Air Conditioning a garage shop

[Douglas Robinson]

I am moving to NC and will be setting up a garage shop. It gets very HOT in the summer. There are two windows in the shop. I will have about 250 square feet with an 11 1/2 foot ceiling. Any recommendations how to air condition this space? Window unit? Portable unt? Size?

Thanks

[Lee Schierer]

A window unit would work, but unless the garage is insulated, including the door, it won't be a cheap date for A/C. Every time you open the outside door you will let the cold out and the hot humid air in.

Just don't try having the unit on a stand completely in the room. That won't work at all. You need to exhaust the hot air out side.

[Andy Fox]

Try a big fan or two in the windows to suck air out of your shop. Open a door/window on the other end to get cross-ventilation. Get another big fan to blow directly on you. The cross-ventilation helps a lot with fine dust too.

You'll still sweat some, but probably not as much as you would when your electric bill arrives if you use AC. :D Give the fans a try first, they're cheaper and simpler overall.

[Tim Solley]

Try a big fan or two in the windows to suck air out of your shop. Open a door/window on the other end to get cross-ventilation. Get another big fan to blow directly on you. The cross-ventilation helps a lot with fine dust too.

You'll still sweat some, but probably not as much as you would when your electric bill arrives if you use AC. :D Give the fans a try first, they're cheaper and simpler overall.
Douglas,

Expanding on this ventilation idea. My dad is a firefighter, and taught me a great trick when I was a kid. When firefighters are ventilating a structure, they'll sometimes place a fan five or so feet from the door, on the outside, blowing in. Open up a door on the other side of the garage. What this does is the column of air being moved by the fan sucks the surrounding air around the door in as well. That small fan can easily move twice as much air than if it were just placed in the door frame or in a window.

I too have a hot shop predicament. I live in central Texas and spend all summer long cooking and sweating out in my shop. I just live with it.

Tim

[John Harden]

How about one of those pedestal air conditioners that they sell at Costco or Sams Club? I see them all the time for about $400 or so and they have around 10,000 btu output. Would these work?

These are a better solution for me than a window unit as I don't have a window that opens. I can vent it outside using the supplied hose. My shop is in a 3.5 car garage, so it may not make it 70 degrees, but hopefully will take the edge off.

Anyone have experience with these?

Regards,

John

[Paul Muhlstadt]

If you use AC, make sure you protect your equipment. If you shut the AC off at night or when your not in there, the cool equipment surfaces will sweat. Sweat=water=rust!!!

[Mark Duksta]

Paul,

I have two portable units in my two car garage. They do OK until the garage door takes the full heat of the sun. It faces west. The door is insulated but the A/C units can't keep up. At night or during the first half of the day they do cool the shop down into the upper 70s. I have a 10,000 BTU and a 12,000 BTU.

The next time I cool the shop I'm going with a mini-split system.


Mark

[Tom Jones III]

I'm using an LG brand window unit, it is good and cheap. Get the biggest one you can and insulate as much as possible.

[Al Willits]

Try and go with a 220v unit if ya can, they're usually cheaper to operate and if this is in a shop, don't forget to clean the filter and coils.

Al

[Cody Colston]

I'm in East Texas and it gets very hot and very humid here in the summertime.

I placed a 18,000 btu heat/ac unit in the wall when I built my 600 sf shop. The shop is 2x4 stick framed, insulated and the 8 ft. garage type door (from HD) is insulated.

The A/C works very well as long as I keep the DC running. If I do much sawing/sanding at all without the DC, I have to wash out the coils on the A/C as they clog with dust and freeze.

[Ben Roman]

This is what I did !! Works really good in the Summertime over in the Austin Area ... Have to wait about 1 hour before I go in there but it keeps me just cool enough to work in there. :o

Ben

http://www.sawmillcreek.org/showthread.php?t=32986

[Dick Latshaw]

I have a 12,000 BTU window unit in my two car garage, about 400 sq ft. I also have lots of insulation in the ceiling (R13 or better) and foam panels on the garage door that face East. Keeps the temp at about 76 without a strain down here in hot and humid Florida. The ceiling insulation seems to be the most important.

[Matt Meiser]

I use a very large window unit (forget the size) in my 30x32x12 shop and it works great. Like others have said, the key is the insulation. My walls are R25 and the ceiling has about 18" of cellulose. Once I get my shop cool its easy to keep it there.

[Lopaka Garcia]

Ok a couple of thoughts here. What if the air you're blowing into the shop is really hot? Wouldn't you just be blowing hot air? I know there's the wind chill factor but it is still hot air. And second, unless you have a really good DC set-up, wouldn't the AC unit be acting as a DC unit? You might be cleaning out the AC filter more often than you'd like. It's a little warm too where I am, and unfortunately I can't take advantage of the trade winds here because then I'd have dust everywhere in the house, being that my shop is part of the house. :(

[Matt Moore]

I would suggest window units. Buy as big as you can. Also as everyone else said you may want to consider some insulation, at least in the attic.

My garage did not have a window to put a unit in, so I built a platform just benieth the ceiling then built a housing around the back of the unit and connected a 8" HVAC fitting to the top of the housing, put a hole in my ceiling and I vent the AC into the attic. Amazingly, it works.

[Alan Tolchinsky]

Matt, Yes, this is what I was thinking of doing with my new garage shop in North Carolina. Could you please elaborate. How did you make your housing in the back of the a/c unit? What happens to the condensate? How did you decide on the 8" piping size? This is the way for me to go since I have no windows either. Great ingenuity here Matt! Alan

[Matt Moore]

Matt, Yes, this is what I was thinking of doing with my new garage shop in North Carolina. Could you please elaborate. How did you make your housing in the back of the a/c unit? What happens to the condensate? How did you decide on the 8" piping size? This is the way for me to go since I have no windows either. Great ingenuity here Matt! Alan

I will try to take a picture tonight. At the moment the condisation drains out the back and down the wall. I did not think that part through enough and thought it would be easy to retrofit something since at the time I just wanted to get it up and working. I still don't think it will be too difficult though, it is just that it is heavy and up hight and moving it into position was not easy. Anyway, in retrospect I would just put a pan under it, cut a hole in it and have it train into a cup. I don't run mine for long periods of time so it does not build that much condensation. I do have the platform slanted a little so that it drains to the wall at this point.

8" piping - I just put the biggest I thought would fit and maybe let enough air out. It seems to be fine. My unit is fairly small, if you had a bigger unit, you could do two.

I made the housing with some thin sheet aluminum and aluminum tape.

[Jeffrey Makiel]

A window unit sounds like the simple solution. But keep in mind that window units often are the primary means of entry for a burgular...especially at ground level.
-Jeff

[Ed Blough]

My garage is 22 by 22 with 9 ft ceilings I put in a 10,000 btu window unit that works just fine. I was going to insulate the garage door but haven't done anything yet. Biggest problem I have is keeping the filter clean. I put an aux filter in front of the primary. I may build a filter box to go in front if I continue to have problems.
For security I built a solid frame that screws into the window.

[Scott Vigder]

A window unit turned on 24/7 will also help keep your humidity relatively the same. Make sure to watch out where you place the drain hose for your window unit...sounds like it will be taking a good amount of moisture out of your shop and could make a nice creek addition to the property.

[Alan Tolchinsky]

I will try to take a picture tonight. At the moment the condisation drains out the back and down the wall. I did not think that part through enough and thought it would be easy to retrofit something since at the time I just wanted to get it up and working. I still don't think it will be too difficult though, it is just that it is heavy and up hight and moving it into position was not easy. Anyway, in retrospect I would just put a pan under it, cut a hole in it and have it train into a cup. I don't run mine for long periods of time so it does not build that much condensation. I do have the platform slanted a little so that it drains to the wall at this point.

8" piping - I just put the biggest I thought would fit and maybe let enough air out. It seems to be fine. My unit is fairly small, if you had a bigger unit, you could do two.

I made the housing with some thin sheet aluminum and aluminum tape.

Thanks Matt, I'd really like to see a pic of your installation. I was thinking of using a plywood box to vent up through the ceiling into the attic. Maybe this would give more air volume for the exhaust. But I also like your idea of using two 8" ducts too. I've done a lot of drywall but man I hate to start cutting up my new garage sheet rock. :) Thanks again for your ideas. Alan

[Alan Tolchinsky]

A window unit turned on 24/7 will also help keep your humidity relatively the same. Make sure to watch out where you place the drain hose for your window unit...sounds like it will be taking a good amount of moisture out of your shop and could make a nice creek addition to the property.

Hey Scott, How'd you know I wanted a "nice creek addition" for my house? :) It gives you that nice country feeling. Alan

[Matt Moore]

Here is a picture of my setup.

[Alan Tolchinsky]

I'll steal your idea. Thanks for taking the time. Alan

[Tim Devery]

I run AC in the summer, but also run a dehumidifier all the time. This keeps the humidity low and the wood acculamited. My unit sits on a shelf, and the hose runs out the window.
Cheap insurance for expensive lumber

[Rich Torino]

Doug,
I live in South West Florida with hot, humid summers.. I instlled a 18k btu window unit (220 Volt) that does a great job. The only modification i did was to install an additional filter on the front grill to catch the saw dust..
Originally I was only using the the filter that was part of the unit. I learned after about a year that it was not adaquate enough for trapping the finer dust and I had to pull the unit, take it outside and actually hose the dust/dirt out of it.

[John Gregory]

Doug,
I live in South West Florida with hot, humid summers.. I instlled a 18k btu window unit (220 Volt) that does a great job. The only modification i did was to install an additional filter on the front grill to catch the saw dust..
Originally I was only using the the filter that was part of the unit. I learned after about a year that it was not adaquate enough for trapping the finer dust and I had to pull the unit, take it outside and actually hose the dust/dirt out of it.

What do you use for the additional filter? I have the same problem with my A/C. I keep it blown out with compressed air. And I got a washable pre filter. It works ok but I was wondering what others used as a pre filter.

John

[Douglas Robinson]

The information in this thread has been very helpful. One further question, does anyone have any tips/suggestions regarding insulating a garage door (aside from replacing one)? I do not recall how my new door is constructed, so I am just looking for general adice. (I am not adverse to duct tape);)

Doug

[Ted Jay]

The information in this thread has been very helpful. One further question, does anyone have any tips/suggestions regarding insulating a garage door (aside from replacing one)? I do not recall how my new door is constructed, so I am just looking for general adice. (I am not adverse to duct tape);)

Doug
I have an aluminum garage door. I went to HD and bought the 4X8 sheets of foam board, cut it in 2 foot strips and filled in the back side of the door cavity, and taped the seams. It has helped alot.
Ted

[Tom Hamilton]

Hey Doug:

I put a Sears 15,000 BTU, 110v window unit in my three car tandem garage. The shop occupies the third bay. I turn it on in the AM and set the temp to 80. When I go into the shop to work I turn the temp down and us a pedestal stand to blow on me.

I'm always comfortable.

The two bays with the overhead doors face west and are hotter than the shop in the afternoon, but I don't work in that part.

I try to control entry and egress through the overhead doors on shop days to conserve the "cool".

Tool rust has not been a problem when I shut it down at night. Houston summer humidity runs 80% plus, so it is a pretty good test.

I've been very pleased with the window A/C solution.

Good Luck, Tom, in humid Houston with a cool shop.

[Chuck Powell]

I use a window unit in my 20 x 24 detached shop. The key is to insulate the walls, ceiling and rollup doors.

I pull the unit every two years and clean the coils. I'm in eastern NC.

[Kevin Herber]

Here is what I did. I'm real happy with it.

http://www.sawmillcreek.org/showthread.php?t=20193

-- Kevin