Has anyone tried a portable air conditioner in their shop?

[Kevin Herber]

Silas - I live in Austin and am in the process of putting together a portable unit that I am pretty excited about. It uses a Carrier 'Mini-split' system.
This is basically a one- room central system. I live in a condo so I cannot punch a hole in the wall to permanently set this up. I came up with a portable solution that uses the garage door without modification.

The system consists of two pieces: the air handler and a condenser.

The air handler is approximately 36 inches wide, 10 inches tall and 6 inches deep. It would normally be mounted in the room on a wall. The condenser is about the size of a large pullman suitcase. It would normally go on the outside of the structure. They are connected with tubing for the refrigerant, just like a regular central A/C system.

I built a framework that resembles an oversize hand truck. The upright is 6 feet tall and the base plate is 30 inches square.

The air handler will be attached to the top of the upright. The condenser is on the base plate near the front edge and away from the upright.. There is 12 inches of space between the upright and the back of the condenser.

Each corner of the base plate has a wheel which is on a hinge so I can lower the ¼ inch thick base plate to the ground when I place the unit into position.

When I want to use the system, I open the garage door, roll out the unit and position it so the garage door comes down between the two units creating a wall just like the unit was permanently set up in a building. Because the plate is only ¼ inch thick and rests on the ground the door’s weather stripping can still seal the bottom of the door.

The unit runs on 120v. I had a separate circuit put in so it is not disturbing nor is disturbed by other equipment.

When finished using the system I merely fold the wheels back under the plate, unplug it and roll it back into the garage.

If I were able to permanently mount the system it would require only a 4 inch diameter hole through the wall to connect everything.

At this time I have the frame built and the two units ready for mounting. I need to finish mounting the units, get the system charged and begin using it. I’ll post the results when complete.

This is pretty pricey. I got the system for $900. The frame cost $150 (I don’t weld). Misc things: wheels, paint, etc was another $50. The A/C guy is charging $200 to plumb, evacuate and charge the system. The new circuit was included in a full electrical change for my garage so I am not pricing it separately. Roughly $1400 to $1500 when complete.

The last step will be to create some sort of air filtration to keep sawdust from being sucked into and across the wet cooling elements. I have some ideas but have not designed anything yet.

Let me know if you have any questions. I’d be happy to share any info.

-- Kevin

[Silas Smith]

There are some great suggestions here, my main goal is to keep down cost to a minimum because hopefully this is our last summer here and I would hate to drop $1000 on something that would only add value to someone who plans on spending alot of time in the garage. I will be moving to Idaho, so I guess then I will be whinning about the cold. At least you can wear a coat for that. I think there is more to the idea of creating my own portable unit out of a window mount. Pics will follow if I go that route.

[Mike Cutler]

Silas. Ellen has the right idea.
I have a Penquino portable air conditioner, 10,000 btu's. It rolls around on wheels and uses a 4" dryer duct for the exhaust. Absolutlely fantastic!
It is expensive,@ $1000.00, but you can take it with you wherever you go. It gets hot in Idaho in the summer so you wouldn't have forfeited your investment, just take it with you when you leave. I'd trade every "window unit" I've ever had for these.
You could put a "cat" door on the garage door and exhaust out the cat door.

[Don Selke]

Hi Silas:

I have a 18 thousand BTU AC unit mounted thru the wall of the shop here in Chandler AZ. The temperatures here can hit 120 degrees from about 2PM till 9PM or later. I am in the shop at 6AM and out of the shop by 10AM If I were to run the AC unit each day all day, I would drive myself into the poor house with the electric bills. I also have to cool a 2300 sqft home as well. When the Monsoon season hits (humidity & heat) I completly close shop. That is the time of year that I decide to spend more time on the computer and my CAD program. I also soak in the pool or the shower. I know, it is a dry heat here in Arizona but 120 or 115 is still hot in all books. That is OK since I am retired and can spend October thru May in the shop with all the garage doors open and plenty of fresh air and sunshine. During the summer months, we do get a lot of particulate air days depending on how many fires are burning in southern California.
Good luck on your project.

[Cecil Arnold]

Silas, there is a place on 34th (I think) that has the condenser units like Kevin described for about $200. I don't know what the air handler and evaperator would cost but you should be able to pick one up used for a reasonable cost. I have an 11,000 btu unit in my 11X24 insulated and sheetrocked shop in the Clear Lake area and it is adiquite. It will hold the temps below 80 on the hottest days. There is, however, one problem with my window unit, and that is dust. The A/C will pull sawdust through the coils and the dust will adhere to them, thus losing efficency. I had an 8,000 btu unit that initally cooled okay and than just lost its umph. When I replaced it I added an additional filter over the really poor factory filter and that seems to be holding up much better. One other thing that would favor the split unit, IMHO, is that with a window type unit you can not remove the humidity from the shop, so it really takes some cooling to keep the heat down. With the split unit you can remove the humidity which adds to your comfort. If you are interested in the condenser PM me and I'll look up the address. It's a used appliance place where we bought a few things for a rent house.

[John Hart]

Silas, I can't help but wonder if your brick facade goes all the way to the top. My reason is, putting an air conditioner near the floor requires that the air conditioner works very hard to cool the whole shop down since the cold air is just going to lay on the floor and build upward slowly.

If you have any area up high where you can cut a hole, the cold air will fall through the warm air and cause natural air movement, which will cool the area more efficiently, and give an out-of-the-way location for your unit.

Depending on the height, you might need a remote control or a ladder though...hmm

[Silas Smith]

Unfortunately the brick goes all the way up so I really don't want to cut into it. My friend had a suggestion where I just roll up the garage door and build a false front in the opening. I know my neighbors would hate it though.

[Jim Becker]

Silas, remove the overhead door (so it doesn't block your lighting, and build a false front that still LOOKs like the garage door...that should satisfy your neighbors...and still leaves you the option of putting a surreptitious hinged door for entry and exit with materials...and more wall space for storage.

[Glen Blanchard]

Silas. Ellen has the right idea.
I have a Penquino portable air conditioner, 10,000 btu's. It rolls around on wheels and uses a 4" dryer duct for the exhaust.

Mike - How long is your exhaust hose? I have nbeen told that these need to be fairly short - around 4.5 feet.

[Mike Cutler]

Glen the exhaust hose for my penquino is approximately 22 feet. The whole run has a downward slope, which made it easier for me. The Penquino has a backpressure shutoff if you exceed the exhaust backpressure rating.
If you needed to go up and out a window it would be a little more difficult, and that is probably where the 4.5 ft. value comes from.
The biggest benefit for me is that a Penquino can be vented out of an Anderson Casement window very easily, and that it is portable. I tried to order an AC unit specifically made for casement style windows for 2 years and never could get one.
We don't have Texas style heat here in Ct, but July and August can have some 90+/90+ days, and the single 10,000btu Penquino can do my entire house.

[Tom Jones III]

Has anyone tried any AC solution without having insulation? I've got a 3 car garage with a large attic type area. The walls are hardiboard on the outside and nothing else. I would love a roll around AC unit or window unit just to relieve some of the heat but I'm not willing to finish the garage. Will a small unit help any?

[Ellen Benkin]

I recently replaced an old VERY NOISY window unit that still worked and the guy who did the work said he would take away the old one because he could sell it to someone for their garage. As long as you can vent it somehow it should work

[John Hart]

Has anyone tried any AC solution without having insulation?

This reminded me....At work, in the center of our production area, there is an office where the production guys hang out. They wanted that office space air conditioned and it was not insulated in any way. The maintenance people installed a window unit in the wall with the exhaust going into the production hallway.
The result you ask? -- The area surrounding the production office was about 120 degrees F and the inside was at a comfy 70 F. It ran all the time of course...But it worked

[Mark Duksta]

I have two in my garage shop. They do OK for most of the summer. They have a hard time in August in the late afternoon. My garage door faces West. The door is insulated but the sun still heats it up pretty well. I cut two vent holes in the wall to exhaust the moist air.

Mark (in hot Austin,TX)

[Carl Eyman]

About 30 years ago an office built in the factory area had to be air conditioned. A window unit wasn't practical but the maintenance guru found a neat little unit about the size of a 2 drawer file cabinet cooled with WATER. Thaty is, instead of discarging the heat into the air as a window unit does it discharges it into water. The water goes quietly into the sewer and every one is happy. This was in Wisconsin where tap water is about 52* year round. So it probably was more energy efficient than a window unit. But it sure worked well.