15,000 BTU Window Unit for 576sqft?

[Diabolic]

I have a 24'x24' garage that I want to get cool on these 100 degree Texas afternoons. My garage has no windows, but the studs are spaced 24" OC. Between the studs this gives me 22" to trim out and I have found a few 15,000 BTU window units that will fit. I have 8" of spray foam on the ceilings, 12', and 2" of rigid foam on the walls. My garage door is a double sided steel with insulation. Should a 15,000 BTU unit be enough to cool it off?

 

[glntom]

I have a 15000 btu unit in a 1000 sq. ft. shop in southwest arkansas , keeps it under 80 degrees, even on 100 degree days.

 

[carap]

I am cooling my 2,000 sq' metal building with a 28,500 btu window unit. It has 14' ceilings with 6" of fiberglass on the ceiling and walls. On the hottest days last summer (110 f) it would keep it at 80 f. I would think 15K btu would easily cool your shop.

 

[Diabolic]

I sweat quickly. I'd like to see 72 on a 100 degree day.

 

[Diabolic]

Should I mount it up high on the wall or low to the ground?

 

[pseudorealityx]

What are you doing in the garage? Anything that produces heat? Lots of lights? Need to open the garage door often? Multiple people?

Keep in mind that units are typically rated at 95 degree outside temperatures. At 100 outside, they'll lose ~5% of their capacity.

 

[Diabolic]

I'm installing a 2 post lift and plan to keep my 93 Lightning in there. I only get the weekends free to spin wrenches and it gets so hot in June-Oct that nothing gets done between 11am-7:00 pm. Just me in there listening to the radio and wrenching.

 

[pseudorealityx]

If it's 100 degrees outside, how hot is it inside?

 

[Diabolic]

It gets to about 82-85 degrees.

 

[Dustball]

A 10k BTU window unit was enough to keep my former 720 SF house at 72 degrees in the summer and that house had nowhere near as much/as good of insulation as you have now.

 

[1949 caddyman]

I have a 15,000 BTU window unit in a 23x20 insulated shop in 110* Arizona & works good.

 

[IONH]

The slab will hold heat. Do you plan on running the A/C all day every day or just while you're in there?

 

[jhelrey]

It will at least knock the edge off... which is sometimes all it takes.

 

[James-W]

I have a 24 X 36 garage and I heat it during the Winter. I was planning on putting in central air this Summer, but I decided to just try a window air-conditioner to see how it would work out. By all rights, to cool an area that size I should have a 16,000 btu unit or an 18,000 btu unit. But the garage is built from 2 X 6's so there is R-19 in the walls and there is R-30 in the ceiling. More as a test than anything else, I decided to buy an 8,000 btu unit and see what it would do to cool down the garage.

Well, the 8,000 btu window air-conditioner is not really capable of cooling down the garage to a temperature of 72 degrees. But it does take a lot of moisture out of the air and even on really hot days it does cool the garage down to where you can work out there without much trouble. Unless it is unbearably hot outside, the inside temperature will be in the mid to upper 70's. On super hot days it will hit 80 degrees inside but since the humidity is really low, it feels much cooler than that.

All things considered, even an 8,000 btu air-conditioner can make a pretty big difference in a well insulated area. But if I really want to keep the garage cool, I will need to buy a bigger unit.

 

[kenfath]

Should I mount it up high on the wall or low to the ground?

My suggestion is to mount it so that the bottom approx 5' to 5'6" above the floor. WHY? It won't ingest as much dirt as it would if mounted at floor level. Air circulation is better as the cold air falls to the floor. Some day the AC units will require removal for service or cleaning. This is a practical height to manhandle a heavy unit to or from. Its out of the way.

Locate the AC unit in the area where you will be spending the majority of your time. Take advantage of the cold discharge air by having it blowing where you are. You will feel more comfortable. The distant areas will take care of themselves.

 

[1949 caddyman]

Also have plenty of ceiling fans to move air around, this will make it feel cooler to you.

 

[Falcon67]

It'll work good - mount it up high. Get one with a remote - very handy. I have a 10K for my 672 sq/ft work area and if I set the timer to come on about 4PM it'll be low 80s in there when I get home about 5:30. I have a 6500 in the 12x24 tool room and it works OK with a fan to help. The 10K Samsung is a much better unit than the Frigidaire's they sell at Lowes/HD.

>If it's 100 degrees outside, how hot is it inside?

Summer - My west wall will be 135F outside and the inside wall will be around 90~95F, no air running.

 

[Diabolic]

I just installed a spare 10,000 BTU unit I had laying around to test it out. It droped the inside temp to 78 on a 97 degree day. It felt really nice in there with the fan running. I'm going to purchase a new 12,000 BTYU unit and call it a day. This 10,000 btu test unit is 10+ years old and really beat up. Probably only running 75% of what it should.