Page 1 of 2 12 LastLast
Results 1 to 15 of 29

Thread: "Portable" air conditioner vs dehumidifier

  1. #1

    "Portable" air conditioner vs dehumidifier

    I have an insulated 2-car garage in Minnesota, where it has recently gotten very hot and humid. I'm considering getting either a dehumidifier or A/C for the garage to keep the humidity down (and potentially to cool the space a bit). My primary concern is avoiding rust on tools - comfort is secondary.

    There is an exterior wall, so I could install either a mini-split or a through-the-wall A/C unit (or heat pump).

    Ideally I'd put in a mini-split, but I already have an electric heater in the space, so the heat pump feature would be somewhat redundant. And I don't anticipate staying in this space long-term, so I'd like to avoid investing that much time/money.

    The work to cut a hole in the wall for a window A/C seems to be more hassle than it's worth.

    I was leaning towards a cheap dehumidifier (~$110), but what about a "portable" A/C? For only a little more cost than a dehumidifier, I'd get some cooling, as well as dehumidification. Seems better than adding ~500W of heat into the garage by running a normal dehumidifier.

    Anyone have any experience with these?

  2. #2
    Join Date
    Jun 2017
    Location
    Landenberg, Pa
    Posts
    200
    I tried the portable a/c unit and it could not keep up with a 2-car garage in PA. They do not dehumidify as well as a dedicated dehumidifier with a built in pump (run continuously) would be, and they're more annoying to empty. I'm running a dehumidifier now after giving up on the portable a/c, but the mini-split is oh so attractive particularly when the heat is as bad as its been lately.

  3. #3
    Join Date
    Apr 2013
    Location
    Kansas City
    Posts
    1,134
    I have a portable in an upstairs bedroom. Not worth it, barely cools. It also doesnt extract that much humidity, as its not designed to collect and hold a large quantity of water. It has a tray on the bottom like a refrigerator, where the water is supposed to mostly evaporate away, which defeats the purpose of de-humidifying. Look carefully before you buy one.

  4. #4
    Thanks, guys. I think I'll just go with the standard dehumidifier, then.

  5. #5
    Join Date
    Dec 2012
    Location
    Hampton, GA
    Posts
    89
    Here's my experience with portable A/C's and dehumidifiers:

    I have had 2. One was an Avallon. It was a dual hose heat pump. Worked fine until one week after the 2 year warranty expired and it expired. It took days to get in touch with customer service. They were willing to replace the compressor under the 5 year part of the warranty, but had no service network. The other was a single hose LG A/C. It pulled make up air in so fast it couldn't keep up.

    Now I have a 6000 BTU window A/C (that is 8 years old) that cools the 600 sqft shop just fine. It also keeps the humidity at around 50%. As you might expect, my advice is run from portable units. Especially single hose units.

    To be fair, I admit to having a dehumidifier for the rest of the basement (~2000 sqft). However, it is closed off from the shop. I've gone through 4 over the years. 2 Frigidares, a GE and an Aprilaire. The first 3 (~$200/each) lasted just long enough to cover the warranty period. The first Aprilaire (~$800) lasted 4 years and was replaced by Aprilaire (it is 2 years old now). Aprilaire C/S is first rate. No argument. Just report some measurements, send in part of the wiring harness and the new unit shows up at the door.

    The odd thing is that the basement is not crazy humid ( ~60-65%). I see bringing it to 50-55% as light duty.

  6. #6
    Join Date
    Nov 2003
    Location
    Central North Carolina
    Posts
    1,501
    For dehumidification just get a good quality dehumidifier and hook it up so it can drain 24/7 or have a small pump to pump the condensation to a drain. Then, if your shop gets too warm in the short Minn. Summer, add an air conditioner. My point is that a dehumidifier will likely need to run 10 or more months a year in a basement and will actually add a small amount of heat to the space, while an air conditioner will also remove moisture from the air, but it will likely only run a couple of months a year where you are, because if left on in cooler months it will be cooling as well as dehumidifying and you won't want the cooling function. You won't get much benefit from a heat pump, because they are only efficient if the outside air temperatures are above about 50 degrees when set to provide heat to your interior space. Save your money and just get an air conditioner if your shop gets too hot in the Summer months. There are less parts in them to break.

    Charley

  7. #7
    Join Date
    Mar 2003
    Location
    SE PA - Central Bucks County
    Posts
    49,201
    Quote Originally Posted by Dan Friedrichs View Post

    Ideally I'd put in a mini-split, but I already have an electric heater in the space, so the heat pump feature would be somewhat redundant. And I don't anticipate staying in this space long-term, so I'd like to avoid investing that much time/money.
    The latter thing is a different situation relative to your decision, but for the former, the MiniSplit is going to be a HECK of a lot more economical to run than the resistance electric heater you likely have now. I left mine hanging for "emergency use", but I don't anticipate ever using it now that I have the MiniSplit which is awesome. Our electric bill has barely noticed the MiniSplit, but when the Farenheat unit was running in the winter, it was soaking up $50-75 of power for very part time use. But if you're likely to move in the reasonable near term...it might not be a good solution because they kinda get "installed" in a somewhat permanent way. Of course, that could be a selling benefit if the buyer is a woodworker or someone who has another "garage related" hobby.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  8. #8
    Quote Originally Posted by Jim Becker View Post
    The latter thing is a different situation relative to your decision, but for the former, the MiniSplit is going to be a HECK of a lot more economical to run than the resistance electric heater you likely have now. I left mine hanging for "emergency use", but I don't anticipate ever using it now that I have the MiniSplit which is awesome. Our electric bill has barely noticed the MiniSplit, but when the Farenheat unit was running in the winter, it was soaking up $50-75 of power for very part time use. But if you're likely to move in the reasonable near term...it might not be a good solution because they kinda get "installed" in a somewhat permanent way. Of course, that could be a selling benefit if the buyer is a woodworker or someone who has another "garage related" hobby.
    Don't make me feel even worse about using that thing! It was free (unfortunately), and I figure costs about $0.50/hour to run. So I avoid it, too. Almost wish I hadn't been given it, as then I'd be better able to justify the mini-split..

  9. #9
    Join Date
    Mar 2003
    Location
    SE PA - Central Bucks County
    Posts
    49,201
    Honestly, going to the MiniSplit for me was predicated by my retiring from full time work last fall and being in the shop pretty much daily. The cost to heat became "eye opening" over the winter and since Professor Dr. SWMBO pays that utility on her side of the budget, I needed to find a better solution. Hence, the new system which I'm extremely pleased with. But I do understand the conundrum!
    --

    The most expensive tool is the one you buy "cheaply" and often...

  10. #10
    Join Date
    Mar 2010
    Location
    Somewhere in the Land of Lincoln
    Posts
    994
    Do you not have an available window to use? That would be the quick and easy solution. If your garage is insulated it will cool easily with a 12-15000 BTU window unit. I think people are associating a portable unit on wheels with a window unit. Not the same at all and that's not the type you were referring to either when talking of roughing in a hole in the wall. If you can put it in a window it can be removed in the fall when no longer needed. I easily cool a 24 by 30 shop with a 15000 BTU unit. I had a 12000 before but it was marginal but acceptable. It was still working but the control board failed so it wouldn't shut off and turned into a big block of ice. I went a little larger with the replacement and it works great but I'm several hundred mile south of you so I'm sure a 12 would meet your needs. I don't have any rust issues as long as I don't do something that causes it. The fact that a dehumidifier is going to crank out heat as a byproduct would be a negative to me. You don't want to make it warmer than it already is. However the choice is yours. I hope whatever you decide works out great.

  11. #11
    Join Date
    Sep 2007
    Location
    Upstate NY
    Posts
    3,455
    I have a portable A/C I got to use with my generator during power outages. Its not much, but better than nothing. If you have 3 interior walls and it is decently insulated, it could keep your garage reasonably cool. It won't be as dry as a dehumidifier for the same electricity, but will be cooler.

    Obviously it won't do a thing in the winter; but the one time I was in MN in the winter it was unbelievable dry, so maybe that isn't a problem for you.

  12. #12
    No window, unfortunately, so it would require cutting a hole in the wall. But I was thinking of the ones that look more like dehumidifiers and use a ~4" exhaust duct to dump the hot air outside.

  13. #13
    Join Date
    Sep 2007
    Location
    Upstate NY
    Posts
    3,455
    Quote Originally Posted by Dan Friedrichs View Post
    No window, unfortunately, so it would require cutting a hole in the wall. But I was thinking of the ones that look more like dehumidifiers and use a ~4" exhaust duct to dump the hot air outside.
    Mine draws room air in and passes it over an evaporator and back into the room. A 4" hose brings in outside air, over the condenser and out a second 4" hose, along with the moisture. I rigged a board with two 4" connector on it that fits in a double hung window. You could just put the ports in the wall. It has a dehumidifier setting also, but I haven't paid much attention to it; I suppose it just doesn't connect to the outside.

  14. #14
    Join Date
    Nov 2005
    Location
    Mid Michigan
    Posts
    468
    I use a portable ac unit in my shop....2300sq/ft & 10' ceiling.

    It's always set on de-humidify mode. It'll pull 5 gallons of water in 12 hours.

    Shop is 75 deg & 55% rh right now....very comfortable.

    A regular dehumidifier will put heat back into the shop......it defeats what your trying to do.

    Ed

  15. #15
    I've had a few portable air conditioners over the years, and they're all junk. They inevitably leak water onto the floor and usually only last a few years before they leak freon and become garbage. Also, if it only has one hose, it won't do much since it's got to suck in as much air as it blows out. The only time I'd consider using a one-hose portable a/c is if I had an attached garage and wanted to steal conditioned air from the house. But it's not a very efficient way to do it.

    A dehumidifier works way better than an air conditioner at removing humidity because relative humidity is relative to temperature. Humidity is highest during the coolest hours of the day when you don't want to be air conditioning. And cooling the room raises the relative humidity. Heating it (which dehumidifiers do, slightly) lowers humidity further.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •