Window air conditioner for garage (24x32x12)

[scoob8000]

I've been wanting to cool my garage for a few years. I have NG for heat.

Saw some window AC units pop up on sale at Sams. Picked up the 12k BTU unit and went to put it in, but I cheaped out on my windows and it won't fit. I need about another inch of height.

I know 12k is even a little undersized by what the box says. Would it be worth grabbing a 8k BTU unit to at least cool it a bit?

Garage is a pole building, vinyl siding, house wrap, R13, OSB walls inside. Somewhere around R13-20 in the ceiling (blown in) over OSB. 3 single pane windows, insulated steel garage and man door. It usually stays fairly cool. Today was around 90 outside and it was 77 in the garage.

Or do I just wait and get a proper sized minisplit some other day.

[edit] I don't plan on running the AC 24/7. Just turn it on a few hours before I plan on going out to work on something.

 

[Tracs]

This is just my opinion but I sized my hvac equipment correctly. I have a 18k btu mini split in my 24x30x10 garage for summer air conditioning. I have a 6kw electric boiler for the radiant winter heat.

I set the thermostat 4 years ago and haven't touched it since. I read a lot of people on here want a heater or air conditioner and say they will turn it up or down when going to the garage. Equipment is most efficient when on at a set point all the time. The thermal mass of the garage and contents helps keep it cool/warm.

Some people spend more or less time than others in their garage and don't want to heat/cool when they are not in there. There are even times in the winter I haven't went in the garage in a week or two, but I still keep the heat/air set.

 

[Jazz1]

My garage generally stays cool if doors closed however eventually I did put a 10k window AC unit in that made a significant difference.

 

[scoob8000]

This is just my opinion but I sized my hvac equipment correctly. I have a 18k btu mini split in my 24x30x10 garage for summer air conditioning. I have a 6kw electric boiler for the radiant winter heat.

I set the thermostat 4 years ago and haven't touched it since. I read a lot of people on here want a heater or air conditioner and say they will turn it up or down when going to the garage. Equipment is most efficient when on at a set point all the time. The thermal mass of the garage and contents helps keep it cool/warm.

Some people spend more or less time than others in their garage and don't want to heat/cool when they are not in there. There are even times in the winter I haven't went in the garage in a week or two, but I still keep the heat/air set.

I get the whole heat mass thing. Goes back to, is it really worthwhile to turn up your house AC during the day when nobody is home type thing. But in reality I'm in the garage maybe once a week, sometimes I won't spend but an hour in it all month. I don't think it would make sense to keep it cool that whole time for me. But other times if I know I'm going to spend a few hours in there one day, I can crank it down before hand and at least take some of the edge off.

My garage generally stays cool if doors closed however eventually I did put a 10k window AC unit in that made a significant difference.

I just did some quick looking, it looks like the 10k's have the same size reqirements as the 12k I need to return. Did yours make a significant difference enough that it would be worth trying an 8k? I can get an 8k, smart unit for $199. I've wasted more on dumber things.

 

[rjacobs]

I bought a "portable" Toshiba 14k BTU unit that has a setup that goes in a window. It does air in/air out of the window setup vs. most that just exhaust the hot and then pull makeup air from all the cracks and crevices...

Toshiba 12,000 BTU Portable Air Conditioner Cools 550 Sq. Ft. with Heater, Inverter and Wi-Fi in White RAC-PT1411HWRU - The Home Depot

Bring the best of cooling technology to your home with this Toshiba Portable Air Conditioner with Dehumidifier Function and Remote Control in White.

www.homedepot.com

Works ok and my garage is about the same size as yours.

If I am going to go out there to work, I will go out early in the morning while the garage is cool from the night before and turn it on. If I turn it on when the garage is 95 already, it doesnt do much to cool it off, but does pull the humidity out. BUT to be fair, this unit at 14k BTU isnt large enough for the space. I think I calculated I needed at least 18k BTU or maybe 20k BTU...but I wasnt ready to spend close to 2k on a mini split.

 

[Bert_]

I bet an 8,000 window unit will cool the same space as a 14,000 portable, just because of all the inefficiency of a portable.

8,000 would probably do a halfway decent job if you leave it on. It would help a lot if you have high humidity.

 

[rjacobs]

I bet an 8,000 window unit will cool the same space as a 14,000 portable, just because of all the inefficiency of a portable.

This portable I got is supposed to be way closer to a full window unit than the past ones since it pulls air in from outside and then exhausts the hot air. They call it dual hose or something like that. MOST of the portable's only exhaust the hot air and thats what leads to their inefficiency.

I couldnt run a window unit because the windows in my garage are on the front of the house and we are in a pretty high dollar neighborhood.

 

[Jazz1]

I can confirm, Toyota was indeed using Noxudol 300s on Tacoma frames if they weren't replacing them. As per their documentation...

1. The temperature of the frame affects the drying
time.
2. Please ask the customer to avoid touching the
external surfaces of the frame as the surface may
remain tacky to the touch for a period of time.
3. Advise the customer not to wash their vehicle’s
under carriage for approx. 72 hours after
pickup. This will provide ample time for the
CRC to cure.
4. The customer may also notice a petroleum product
based odor for a few days. The customer may wish
to park the vehicle outside during this time.
5. Inform the customer that a hang tag for post CRC
application care will be on the rear-view mirror for
their reference.

I get the whole heat mass thing. Goes back to, is it really worthwhile to turn up your house AC during the day when nobody is home type thing. But in reality I'm in the garage maybe once a week, sometimes I won't spend but an hour in it all month. I don't think it would make sense to keep it cool that whole time for me. But other times if I know I'm going to spend a few hours in there one day, I can crank it down before hand and at least take some of the edge off.


I just did some quick looking, it looks like the 10k's have the same size reqirements as the 12k I need to return. Did yours make a significant difference enough that it would be worth trying an 8k? I can get an 8k, smart unit for $199. I've wasted more on dumber things.

I would go with 10K as I’m in area where AC Is not a every day use due to climate…Maybe a couple weeks each summer

 

[scoob8000]

I would go with 10K as I’m in area where AC Is not a every day use due to climate…Maybe a couple weeks each summer

I picked up the 8k. All the 10's I looked at have the same case size as the 12's. Just a touch too tall for my windows.

I can always pick up a small 5k for another window down the road too I suppose.

Good point too is it'll help the humidity.

 

[metlmunchr]

My detached garage is 24x48, divided into 2 sections by a wall. The part I work in is 24x30 with 8ft ceiling. Concrete block with stucco exterior, no wall insulation and R13 batts overhead. Two 9x7 wood overhead doors with 1" rigid foam insulation added.

Prior to installing a mini split, I had an old 5000 btu window unit that I installed in the 24x30. I figured it would at least help a bit with humidity, and since I already had it, why not try it. That thing could run for an hour on a day when the temperature was pushing 90 and the garage was totally comfortable. Condensate pouring out on the outside and the temp steadily coming down.

I'm in the mountains of western NC at about 2500 ft elevation, so my summer conditions are likely not much different from yours. I think you'll be pleasantly surprised at how well that 8000 btu unit will work out for you.

 

[Syberia]

I bet an 8,000 window unit will cool the same space as a 14,000 portable, just because of all the inefficiency of a portable.

I tried a "14k" portable in my home office when I first moved here. Didn't cool worth a damn, even being one of the two-hose models, and sucked electricity. Replaced with an 8k window unit mounted through the wall, which performs better. Swore off portables after that, and when I was returning it to Home Depot, there were at least three other people returning portable A/Cs at the same time. The guy in front of me had the same complaint - didn't cool.

For OP, if this is going to be for occasional use, I'd oversize the unit. If you don't have a window big enough, you can mount it through the wall. The last thing you want is to have to remember to turn it on ahead of time and wait hours for the space to cool down before you go out there and work.

 

[scoob8000]

So just an early update. Got it in and running around dinner time last night. It was 78 in the garage and I cranked it down to 68. I'm not sure how much it ran thru the night to drop the temp, but it was 69 in the garage this morning and it wasn't running.

I left it set there thru the day to see what happens with the heat of the day. Only going up to 85 or so here.

It's definetly pulling a ton of humidity out. After an hour of running last night, it was producing a lot of condensate.

Going to wait for a hotter day, let the garage get hot and see how long it takes to knock the edge off and be bearable.

 

[pbon]

I would just run it full time. That way you get the most out if an undersize AC.

 

[dmcintosh]

It seems a bit small to me from what I found when I was looking for cooling my 24x30x10 pole barn, I ended up mounting my AC directly through the wall, in stead of putting it in a window. If I remember I think my estimates pointed me toward an 18k BTU unit.

 

[ckanderson]

Are your garage doors insulated?

 

[scoob8000]

Just wanted to come back and post some thoughts/updates.

The 8k stuggles but seems to serve me fine for my intended purposes. If I turn it down the night before, it will keep it around 70 on a 85-90 degree day. I'm graphing my power usage with a smart plug so I can see when it's cycling. As the afternoon comes you can see it's cycles getting longer and longer. I also have a 24" drum fan that I have right next to it helping to circulate the cool air around the garage.

One day I'll drop some cash on a proper mini split. Until then, this is good enough. Plus only $200.

 

[Bert_]

If it will maintain 70* on a hot day, I'd say that's very good. Not struggling at all unless the temperature starts creeping up.

 

[Jakemedic]

18,000 btu diy mini split in my 24x32x10 post frame workshop. Does very well. Even before turning it on, it was only 76 in the shop and 90 degrees outside. I did spend some dollars with insulation and the best insulated garage door I could find. Stay coo, it’s brutal out there!