I need help cooling my garage

August 13, 2007 8:14 AM

I'm in Texas and it's really damn hot. I have a workshop in my garage and I need to Get Stuff Done, I need help.

It's been a mild summer in austin up until now, and even so, it's very hot to work in the garage. I usually have the door open with 2 good-sized fans blowing, and I still usually lose a few pounds sweating.

But man, starting this week, it's been in the low hundreds and I can't even contemplate going to the garage to work.

Under normal circumstances sweating is a huge problem. I sweat all over wood, machinery, and into my eyes, which combines with sawdust to blind me.

I have an idea that might be crazy and I need someone to stop me if it is. I want to use a small window AC unit in the garage. I know that most of these need to circulate air to the outside to work. I was thinking about making a fake "window" to put the unit into, with ducting to vent it outside, either through the eaves or maybe I'd even cut a vent in the garage door (detachable of course)

My goal here is not to air condition the outdoors, just to bring the temp in the garage to below 90. This would necessitate closing the garage door which is OK for most things (I only need it open if I'm doing a lot of work on one side of the workbench, or if I'm cutting full sheets of plywood)

Anyone done anything like this? Any alternate solutions you can think of aside from this?

posted by RustyBrooks to home & garden (20 comments total)

you will need some way of forcing fresh outside air into your fake "window" and pumping the hot air outside. The external fins on a window unit air conditioner are totally passive: they simply radiate heat. So you need an active way to force that heat out of your fake window and to the great outdoors. Otherwise, you're just going to heat up the interior of the fake window and drastically reduce the efficiency of the unit.
I think you could do this with 3 inch dryer vent and some fans mounted inside the openings of the ducts.
posted by cosmicbandito at 8:38 AM on August 13, 2007

I don't see a problem with installing a window unit, as long as it backs up to the outdoors. There are also "mobile" AC units, that are freestanding and use a long hose to vent to the outside.

You might also consider a misting fan, which is basically a fan and a water spritzer.
posted by adamrice at 8:39 AM on August 13, 2007

this page has a few links to some "homebrew" air conditioning (on the cheap).
posted by kajj at 8:42 AM on August 13, 2007

I actually thought that window A/C units sucked air in through the vents - is all the blowing action of the unit just recycling air in the room? At any rate, yeah, I think I see what you mean, I could put a fan at the outside-end of the duct.

You might also consider a misting fan, which is basically a fan and a water spritzer.

This might be a bad idea with all the cast iron and wood in the place...
posted by RustyBrooks at 8:43 AM on August 13, 2007

I survived one North Carolina summer working outdoors by repeatedly soaking down a headband and most of my clothes with cold water. For about 45 minutes after the dripping stopped but before the water itself got pretty warm, things were tolerable. Might help a bit until you get the AC set up.
posted by salvia at 8:47 AM on August 13, 2007

Get a portable AC unit - they come with all the ducts and such already. And yes, the air in the room stays in the room and the outside air is only used to cool the hot part of the AC unit. There's never any inside-outside air mixing in a residential AC unit. You will probably have to clean the air filter a lot of there's a lot of fine wood dust.

Here's one at Home Depot.
posted by GuyZero at 8:54 AM on August 13, 2007

Actually, after reading the reviews, don't buy that exact unit. There are plenty of other models though.
posted by GuyZero at 8:55 AM on August 13, 2007

How about making a barrier, slightly taller than the window unit (I'm envisioning 2x4 framing covered in foam insulation panels) and then shutting the garage door on top of it? You could even make it in 3 or 4 panels so it would be easy to set aside when you wanted to close the door all the way.

Essentially this would be a way to install the AC, temporarily, as if the garage door were a very long window.

I live in Austin and have the same garage issue, so I've been thinking about this. I have yet to act though, so please update what you end up doing and how it works!
posted by dirtdirt at 8:59 AM on August 13, 2007

dirtdirt, that's a pretty good idea, actually. I don't know if my garage door opener will permit that or if it's go all nutty because it's not being allowed to close all the way. I wish my garage just had a freaking window.
posted by RustyBrooks at 9:04 AM on August 13, 2007

Have you read about the badly named Mr. Slim from Mitsubishi Electric? Promotional material says you don't need ductwork or window space. I've seen the cheesy commercials but, darn it, the unit looks kinda cool (no pun intended). See www.mrslim.com. Maybe it'll help you, maybe not; my intentions are good, fellow Texan.
posted by Smalltown Girl at 10:08 AM on August 13, 2007

"Mr Slim" is a typical ductless residential AC unit. A coolant pipe runs into the cooling unit inside, with a typical AC compressor outside. They cost the same, or more, than a normal residential central AC unit. They're typically only useful when there's no existing air ducts in the place you want to cool.

Most of these units are too large for single-room use. "Mr Slim" starts at 9,500 BTU, which is actually not too big for a single room, but you can get portable units that are smaller and a lot cheaper ($300 vs $1500).

Someday I will have to install AC in my hundred year-old house, so I have been looking at AC units a lot...
posted by GuyZero at 10:32 AM on August 13, 2007

You could try what roofers often do under those conditions. They work from mid-night to 8 AM.
posted by JackFlash at 10:46 AM on August 13, 2007

I have a 2yo son, so working at night is mostly out of the questions (table saws, air compressors, planers, jointers, etc, are loud)
posted by RustyBrooks at 11:41 AM on August 13, 2007

Disconnect the garage door opener if you're worried about it (It's just the red pull cord). Then open the garage door by hand to the desired location, block, and cover as suggested. That's probably the easiest solution. I would put the ac up on a few blocks so it's not sitting direct on the floor, allow a bit of airflow around the bottom of the unit.
posted by defcom1 at 11:51 AM on August 13, 2007

A roof mister system can knock a tremendous amount of heat off the roof of a building. Even a timed sprinkler that shoots water over the roof hourly might be a significant help. Heat that doesn't build up on your roof, won't have to be taken out by an air conditioner. And evaporatively cooling a roof is a lot cheaper in terms of utility cost than air conditioning, for the same removed heat load.
posted by paulsc at 11:56 AM on August 13, 2007

Wouldn't a simple attic fan in the roof help?
posted by Slarty Bartfast at 1:46 PM on August 13, 2007

You might try a swamp cooler to see if it helps, if the humidity wouldn't be too much.
posted by mrbill at 2:49 PM on August 13, 2007

Make Magazine had a few links today to homebrewed air cooling systems.
posted by judith at 3:33 PM on August 13, 2007

No a swamp cooler definitely wouldn't work in Texas. The work by adding humidity to the air to cool it down with the above 80% humidity already it simply wouldn't function or at least very little.
posted by DJWeezy at 7:01 PM on August 13, 2007

I looked into something called a welders vest a couple of years ago as a way of keeping cool while working in the heat. It's basically a vest with pockets you keep ice packs in. If someone you know is handy with a sewing machine you can probably create your own from a light vest. I've had very good success soaking one of those special wicking shirts that dry quickly and wearing it while I work. They don't hang off you like a normal wet shirt and it cools you off as the water evaporates. Just keep a bucket of ice water around to resaturate it when it dries. That combined with the headband idea might be a cheap fix.
posted by any major dude at 5:42 PM on July 3, 2008