Portable AC unit for shop?

[GaryA]

Frankly for the time I spend in the garage I'd think twice (and again) before I spend the real big buck on AC. (I do have a fan).

Funny story...

I have been thinking about buying one from HD to see if it works. The problem I think I'm having with these is that I know they're not designed to run all of the time as you mentioned. I'd say that I normally go in my shop at night (and ocassionally during the day for an hour or so. I was thinking that it might not be a good thing to shut it down and basically have radical temperature and humidity (could control with a de-humidifier I guess) swings...as opposed to having an efficient unit that could stay at a moderate setting on the temp, control the humidity, and when I go in the shop, I could crank it up a few degrees to chill it down a bit more if desired. Maybe I'm overthinking the importance of that (I am guilty of that from time to time )???

[radhak]

If you are using it just an hour here and a couple there, it would be a bigger waste keeping it running the rest of the time.

I am no engineer, but these portables are small machines and the start/stop should not be that big a deal as such.

I assume you do not have a fan in there, that's why you want this there? I have a ceiling fan and have no plans of getting any AC into the garage, portable or otherwise, and this will be my 3rd summer in there. I am ok with the occasional extra-humid day, and when it becomes unbearable, I just drop everything to go in for a cold one and the TV remote .

[ssmith1627]

Don't forget about air quality in there. I put in an old window unit in my garage for the same purpose and it really did quite well for something that came out of an old apartment and hadn't been used in 15 years. But to close in the space where you're making all this dust, insulate it, etc....it can lead to a lot of trouble as far as really trapping in bad air.

Do you have a DC to collect most of the dust at the machines as you create it ? Any other type of filter system to keep the air quality up ?

I used that window unit for a brief period last year but now I totally rely on a wide open garage door and two other doors open to the outside. I'm in the shade obviously and I let as much air move through as possible to hopefully serve both purposes. As was said above, when I get too hot and sweaty, I just go back inside to cool off for a while.

Just my opinion after a lot of conversations on this board and things I've read elsewhere. Air quality # 1, comfort # 2.

Steve

[GaryA]

Do you have a DC to collect most of the dust at the machines as you create it ? Any other type of filter system to keep the air quality up ?

Steve

I agree...Yep...Delta 50-760 1.5HP DC and a JDS 750-ER ceiling mounted air filtration unit....If I'm working with MDF, I'll either throw open the garage door and/or wear a mask/respirator...not going to mess around with the lungs...

[ssmith1627]

I agree with that. Just not worth it. I don't know if some of those sites over-inflate the importance of not breathing this stuff. But those factoids about the hobbyist getting as much exposure in a weekend as a professional woodworker gets in a year really make you stop and think. I thank the people at this site for opening my eyes to it before I got any further along in the hobby.

Steve

[Cheeky]

Man, it's getting hot down here....

So, I actually ended up finding this online...the Mitsubishi mini-split "Mr Slim" model for $915 + shipping for a 9500btu unit (I have a 11x20 shop) http://www.acsuperstore.com/Merchant...i_Cooling_Only

Guessing I'd have to have someone install it. Also - anyone out there know if i'd be better off going to the $1200 version which is 15000btu and 16 SEER - I know i dont need all of those BTUs, but would it run much more efficiently? Anyone else have any feedback on this type of unit vs. portable AC?

that's a great price. Mr Slim's are incredible. quiet, powerful and efficient. i had my 2800 sqft house done with 6 units for about 14K.

btw, that price is great.

[Red2000SS]

Just moved into new house and finally have a dedicated shop I dont have to share with cars - a 1 car 11x21 garage. I know it's hard for many of you to fathom right now and cold just thinking about it, but here in Florida, the heat is starting to set in. Anybody have recommedations for a portable AC unit? I cant use a window mount version because of deed restrictions...I've seen the small portable units that have a 4" duct - which I guess I can port through the block wall. Anybody have one of these or have any recommendations around what to go with? What about dehumidifier - necessary?

Thanks

I was sort of in the same boat - I have a 3 car shop, i mean garage... that I wanted to cool. Homeowner's Assoc. won't allow window units. I looked into getting a conventional AC, but was quoted $3-5K

I didn't want to spend a fortune but did want to be able to work comfortably in my garage. Here are some things I have tried / found out that may help you or others.

My garage is about 500 sq ft (18x28). My garage doors are insulated, and the garage tucks into the house so that 2/3 of the back wall and ceiling as well as the left wall are surrounded by air conditioned space - this helps a lot.

I first tried a dehumidifier since I found one on sale at Home Depot, thinking if I could just kill the humidity ( I live in Dallas TX) it wouldn't be so bad in the shop. It did drop the humidity, but it was still warm / uncomfortable to work out there. A dehumidifier will actually raise the temperature a little - But its a dry heat ... BS doesn't cut it... Took the dehumidifier back.

Then I bought a poratable AC unit for about $400. I think it is about 10,000 BTU. It has about a 5" vent hose to exhaust hot air. I cut a 6" hole in a lower panel on the 3rd bay garage door that I never open and mounted a dryer vent with louvers that blow open. This actually worked sort of OK - It blew hot air out the exhaust and the unit was blowing cold air into my garage. BUT there is a fatal flaw in this setup. The problem is that the air it gets to blow out the exhaust comes from inside the garage. This means that the make up air was pulled from outside into my garage from gaps around the garage doors.

So while you could stand in front of the AC unit and feel cold air blowing on you, it was sucking in hot (humid) outside air to make up for the exhaust air, limiting its effectiveness.

I then decided what I needed was a way to feed warm outside air to the AC unit that it could pull through the condenser coils and exhaust the hot air. I built a prototype box out of foam board and duct tape and attached it to the unit. I fed the box with a 6" duct form outside.

This works great. When I get around to it I am going to fiberglass a more permanent solution, but the foam board and duct tape version actully works well.

A traditional (split) system has two parts a condenser and an evaporator. The condenser sits outside, it uses outside (warm) air to cool hot condenser coils, exhausting hotter air. The evaporator pulls in room temperature air from inside the house and the evaporator coils cool the air and exhaust cold air.

This is the same way window AC unit work - the condenser is outside the window, the evaporator is inside the window.

The problem with most portable AC units is that use room air to cool the condenser and exhaust it out of the room. I have since seen portable AC units with 2 ducts - these are essentially what I modified mine to be, but most of the portable AC unit only have one exhaust duct.

Either find a portable AC unit with both an exhaust and an supply duct, or modify one like I did to add a supply duct you feed with outside air.

I originally thought of trying something like this with a window unit (since a 10,000BTU window unit is $150), building an insulated box that enclosed the back half of the unit and running ducts to supply / exhaust the air.

The problem with this is that most window units don't have that strong of fan to exhaust air. The portable units however usually have strong fans to exhaust the air and can handle exhausting it through a few feet of ductwork - mine has a squirrel cage blower.

I have since bought a second portable AC unit and modified it like the first.

If it is really hot, it can take a few hours to cool my garage down, but then it is fantastic to work in. If I know I am going to work in the garage on Saturday, I just fire up the AC first thing in the morning before it has gotten to hot, and within an hour it is fine.

[capncarl]

GaryA
The insulated garage doors really do work! Not that great, but a real difference over their non insulated counterparts. Have you considered one of the ac's from a single wide house trailer? They are made to just flop on the ground outside somewhere and hose up to the house duct. Used ones are cheap. Thought #2, the early model houseboats used window ac's that were inside the cabins in a nice boxed in enclosure. All that was visible from outside was a louvered panel. They work great, any ac that will fit the box will work and if you want to change size all you do is make a new adapter plate for the inside. I know that just adding another fan is not always the answer, cause nothing attracts sawdust and gnats like sweat.

good luck
capcarl

[FL Buckeye]

If you are a member of Sam's Club, they have units like in your first post. They have a 12K BTU Amcor unit for under $400, and a 12K BTU heat pump model with remote contol and 24hr timer for $570. I don't see the SEER listed on their site. But the return policy is usually pretty good if you don't like it. I would like to AC my hot garage too, but first I would want to insulate good. Now I am only able to really use it in the mornings without the heat getting to me.