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Air conditioning for an attached garage

Posted: Mon May 24, 2021 12:18 pm
by Soccerdad1995
I have a 3 car attached garage that I use as a workshop. It is not insulated, and has no AC. I use a number of fans to provide a breeze, but during the summer months it is still unbearable to work in that space. After an hour or so, I am drenched with sweat.

I'm looking for options to get this space cooled. Any suggestions are welcome.

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 12:22 pm
by ELB

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 12:26 pm
by Soccerdad1995
ELB wrote: Mon May 24, 2021 12:22 pm I would start here: https://texaschlforum.com/viewtopic.php?f=83&t=100465
Thanks. I read that whole thread. The problem is that I don't have a window, and also can't have a unit that extends out of the side of my exterior wall if I were to cut a hole in the brick - HOA restrictions.

I was going to post this question in the thread you referenced, but didn't want to derail that discussion.

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 12:28 pm
by ELB
Ah.

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 12:41 pm
by Syntyr
If you have a smaller hole somewhere, hopefully on the backside of your garage you could try a portable AC unit. You didn't say if your garage was attached or detached. My detached garage backs into my backyard so I can get away with stuff the HOA would not approve of.. i.e. Window ACs or holes in my garage.

Something like this.

https://www.lowes.com/pd/Hisense-Hisens ... 5000151929

It has a round hose on the back to exhaust the hot air. Obviously, with a 3 car garage, you are fighting a big heat load. Your problems will be insulation, leakage around garage doors. output and expense of the unit itself and if you are in a high humidity environment you will have to drain or empty the unit's moisture collection system.

I had a large one, about the size of four of these units from a server room that I decommissioned. It kept most of my garage cool while I was using it. The problem is the initial cost if I had purchased the unit was 8k and the exhaust tube was about 30 inches in diameter. So it worked okay for a while until I just gave up. Oh, and the electricity was ugly. Cost about 60 bucks a month to run it half a day. So in the long run I decided to give up. My problem is my garage has zero insulation.

Something like this version. The exhaust port is on the top and requires a very large hose to connect to the outside. Prices have come down but this one is still about 2000.

Good luck.

https//www.amazon.com/dp/B01AAAY1ZO?tag=aclabn ... th=1&psc=1

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 1:37 pm
by philip964
Attic above or more living space?

Open rafters or sheetrock ceiling?

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 2:01 pm
by RPBrown
I would recommend a ductless mini-split such as Mitsubishi, LG, or Daikin. The indoor unit will mount on the wall and the outdoor unit is only 12-18 inches deep. Width and height determined by capacity. These are very efficient units and work really well but do your homework on brands.

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 2:43 pm
by Soccerdad1995
philip964 wrote: Mon May 24, 2021 1:37 pm Attic above or more living space?

Open rafters or sheetrock ceiling?
There is attic space above 1/3 of the garage. The rest is covered by an upstairs bedroom.

There is a sheet rock ceiling in the entire garage (no open rafters).

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 2:46 pm
by Soccerdad1995
Syntyr wrote: Mon May 24, 2021 12:41 pm If you have a smaller hole somewhere, hopefully on the backside of your garage you could try a portable AC unit. You didn't say if your garage was attached or detached. My detached garage backs into my backyard so I can get away with stuff the HOA would not approve of.. i.e. Window ACs or holes in my garage.

Something like this.

https://www.lowes.com/pd/Hisense-Hisens ... 5000151929

It has a round hose on the back to exhaust the hot air. Obviously, with a 3 car garage, you are fighting a big heat load. Your problems will be insulation, leakage around garage doors. output and expense of the unit itself and if you are in a high humidity environment you will have to drain or empty the unit's moisture collection system.

I had a large one, about the size of four of these units from a server room that I decommissioned. It kept most of my garage cool while I was using it. The problem is the initial cost if I had purchased the unit was 8k and the exhaust tube was about 30 inches in diameter. So it worked okay for a while until I just gave up. Oh, and the electricity was ugly. Cost about 60 bucks a month to run it half a day. So in the long run I decided to give up. My problem is my garage has zero insulation.

Something like this version. The exhaust port is on the top and requires a very large hose to connect to the outside. Prices have come down but this one is still about 2000.

Good luck.

https//www.amazon.com/dp/B01AAAY1ZO?tag=aclabn ... th=1&psc=1
Thanks.

It's an attached garage. There is brick on the only exterior side wall. The front has about 2 feet of siding above the garage doors and that area is pretty well covered by the eve so I could probably cut a small vent hole there if needed.

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 2:47 pm
by Soccerdad1995
RPBrown wrote: Mon May 24, 2021 2:01 pm I would recommend a ductless mini-split such as Mitsubishi, LG, or Daikin. The indoor unit will mount on the wall and the outdoor unit is only 12-18 inches deep. Width and height determined by capacity. These are very efficient units and work really well but do your homework on brands.
Thanks.

Do you know the approximate cost to get something like this installed? I don't trust ,myself on a DIY install.

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 3:46 pm
by philip964
RPBrown wrote: Mon May 24, 2021 2:01 pm I would recommend a ductless mini-split such as Mitsubishi, LG, or Daikin. The indoor unit will mount on the wall and the outdoor unit is only 12-18 inches deep. Width and height determined by capacity. These are very efficient units and work really well but do your homework on brands.
I would agree. But get a price on a regular split system mounted in the attic area as well. The ductless systems should be cheaper, but sometimes they are not.

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 4:10 pm
by mrvmax
RPBrown wrote: Mon May 24, 2021 2:01 pm I would recommend a ductless mini-split such as Mitsubishi, LG, or Daikin. The indoor unit will mount on the wall and the outdoor unit is only 12-18 inches deep. Width and height determined by capacity. These are very efficient units and work really well but do your homework on brands.
This, I can tell you that portable A/C's will not cool down a three car garage in South Texas. I have been using portable A/C's for the last 10 years for an 8x8 office in my garage and it can barely get the temp down to 78 in the summer for only 64 square feet. I have gone through at least 5 in the last 10 years so brand makes no difference. Split system is what you need.

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 4:22 pm
by 03Lightningrocks
RPBrown wrote: Mon May 24, 2021 2:01 pm I would recommend a ductless mini-split such as Mitsubishi, LG, or Daikin. The indoor unit will mount on the wall and the outdoor unit is only 12-18 inches deep. Width and height determined by capacity. These are very efficient units and work really well but do your homework on brands.
:iagree:

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 7:42 pm
by uthornsfan
Look up Mr Cool DIY mini splits.

You can order them on Amazon.

Re: Air conditioning for an attached garage

Posted: Mon May 24, 2021 8:23 pm
by srothstein
I think I would also consider the A/C unit that Syntyr recommended. I would put a turbine type exhaust on the roof and then route the exhaust hose to the roof outside of the bedroom area.

An alternative that might be too expensive in the long run might be to find the duct that provides A/C to the bedroom and install a section that blows into the garage. It would probably be the cheapest (if it can be done) construction wise but the electricity cost on the main A/C unit might be too high. Might even need to get a larger home A/C for that to work.