation can get to 140F in Texas. Add high humidity and you are done in about an hour. I wanted to work longer than an hour a week.
The first step was to insulate the garage. Did that during a Thanksgiving break. Taking off the sheet rock and adding insulation helps a lot. Used the fiberglass rolls, about 3x the insulation over the blow in stuff. Then adding R40 worth of fiberglass in the ceiling makes a huge difference. Its quite comfy now even in the summer, but for "working" conditions still not quite cool enough and there is still the Texas humidity.
The last part I needed was some AC. My garage didn't have any windows, but a window AC unit was just about right for the size of the garage and wiring available. An opening had to be framed into the garage wall. Be ready for surprises anytime you get into a wall. My wall was pretty good, except for the one area that was a 19" gap, not 16" and had 2 studs together. Just right where I wanted to put the AC unit. I thought I better not try to cut the 2 studs that were together. Were they a load bearing special or was it needed for the spacing of the siding planks? I don't know which it was, but I left it alone. The double studs ended up working fine for anchoring the AC box on the one side.
After some remembering of carpentry skills, looking up window framing and measuring 2-3 times per cut I ended up with the following. I used 2x6s to make the box around the AC unit. 2x6s make it like a window frame and extends beyond the outer siding. Some calk, paint and a new piece of sheet rock and you are ready to go. My brother was a carpenter. The best things my brother taught me were to measure twice, and how to fix it if you mess up. Not too clear in the picture, but where I cut the wall stud, is a 1/2" home made shim to account for where I cut the stud too much. Drill through the header, shim and into the stud in 2 places and use 3 1/2" screws. It is not coming apart. In fact when I was done this section of wall ended up strong and very rigid. A good anchor for the AC unit
Picture inside the garage, before sheet-rock goes up.
Will it pull it down to 72 degrees? Most days, and high 70s is what this 10,000 BTU unit should handle in my garage in 100 degree weather. Mid to high 70s are nice working temps. And if you still need to cool down at times, a nice blast of cold air is available.
Happy Motoring, V Hubbard July 2012