I live in North Carolina and I use my garage as my workshop. The temperature in my garage reaches 95 quite often. I have a gas hot water heater, a refrigerator and a freezer in the garage and I know that this all contributes to the heat. I've tried insulating the hot water heater, adding a whole house fan in the ceiling that vents to the outside and a ceiling fan all with no results. My last hope is that I could add a window unit air conditioner (approx. 8,00 BTU) in my garage. The only problem is that I don't have a window in my garage. My question is if it would be feasible to make an opening that just fits the outline of the air conditioner and not actually add a window. Can you make a really good seal around the air conditioning unit this way? My garage is approximately 800 - 900 square feet.
Thanks for any help
Don

It is feasible. A few years ago I helped my neighbor install a unit in the side of his house where he had no window. Just framed it like I would have for installing a window. Built a plywood box and attached that inside the opening. Put some trim around it on the inside and J channeled around the outside then replaced the siding we took off. You could use a foam weather strip to seal it, but my neighbor just caulked his on the outside. He built a box to cover it in the winter time. Rain and such should be no more a concern than if it was put in a window.

Careful measurements (measure twice-cut once) and framing the opening as you would a window should work with no problem. This is done quite often. You probably want to keep the base on a slight slope (angle) so the water created by the unit, will drain outside. Seal it well and you should have no air lost to the outside.
I wouldn't hesitate to go with a 10,000 btu unit. Better to much then one that will be overworked and not do the best job.

Why put a hole in the garage when you don't need to?
There are portable AC units on the market...some have heaters built into them also.


http://www.homedepot.com/Appliances...ogId=10053

Put it on the north side of the garage if possible.

Put it up high.

Cold air drops.

Is there a ceiling?

Is the garage insulated?

If its 900 sq ft. You will need 18,000 btu......

The R.O.T.is 600 sq ft. per ton of refrigerant or 12,000 btu's 300 sq ft more or1/2 a ton of refrigerant or 6,000 btu =18,000 btus

The most important thing is that the garage must be insulated or cooling will not be effective.

These are all good suggestions, and made me start to think......
I would get a big enough unit so it would not be over worked. It would have a thermostat control switch ( remote controlled) that would also have the energy saving option. I would put it up high not only to better cool the place but, also keep the dust from collecting in the filter. I would run a pipe from the drain plug down the wall and away from the house..

OKAY, but you don't want it too big, or it will cool too quickly and won't run enough to keep the humidity down.

If its 900 sq ft. You will need 18,000 btu.

Scooter... So what your actually saying is it comes out to about 20  BTU's per 100 square feet

Posted By ron 45 on 09-09-2010 12:22 AM
Scooter... So what your actually saying is it comes out to about 20  BTU's per 100 square feet

Ron,
Need to 'double-check' your math..... that would be 20 BTU's per SQUARE FOOT..... or 2000 BTU's per 100 sq. ft.

Slug-Gunner.... It serves me right, I never did learn how to type. I've always been the two finger typer, recently trying to twach myself to use all the fingers. I honestly don't know how the two zeros got there. I meant to right ( type), " 20 BTU's per 1 square foot". When I came back from getting a cup of coffee and read what I had typed, I just changed the foot to feet ( plural ). Man, was I lost....

Posted By scooterdown on 09-10-2010 06:15 PM


200 BTU's per 100 sq ft.= 20 BTU's per sq ft.

Other things to consider......

Windows,shade, sun, N. S. E. W. exposure.air tight insulated, high or low ceiling

Open the over head door good-by cold air.

Just the human body temp 98.6 x 5 will effect cooling.

How many hours are you using the shop?

How long will you have to run the A/C to bring down the temp so you feel comfortable to work in 95° F.

I can see a 36" or 42" shop floor fan used as an exhaust at one of the garage doors creating a draft from another open source. This will help to exhaust dust and fumes.

If the water heater is gas...watch out when using flammable products for painting and solvent cleaning.

get a mini split system it costs more but most efficent ,i work in the hvac field.plus u have extra heat sources, go with a 2 ton system.it only requires a 3 inch hole to hook up.good luck rick