Portable A/C for Garage... venting w/o window?

[DogP]

So... I picked up a portable A/C that I plan to use in my attached 2 car garage when I'm working out there during the summer ( http://www.sharpusa.com/ForHome/HomeEnvironment/AirConditioners/CV2P10SC.aspx ). A typical installation vents it out a window, but being a garage, I don't have any sort of ventilation except a man door and the garage door. Of course I don't want to run the A/C with either of those open. I could also imagine using this hole to vent fresh air for painting, welding, etc.

Any suggestions on adding a small vent to run the vent hose to the outside? I was thinking I could add something like a dryer vent hole in the wall, but I'm not sure I want to permanently cut through the outside wall and siding for that. The other thought was to add a "doggie door" kinda thing to the man door to run the vent hose out of. That way I'm just modifying the door instead of the actual garage. I don't ever use that door, so there wouldn't be any inconvenience of it being blocked with a hose attached to it. The door also has a window in it, which maybe I could cut and add a vent hole to.

Anyone done anything similar, or have any ideas?

Thanks,
Pat

 

[sirsloop]

I personally just stuffed two 12k units in my rear windows. You may want to reconsider the portable, and get something more permanent installed.

IDK about your garage, but mine here in NJ gets hot as hell in the summer and I NEED 24Kbtu to cool it down. One 12k unit barely took the edge off last summer. I doubt a 10k portable will be sufficient unless you are wheeling it around blowing the output right on you.

 

[JimVonBaden]

For an average 2 car "attached" garage a 10K unit will probably be enough to make it bearable. Use a dryer vent with flaps to vent the hot air out. That is just a 4-6" hole, and easily covered when not in use.

I too am getting a similar unit.

Jim

 

[lzenglish]

Is your garage ceiling sheet rocked in? If it is, you could dump the condensing air into your attic space. If it is not rocked in, you could run a flex duct to one of your attic soffit vents, much like a bathroom fart fan is piped. Just make sure the run is not too long, as per the manufactures recommendations, or your unit could run a high head pressure.

Wayne

 

[BoostAddiction]

I have a vent in one of my garage doors that I use to run exhaust fumes out of in the winter- you've no doubt seen these in commercial shops. If you had a standalone unit with a 4" duct hose, you could use the same kind of vent to duct the hot air from the AC. I've been in customer sites where they had spot AC units that were quite effective, very portable and relatively inexpensive. Ducting the waste heat was always a problem for them in a conventional building, but using vents like these would solve that problem. Here is a link for one type: http://www.sanfordandsondoors.com/CLEARANCE_SALE-Miscellaneous_Sale.html

 

[koditten]

How big is this shop and is it well insulated?


I tried the portable unit version in my insulated shop and it didn't work for ****. I hated having those hoses running all over the place. I hope you got a deal on it.

When I was using mine(about 2 weeks), I didn't want to cut holes in the wall or the overhead door. I did cut a hole in my man door. It was easy to change out the man door when I found out it wasn't working.

I can't even give mine away.

Good luck

KO

 

[DogP]

IDK about your garage, but mine here in NJ gets hot as hell in the summer and I NEED 24Kbtu to cool it down. One 12k unit barely took the edge off last summer. I doubt a 10k portable will be sufficient unless you are wheeling it around blowing the output right on you.

My garage gets hot, but not usually unbearable. It's north facing, attached, and fairly insulated. My 12000 BTU heater worked REALLY well this winter, so I figured comparable cooling should work pretty well too.

For an average 2 car "attached" garage a 10K unit will probably be enough to make it bearable. Use a dryer vent with flaps to vent the hot air out. That is just a 4-6" hole, and easily covered when not in use.

You're probably right, a dryer vent really wouldn't be a big deal.

Is your garage ceiling sheet rocked in? If it is, you could dump the condensing air into your attic space. If it is not rocked in, you could run a flex duct to one of your attic soffit vents, much like a bathroom fart fan is piped. Just make sure the run is not too long, as per the manufactures recommendations, or your unit could run a high head pressure.

That's a really interesting idea... it is sheet rocked in, though the ceiling is over 10ft high, and there's a bedroom above most of the garage (the area that'd vent outside is at the front of the garage right above the door, so I might have clearance issues w/ the door).

I have a vent in one of my garage doors that I use to run exhaust fumes out of in the winter- you've no doubt seen these in commercial shops. If you had a standalone unit with a 4" duct hose, you could use the same kind of vent to duct the hot air from the AC. I've been in customer sites where they had spot AC units that were quite effective, very portable and relatively inexpensive. Ducting the waste heat was always a problem for them in a conventional building, but using vents like these would solve that problem. Here is a link for one type: http://www.sanfordandsondoors.com/CLEARANCE_SALE-Miscellaneous_Sale.html

Ah, like a dryer vent, but latching.

How big is this shop and is it well insulated?

I tried the portable unit version in my insulated shop and it didn't work for ****. I hated having those hoses running all over the place. I hope you got a deal on it.

When I was using mine(about 2 weeks), I didn't want to cut holes in the wall or the overhead door. I did cut a hole in my man door. It was easy to change out the man door when I found out it wasn't working.

I can't even give mine away.

Good luck

KO

I would have taken it. I got it at Costco for ~$340, and they said there's no problem returning it if I don't like it. My garage is only ~18'x20'.

I really wanted a portable unit for a couple reasons. One, I don't have anywhere to put a window unit in the garage, and I don't want to cut a huge hole in my garage (and window units aren't allowed anyway due to the HOA). Also, I have a large collection of arcade games and pinball machines in my basement, and when I have a party, it gets pretty hot with all the games running (~10kW) and people down there, so I'd like to supplement it with an extra A/C.

Thanks for all the input and ideas!

Pat

 

[Steevo]

http://www.grainger.com/Grainger/AM...J2&srccode=cii_13736960&cpncode=33-48552908-2

http://ddmgaragedoors.com/parts/exhaust_ports.html

 

[larry_g]

I got one of these AC units for free. I don't use it as it has to have make-up air from somewhere if it is to work. That make-up air has to come from outside the conditioned space so it leaks in from the hot outside. So instead of using outside air to move across the coils to remove heat, as in a window unit, you are using cooled air from the inside.

lg
no neat sig line

 

[sirsloop]

If you want it done right, I would Install somthing like a one zone split system. It'll be more (a lot) more money up front, but it will pass your HOA BS, look great, run quiet, and won't get in the way while you work.

 

[JimVonBaden]

If you want it done right, I would Install somthing like a one zone split system. It'll be more (a lot) more money up front, but it will pass your HOA BS, look great, run quiet, and won't get in the way while you work.

A split unit would be great, but at 5 times the cost, and for occasional use, not cost effective.

Jim

 

[sirsloop]

agreed, but figured I would put it out there.

 

[Harikari]

This is how i did it and it does an adequate job with my 16 x 22 insulated garage.

 

[JimVonBaden]

This is how i did it and it does an adequate job with my 16 x 22 insulated garage.

Cool, that is what I had in mind!

Thanks,

Jim

 

[VHF]

Is your garage ceiling sheet rocked in? If it is, you could dump the condensing air into your attic space.

Don't do that! I think most (all?) of those roll-around A/C units sling the condensate against the hot condensor coils so it is evaporated and the moisture goes out the hose along with the hot air. You probably don't want all that water vapor exhausted into your attic space!

 

[Steves32]

FYI- The 2 hose models work far better than the single hose models.

 

[DogP]

This is how i did it and it does an adequate job with my 16 x 22 insulated garage.

Ah... that looks really nice, thanks for posting that pic!

FYI- The 2 hose models work far better than the single hose models.

Yeah, I was thinking about that, and noticed that the one I picked up has a port for an inlet hose, but no actual hose (so it just draws the inside air). I guess the problem is getting enough seperation that you're sucking in outside air, but the hot air you're blowing out.

Pat

 

[ameribuiltsteel]

I didn't want to jump on the bandwagon and discourage you, but everytime I've tried a portable A/C unit it's ALWAYS end in disappointment.

That said I did end up modifying my garage down here in Florida and knocked a hole through the cinderblocks and basically did a permanent installation of a window unit. It is enough to take the edge off the heat, but frankly it still *****.

What we are going to do now is replace our A/C unit and add a separate dump into the garage that can be opened and closed. The hole that I've made in the wall is going to have a simple shop fan installed in case I need to vent air out.

I wish you the best of luck though and try something out with that unit soon so you can still bring it back if you are unhappy.

 

[22lover]

I am considering either an 8000 or 10000 BTU portable for my 2-car garage. I have no windows so standard window AC's are not in the cards. I don't want to cut a hole in my wall and outside masonry due to the HOA and such an installation being very visible to my neighbors.

I have 2 insulated walls and of course a non-insulated garage door (which I will be insulating) and one marginally insulated wall to the Southeast.

My goal is not to hang meat or provide the gusto that my central A/C pumps out into the house....but to make it more comfortable to work in (maybe 80F or a bit lower) in the hot, sometimes humid, Dallas summers. I know I could step up to a 14000 or perhaps higher unit but want to be able to power other things with my 117VAC garage service. Unfortunately to get more juice (including 220) to the garage I have to install a new subpanel which is prohibitive at this time.

Anyone go for a portable in this BTU class in a hot climate with success being defined as described above?

 

[JimVonBaden]

22lover,

There is no way to use a cooling unit without venting the hot air. If you can, a dryer vent sized hole, through the door maybe, would be your best bet. Then a semi portable unit as described above.

Jim

 

[22lover]

22lover,

There is no way to use a cooling unit without venting the hot air. If you can, a dryer vent sized hole, through the door maybe, would be your best bet. Then a semi portable unit as described above.

Jim

Hi Jim, yes I understand that. I should have been more clear about the hole I don't want to/am not permitted to cut... which would be one the size of a window unit. I can cut (discreetly) a dryer-vent type hole for a portable unit.

-Bill

 

[CoconutPete]

I used one in a 3rd floor bedroom years ago, it did a decent job but took a while to keep the place cool.

We also put one in my buddies shop - used the dryer-vent method for that one since he had no windows in the back.

In my experience, the portable units "take the edge off" but probably won't get you down to house temperatures.

 

[DogP]

Just an update... I used it one day for about 3 hours. It was ~90F outside, and there were about 10 of us hanging out in the garage. The A/C seemed to keep up just fine... it was very comfortable in there. I just left the man door cracked, with an aluminum flex hose blowing the hot air outside.

Then I decided to get the basement set up for the party I was having later, so I wanted to get the extra cooling ready down there. Two of us carefully moved the unit to the basement, and it wouldn't turn on. I tried everything... GFCI on the cord, different outlet, draining the water, etc... it was totally dead (no lights or anything). Probably some internal fuse or something, because even waiting until the next day it was still dead. So, back to Costco it went.

Now I'm kinda back to where I started. I was happy with the performance, but I don't think I want that same model again, if it dies that easily.

Pat

 

[deter]

Consider a window unit that is cut into a designated opening in your garage wall. This is a permanent mount. They make units that have heat also. My father's shop has this exact setup and it works great year round.

 

[fromnwmt]

I have had one of these for 3 years i can tell you the shorter and less restricted you can make the vent hose the better it cools i was venting it thru the window screen and by chance decided to try it without the screen because it was not doing a very good job it made a noticeable difference, as said before you must vent it outside the air is hot & moist also take advantage of the hose hook up to drain the water it needs drained daily easier to let it drain 24-7 i am still not real impressed with their claim of 10,000 btu but we live in Montana and bought this in the fall on clearance for less then half price..

 

[22lover]

I went ahead and ordered a 14K BTU portable to see how it'd do. It is a dual-hose type. Should be here in a couple days. Insulating the garage as well. Hoping it will work out but will soon find out for sure....

 

[blatterjr]

Just an FYI, Sanyo single splits start at $950 (not installed) for 9k Btu with the 12k Btu going for $1200. Relative to the $500 you'll pay for any decent portable unit.

 

[JimVonBaden]

Just an FYI, Sanyo single splits start at $950 (not installed) for 9k Btu with the 12k Btu going for $1200. Relative to the $500 you'll pay for any decent portable unit.

A 10K BTU portable unit is about $400, and no install fees. Even at $950 for a mini-split, you have to add a similar amount for installation, so about $1900.

Just keeping it real.

Jim

 

[pseudorealityx]

A 10K BTU portable unit is about $400, and no install fees. Even at $950 for a mini-split, you have to add a similar amount for installation, so about $1900.

Just keeping it real.

Jim

But one of the options actually works worth a poo...

 

[JimVonBaden]

But one of the options actually works worth a poo...

Maybe, but there have been reports of the portables working just fine. For that matter, a window unit is cheaper than a portable and works even better than a portable. But the portable is the point of this thread, in case everyone forgot.

Hell, why not get a central air set-up if we are ignoring the OP's point?

Jim

 

[MikeN]

For almost $1K for a mini-split, why not use a full size split?

Can pickup a 13 seer, 4 ton split system with heater for ~$1600 if you know where to look

 

[DogP]

One more update... so I decided to watch Craigslist for a cheap used portable, rather than buying another (expensive) new one. They were hard to find during the 100 degree days, but we had a break in the heat for a week and I grabbed one for $75.

I finally got around to cutting the hole in my door and putting in a vent. I was looking into the actual garage door vents like suggested earlier, but after reading some reviews about them not sealing air well, rattling, and suggestions of only getting the latching one (which are more expensive), I decided to just go to Home Depot and install a 4" dryer vent. They were cheap, and don't really look out of place on the side of the garage (not that it really matters, being right by my trash can).

The parts that I used -
Outside Vent: http://www.homedepot.com/h_d1/N-5yc1v/R-100018300/h_d2/ProductDisplay#.UEhbk9n9UY4
Draft Blocker (hopefully keeps air from coming in when the A/C isn't used, and gave me a nice bulkhead to connect the inside hose to): http://www.homedepot.com/h_d1/N-5yc1v/R-100055473/h_d2/ProductDisplay#.UEhbmdn9UY4
Semi-rigid hose (the unit I bought didn't have the original hose anymore): http://www.homedepot.com/h_d1/N-5yc1v/R-100034844/h_d2/ProductDisplay#.UEhbn9n9UY4

If doing this, make sure you get the semi-rigid hose... I initially used the standard dryer hose (like: http://www.homedepot.com/h_d1/N-5yc1v/R-202305921/h_d2/ProductDisplay#.UEhbiNn9UY4 ), but the air flow is greatly minimized through those, and it was causing my compressor to shut down after running for just a couple of minutes.

It hasn't been that hot out there since I've installed it, but it seems to do the job well enough for now (and dehumidifies well). I really just wanted something to make it bearable to work in there during the summer, and I think this will work.

Anyway, thanks for the help and tips... and hopefully this helps in case anyone's looking to do something similar in the future.

Pat

 

[briantompo]

...hopefully this helps in case anyone's looking to do something similar in the future.

Thanks, Pat for following up and not leaving the thread hanging. It IS a big help when the next guy is doing research and comes across this thread. Brian

 

[Rantz]

I went ahead and ordered a 14K BTU portable to see how it'd do. It is a dual-hose type. Should be here in a couple days. Insulating the garage as well. Hoping it will work out but will soon find out for sure....

Hey everyone, sorry to resurrect an old thread, but I joined the site just to help make my decision regarding this situation and this is my first post.

22Lover and others, how did it work out for you? Which method of venting did you go with? I ask because I'm in Hot/Humid Florida and am finally going to do something about it this Summer even though I have no windows. I'm trying to avoid the cost of a mini split system. I've got some big woodworking projects planned for this summer (Finish custom stairs in my house and building the majority of my grandmother's new kitchen cabinets) and would like to do it without being miserable in the heat despite having two fans pointed at me.

I know that I definitely want to go with the 2 hose models. So I'm torn on venting options:

1. Two Dryer Vent type holes through the cinderblocks and stucco of my garage? I'd prefer to avoid permanent holes.
2. Or a vent to the small isolated garage attic straight up? Then there'd just be drywall to patch if necessary.

• This may need to include some way to vent through the vinyl soffit to help avoid adding any hot/moist air to the attic as my online research has indicated is a concern for leading to mold and rot of the wood. And/or I could install a solar attic fan to help cycle new air into the small attic space.

Some background info:

To make the installation as discreet and HOA friendly as possible (and I'd prefer to avoid permanent holes in the cinderblock wall), I'm looking at Portable A/Cs as my main option. My goal is to run both vent hoses to the ceiling of my garage to the attic space. That way it's just two holes to patch in drywall should I ever need to uninstall.

I am leaning towards purchasing this unit from Amazon (http://amzn.com/B002W87P9C). I would like to make my garage workshop much more enjoyable to work in during the often HOT weather of Florida. This unit is rated for WAY more than just my ~200 sq. ft. garage.

• I live in sunny/hot Florida
• I will be using this in my (cinder block construction) one car garage workshop that measures about 10' x 20' (so ~ 200 sq. ft)
• 9.5 ft high drywall ceilings with NO insulation in the attic currently.
• I am in the process of insulating my metal garage door now with rigid foam backed radiant barrier material. I'll next finish it up with a thin panel of the whiteboard'ish thrifty panel from Home Depot that'll give me a ton of dry erase brainstorming/note taking space. The weight of the foam is negligible and the whiteboard'ish panel's weight shouldn't be an issue for the garage door opener.
• I will eventually insulate the VERY cramped and small attic space above the garage that is currently not insulated most likely with some roll out fiberglass insulation. I imagine this will make a huge difference as it is hot as Hades up in that tiny attic during the day. Unfortunately it's so cramped, it will be very tedious and a PITA to get to all portions to insulate it. May have to resort to just shoving insulation into place with a poker of some kind
• The garage is finished fully with cinder block walls and a drywall ceiling and the garage is attached to the house (garage's attic is NOT attached to the rest of the house's attic as the garage is one story high and the rest of the house is 2 stories high). This is what has me not as concerned about venting to the tiny garage attic as it won't have an effect on the rest of the house, but I still don't want mold/rot there either.
• The garage has vinyl soffit running all around 3 sides with all of the holes in it, but has no ridge vents like the main upper roof/attic does. So it seems there's probably poor circulation of air in it as of now, but I was originally thinking that the soffit would allow enough air to pass in/out if I was just venting into the attic and not to the soffit.
• I'll most likely wrap some reflectix insulation around the hot exhaust hose.
• I'm relatively handy and am comfortable with all of the basic home repairs and renovations and do my homework/research where necessary to fill in gaps or learn new things.
• If necessary, I may look into putting in some kind of solar attic exhaust fan that will draw the hot air out of the small attic space (I may do this anyway for the main house's attic above the 2nd floor to save on cooling bills).

Thank you for your time everyone. I needed to sound board and get some advice/suggestions/thoughts on this.

 

[Rantz]

Well I made my decision and ordered everything. I'm just going to **** it up and cut two dryer vent type holes for the 5 inch diameter hoses through the cinder block wall. Technically those can be patched if ever necessary.

In case it helps anyone else looking in the future, here's what I'm going to do.

The following things got ordered from Home Depot (had to order from online since the 5" size is rare):

• Flexible insulated 5" duct
• 5" metal duct section (for the passages through the cinder block
• Expanding/insulating foam (for around the metal duct in the cinderblock)
• HVAC Foil Tape
• Masonry blade for 4.5" angle grinder

From Amazon:

• Whynter 14,000 BTU Portable Dual Hose Air Conditioner: http://amzn.com/B002W87P9C
• Square Trade Extended Warranty (for an extra 2 years of protection after the manufacturer's warranty expires)
• 6" Fixed Louvered air intake vent cap. I had to get the 6" since 5" didn't exist except from a random company online that I couldn't tell fully whether it was fixed or not. Since I'll have an intake hose, I need the louvers to stay open on that port at least. So I'll just seal around the metal duct on the exterior of the house and then just surface mount the 6" louvered air intake over the entire hole and not actually attach it to the intake vent cap.

I'm just going to use the insulated ducting that I ordered instead of the plastic accordian type hoses it comes with.

 

[Syberia]

I hope you have better luck with that supposed "14,000 BTU" portable than I did. Mine got sent back within a couple days; I bought it for my office (~150 sqft, so the unit is terribly oversized already) and it could never get the room any lower than about 80 degrees, even running nonstop. Sometimes, with the A/C running and outputting cold air, the temperature on the thermostat actually increased.

I replaced it with a lower-rated (8,000 btu) window unit that actually performs much better.

 

[gtpinoy]

Sorry to bring this thread back up, but does anyone that has completed a portable a/c unit install have any feedback?

 

[Rantz]

Sorry to bring this thread back up, but does anyone that has completed a portable a/c unit install have any feedback?

I had to run it almost constantly in my one car garage, insulate the garage door, insulate the garage attic, to be able to feel it made a great difference. It was important to start it in the morning before the garage warmed up. I found it odd that it had a slight amount of negative pressure so I left the door to the house cracked to **** that instead of possible outside air. It did cool things, but I later had decided I'd have been better off with a mini split system. Window units weren't allowed in that HOA.

I've since moved and still have the a/c, but it collects dust as my new garage faces a new direction and doesn't seem to get as hot.

I just taped up the ports in the old house garage and buyer never said anything or cared. It looked tidy. People assumed it was for a dryer (didn't click for them that there were two vents and not one).

 

[American Locomotive]

If it's much over like 75°F, a single-hose portable air conditioner will actually make your home/room hotter. The single hose units blow a ton of hot air outside, but that air needs to come back in the room from somewhere.

Where does that air come from? Outside. All the little cracks and crevices in your home allow hot humid outside air to replace all the air that portable unit is blowing outside.

I don't even understand how the single hose units are even legal to sell. They're junk and just waste power.

 

[Rantz]

My experiences, if you read above, were from using a dual hose unit. Then again, you may have just been speaking generally.