I need a dehumidifier for the garage. We've had loads of rain, and therefore mold and mildew. The area I need it for is about 6000+ sq. ft. Also, things like car interiors, leather, etc., is there some kind of airborn spray that kills mold? I'd like a dehumidifier that I can hose drain outside. I know there are industrial, commercial ones but I'm trying for best bang for the buck without an ongoing expensive electric bill. One problem here is I also have a bathroom, shower, laundry room, wash tub so water is used inside garage. I have a center upstairs cupola and end vents, but no fans. Thanks in advance.
What he said, plus you need lots of air circulation (movement). With 6000 square feet, you'd be using dehumidifiers all over the place.
Dehumidifiers are basically air conditioners that collect the condensation. It may make sense to see that the building is insulated, sealed and install a cooling system to dehumidify the air or better yet consider a decent HVAC system. There are good HVAC systems that will control humidity, cooling and heat. I installed an HVAC system for a large computer room that cooled the air into the unit to drop humidity and if needed it reheated the air to maintain the thermostat temperature in the space. I would suggest some ceiling fans to mix the air as well. A good HVACsomeone for that size may require someone who does commercial heating cooling systems.
All I know is that after I purchased a $289 dehumidifier for my 1200 SQ FT shop, I found the exact same unit at a second hand store a week later for $50. Try to buy used if you can. (The unit works very well by the way.) Another interesting aspect of this is that when I got my shop, I had a local carpenter put a 400 SQ FT mezzanine in it. He used "Green-Treated" lumber. The first couple of summers I had it, the dehumidifier ran 24/7. Nowadays, it only runs when I open the main door on humid days. I have talked to a number of folks who say the "Green-Treated" lumber has a LOT of moisture in it. Just something to be aware of.
I agree that for 6000 sq ft you need some type of commercial/ industrial unit. I hav a 1000 sq ft and I got a small portable one from Home Depot that works great. It has about a gallon and a half tank on it and in the summer I dump it every day. I t doesn’t run at all in the winter but I have no other moisture causing (bathroom,sink,shower) appliances.....Mark
It amazes me how many people do not have Dehumidifiers in their Ba*****ts! It will run all year long, through the Winter, which illustrates how much moisture there is below grade. So why not have one in your garage? I agree, that any major moisture issues need to be addressed, but a dehumidifier is cheap insurance. Any Home Center unit will suffice. I've had the same Home Depot unit in my ba*****t for nearly 30 years.
I was told to save the water from your dehumidifier. It is distilled. Save it for your car cooling system. If you are getting a gallon a day you would have a good supply for all your friends. As far as where it comes from questions. Here in northeast PA we have had an exceptionally wet year. You can have your place sealed up all you want. It is in the air and just gets in. If you have no ac in the building it is prob actually better to have it open so the air moves thru it.
Thanks for suggestions. About a year ago I hired a remediation contractor to renovate my 1940 built grandparents vacant home. They had these very large industrial dehumidifiers running 24/7 and sprayed some chemical there for mold and mildew. I went in there one day and it was super loud. After about a week or so and they replaced bad lumber, flooring, etc., it was like a new house. I keep a dehumidifier running there and in house here as well (70 pint). The garage has weird effects depending on weather. One night the fire alarm went off...inside was like a huge cloud of moisture. There are six garage doors, two walk in doors. I'm thinking air flow may help, and maybe I could find a used large dehumidifier.
Many older Garages were dirt floors, and cement slabs were poured later. I've been in the Home Remodeling business forever, and often have to repair garages because of that scenario. Often the wood sills are encapsulated in the cement, and rot. It sounds like your floor slab has issues ***ociated with that. Probably no stone or vapor barrier before the concrete was poured, directly over dirt. In that case, there's little you can do, short of breaking it up and doing it right.
Thanks but no, I was here when they poured cement. They did extensive prep before garage floor poured. Floor stays dry. Long story, but my house is on a hilltop, which is great. I should have built garage on that same ridge. Instead, I wanted it at least 200-300 ft away, but decided downhill. I had, I forget exactly...but 50-60 loads of fill brought in, but it's still about 5ft. lower than house. Problem started when I had everything asphaulted. It goes up to cement sidewalk which goes into concrete floor. Excavator neighbor and I trenched in about 8" along, goes from zero to about 6ft down around over hill. We put in drainpipe and stone. Worked great for years, but that gets leaves, etc. Now I have it all working pretty well, except we get these 3" in an hour downpours! Today I had exterminator out (#@$&#@ stink bugs!) and he saturated house and garage. I installed a big fan in cupola which blows out. When you walk in door you feel the breeze. Hopefully that will help, as well as I'll get maybe a few dehumidifiers.
They're not cheap, but this is a good commercial duty dehumidifier that works well in large spaces, and it simply plugs into a regular 120vac outlet. https://www.sylvane.com/quest-hi-e-dry-120-dehumidifier.html
This same topic gets brought up time after time over on the garage journal forum and lots of times seems like the answer IS, you do not have a "vapor barrier" in you're building so the outside damp air can get in if its not coming up from the ground, insulation (spray foam) is usually the fix all be it expensive. On occasion in my all steel shop (1200 sf) I have this same situation that can occur, my plan is to drop $4k on spray foam, once done I can cool or remove moisture (dehumidify) from the air space much easier, YMMV
I just thought of something else that's probably a problem. I have some huge oak and maple trees around garage. I have to cut limbs that get too close to roof, but even in hot summer the shade makes it seem air conditioned. I really don't want to have them cut down, but the areas closest to trees with the most shade have the most mildew.
Yep depends on your location. Here on the Gulf coast absolutely have plastic under the slab. They sweat unbelievably in the fall and spring when the dew point gets close to ambient with 80%+ humidity. As far a dehumidifiers we just use AC units. Two birds.
remember, moister goes to cold. when it is hot and humid out, keep the garage closed down tight. opening the doors will pull the moister in. when it is cool/ dry out open the doors, it will pull the moister out. i had a friend battling with a damp ba*****t. he had the windows open a fan going and a dehumidifier, still couldn't keep up with the humidity. i suggested he close the windows. he said it wouldn't work but it did. the humidifier could keep up without all the moister being added daily.
If you use dehumidifiers then it doesn't seem like a good idea to also add extra ventilation, as you will simply be removing the dried air. I tried using a dehumidifier in my ba*****t in the winter but it didn't work because it's too cold (I'm guessing about 55 to 60 F.). Where I live we have dry summers and wet winters, which require different approaches to a place that has the reverse rain patterns. If you are heating the building, or live in a warm climate, you won't have my problem. Also try venting the bathroom and laundry room outside when in use, so the moisture doesn't travel to the main area.
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