Question about window A/C size

[cj87uq]

I have non conventional garage setup so I wanted to ask you guys what you think. My garage is approx 22.5' deep and 26' wide with 2 separate bays that are connected by a doorway in the rear. the bay on the left is approx 22.5x11' and the bay on the right is 22.5x15'. The way I have it setup is I do most of my general wrenching in the bigger bay(also where my Jeep stays parked) and do most of my fabrication in the smaller bay. I would like to install a window A/C to help keep it cool in the garage. I currently run a dual window fan as well as a small shop fan to keep it bearable in there. I have insulated walls and attic with about 8'10" ceilings. The door on the right bay is also a new door and is insulated. The smaller bay has an older door with no insulation. I know that it would be hard trying to insulate the whole garage with a giant wall going down the middle of it so I would like to just cool one side. The bigger bay is the bay with the window. I have installed a giant curtain in the doorway that separates the bays and even with just fans you can tell a noticeable difference in temperature between the rooms. My questions is how hard/easy do you think it would be to install a window A/C and keep just one bay at a nice temperature. I'm located in Portsmouth, Va where it gets into the high 90s with decent humidity during the summers. The side of the garage that I want to cool is approx 337Sq Ft. Do you think an 8,000 BTU unit would do fine or should I go big and get a 10,000? Thanks in advance for the help. Here are some pictures of my garage setup when I first moved in.





Smaller bay on the left




bigger bay on the right




Doorway that connects the two




This is whats been going on lately in the garage. You can also see the window here that the AC would go in




And the curtain that I just installed in the doorway today

 

[bandaidmd]

You could also add a window in the interior wall and use a box fan to circulate conditioned Air to both half's. I guess you went with one of the btu guide charts so I would just go a little oversize on what's recommended. Knocking that humidity down will be great for working condition.

Sent from my SM-N900V using Tapatalk

 

[Bruce Amacker]

Go as big as you can. I suggest a 220v unit so it will cool off the room as fast as possible, I put a 24,000btu unit in my garage and love it. Remember it has to cool off you and all of your tools, cars, and etc to work. And I'm much farther north than you are.......

 

[Bigbandguy]

I would go with at least a 12 for one bay and if you decide later to cool both sides another 12 would handle the other side and allow you to select which side or both. Rather than that curtain it would be easy to add a pre hung door and if space is an issue a pocket door between the two bays would maximize your space but cost more .
I agree that it would be better to go a bit larger and Bruce's suggestion above of a 24 would not be a bad idea. Some of the larger units also have a heater built in and those work very well for making the place bearable in Winter.

 

[LS6 Tommy]

An 8k Btu window unit won't do a thing in a 3375 square foot area. You're looking at 36k Btu easy... Way beyond a window unit.

Tommy

 

[Falcon67]

An 8k Btu window unit won't do a thing in a 3375 square foot area. You're looking at 36k Btu easy... Way beyond a window unit.

Tommy

LOL, he said "337", not 3375.

12K should do it. My large area is 24x28 and if I keep the big overhead door closed I can keep it nice with just a 10K Samsung. 8K will be too light IMHO, I had a 5K in the 12x24 section of the shop and it was pitiful I now use an 8K in there and it's perfect. Results vary by brand for sure.

If you can, I'd recommend putting it up in the wall and not the window. You'll miss having the window.

Window mount, converted to wall use.

 

[pattenp]

I have a 10K unit to cool 380 sqft and it does just fine. Don't size the unit too large because it will cycle on and off too much. It's better for the unit to be running for longer times to remove humidity.

 

[LS6 Tommy]

LOL, he said "337", not 3375.

Ho-lee chit! I guess I read the post waaay too fast...

Tommy

 

[MoonRise]

For one room of ~330 ft^2, in Virginia, with a 'basic' amount of wall insulation, some quick on-line AC sizing calculators provide an estimate that 8k Btu unit is going to be too little, a 10k unit -may- be OK, a 12k unit should be OK.

One fly in the ointment here (among several ) is the AC requirement 'adjustment' from the other bay. A piece of cloth in the doorway doesn't provide much actual insulation value between the two bays. As well as the non-insulated wall between the two bays.

As well as the large garage door(s), which are probably not insulated (if at all). And the effect of the large concrete garage floor slab, especially after several days of 90+F VA summer weather and then you want to go into the garage after the sun has been baking the garage all day and want to be able to do some 'work' without sweating instantly or waiting 4 hours for the AC unit to try and cool everything down a bit. Etc, etc.

https://www.alpinehomeair.com/hc/calculator/cooling_estimator.cfm

http://www.thisoldhouse.com/toh/calculator/0,,,00.html

http://www.northernac.com/newcalc.htm

YMMV.

 

[Falcon67]

One fly in the ointment here (among several ) is the AC requirement 'adjustment' from the other bay. A piece of cloth in the doorway doesn't provide much actual insulation value between the two bays. As well as the non-insulated wall between the two bays.

YMMV.

Well, I had this pocket door for years and it worked pretty well:

It's since been upgraded:

The wall it pockets into is not insulated and that hasn't really impacted heating/cooling of either space, at least not anything significant or obvious.

 

[nafterclifen]

I have a 12k window unit in my 20x22x9 with insulated walls, ceilings and doors. It cools it off very well. Can easily get it to 70. I agree that 10k would be the starting point.

 

[cj87uq]

Thanks for the inputs everyone. Sorry it took so long for me to reply. I ended up snagging a 10,000 BTU off of CL. There wasn't any 12Ks for a good price so I'll try out the 10K. I hope this work well.

 

[Falcon67]

Cool - seriously

 

[930dreamer]

Do you plan to cool it to 60 degrees? I need a unit for my 1200 sq ft shop still.

 

[cj87uq]

Do you plan to cool it to 60 degrees? I need a unit for my 1200 sq ft shop still.

No I thats just the setting it was at when I plugged it in.

 

[cj87uq]

First day in the garage using the AC. I set the AC at 68* and used a fan on the opposite side of the garage to keep the air circulating. Weather today was 79* with 40% humidity. I ended up turning it up to 72* because I was getting a little chilly, this was while I was doing cutting and welding in the garage. So far I'd say it works pretty awesome. Hopefully it doesn't struggle once the heat and humidity get worse.

Also the curtain does a great job of keeping the cool air in that one bay alone.

 

[Kapn]

I had a free window unit I used in my 2 car garage every now and then for the last few summers. Very noisy and on it's last legs, but after an hour or so the humidity was down and if I started it in the morning, the garage stayed cool all day. Would only take it from 92 down to 88, but it was blowing right on the bench and made it bearable. Would have loved to put in a mini-split and done everything right, but for those couple of days I needed it, it was good enough.

 

[slip knot]

79f with 40% humidity and you need AC???

Let us know how it works at 98f and 98% humidity.

 

[James-W]

I have a 10K unit to cool 380 sqft and it does just fine. Don't size the unit too large because it will cycle on and off too much. It's better for the unit to be running for longer times to remove humidity.

I agree totally. When the air-conditioner is running it is taking water out of the air which is just as important, if not more so, than cooling the air. It can't do that if it isn't running.

 

[54stude]

I have a good friend that has a 1,000 square foot well insulated garage in MN, 5k btu ac with digital temperature control. And a ceiling fan he lets run. He turns it on and runs it 24/7. Works great.

 

[sseddon641]

If it was me I would buy the biggest unit that would fit in the window. Reason being is I don't always know when I'm going to be in the garage so I don't turn heat or Ac on until I'm in there. It's not fun turning the Ac on and it takes 2 hours to drop the temp to where you want it. Yes the unit may cycle once down to temp but I typically just shut mine off once I'm comfortable. It may take half an hour to an hour for me to get so hot that I want Ac again so I turn it back on.

 

[zmaxmotorsports]

79f with 40% humidity and you need AC???

Let us know how it works at 98f and 98% humidity.

Welcome to june in nebraska!

 

[Falcon67]