dehumidifiers

[gnj588d]

Hi everyone.Thinking of getting a dehumidifier,do they work in a garage enviroment i.e. not a seeled room or is it a waste of money  Many thanks  Mike.                                         

[PnHi]

I keep one in my basement in the summer and empty several gallons of water a week.  Seems like it would help.

[DaveB]

I can't help directly but it is something on my to-do list. I bought a swap meet dehumidifier & intend to try it out when I have power to our shed. I don't believe you'd need to run it all day, only during the period when temperature drops below the dewpoint. That would typically be about 3-6 am where I live, depending on weather conditions of course. I have access to a logging hygrometer so will evaluate whether it actually works. It probably wouldn't hurt to seal your garage to some extent although you'd want to keep some openings for ventilation. Storing some dry conifer or balsa timber in your garage will help take up airborne moisture and a dessicant like silica gel or even salt, stored with your steel tools & parts will also help keep them rust-free. I also use a spray on lanolin oil product, Lanotec, on steel tools. A light spray dries to form a protective coat. I hate rust!

[DavidBrough]

I purchased one about two years ago and it works very well in my slightly draughty garage. There used to be quite a lot of moisture and damp but now it's as dry as a bone. I ran the machine constantly for the first 3/4 months but now only switch it on when the temperature drops. It's an X-Dry dessicant unit which cost about £175 and my garage is about 25x30 feet.

[johnd]

I have a pretty good size garage/shop now (2600 sq ft) and bought a few cheap ones from a guy selling them on ebay (here in town so I could pick them up).  I don't run them all the time, but LOVE them when it is really humid, or the old roof leaks.... I can set them to come on if it gets too humid, so set them and forget them.  The shop has drains so it makes it easy for me to run hoses in some cases, and not empty buckets. When you see how much water they remove, you'll really appreciate them.

[France]

Hi Guys,

Several years ago we realized we would have to battle back at the hot wet Florida summers.  Once it reaches June, we have 90% humidity, and the garage is closed for the summer until November when the dry air comes.  We got Home Depot's top model and installed it to go on at 65%, draining through a short hose under the garage door--by no means a sealed environment!  It has worked *great* for three years and made a world of difference.  There is no mold at all.  Home for Easter!!!

[abe280SL]

Glad I live in SoCal...we don't have those problems.  We only have little problems like unemployment, taxes, and more debt.... :othank goodness I don't have dish out money for a humidifier....that can kill my wallet.
abe

[benzportland]

I bought one for the one car garage portion of my three car garage.  It is a relatively small area, and has a closing garage door although it not exactly "sealed" like a house of course.  I live in Oregon, so we have lots of rain but not the kind of humidity you really "feel" like in the midwest for example.  I did notice though that in the Winter, a film or "sweat" of moisture would blanket my car around noon, when the temps went up.  I got a Soleus CFM-40E, after doing consumer research, and have been happy with it.  It is removing about 50 pints of water a week on average over the past three months I have used it.  I am guessing it has raised my electric bill about $20 per month, but I have it always on.  I have noticed that the car no longer has the moisture on it, and, the air in general in the garage seems much cleaner.  The interior of the car seems fresher too, at times it had that musty old leather smell.  The Soleus price range is anywhere from 160 to 250 dollars depending on where you get it, I got mine through Amazon. 

** On mine, the only automatic shut-off is when the temp is too cold, and when the water collector bin is full.  There is a hole to hook a drain hose in, but the hose itself is not included with the unit. 

[Cees Klumper]

We run one in our Amsterdam basement and it's made a marked improvement in the humidity. I will also get one for the garage shortly.

One thing I noticed about the posts here: the manual switching on and off. The one in our basement switches itself on and off automatically depending on the ambient humidity (you can pre-select the humidity swiching level), and I have it hooked up to the plumbing, so no need to empty a container etc.

[JamesL]

A dehumidifier in an Amsterdam basement is known to the rest of us as a "pump"

Amazon have a decent selection, many of which have a constant drain. I'll be getting one before long

[knockmacool]

Cees,

What is the make of your dehumidifier? We run a manual, and do have to empty it, in our basement. Does the job well, considering the water level in the well outside is only 5 ft below ground sometimes. Just finishing my garage and need to have something out there for the winter (not dissimilar to Oregon!) Given the slope of the land, one of the garage walls is already three foot underground (not my design, some crazy irish farmer 200 yrs ago) so dehumid is a must

[Cees Klumper]

It's an EBAC; here is a picture of the very unit. And, yes, Tosh, we do live a couple of feet below sea level and the basement is a few feet lower than that - so we do also have a pump in the basement that automatically switches on to pump ground water that sits in our basement well (I kidd you not, there is a real well in the basement, with a wooden lid on it. The house is from the 1700's). But with the dehumidifier, it's all quite dry.

[mdsalemi]

Well, Ladies and Gents--you didn't think I wouldn't eventually have SOMETHING to say here??

The only real functional difference between a dehumidifier and and what we call an "air conditioner" is what it does with the reject heat; the reject heat is a byproduct of the process.  Both operate identically using compressors and condensors and the transfer of "Freon" like chlorinated hydrocarbons between the two, and between the two states of liquid and gas.

Here's the issue: warm air holds more moisture than cool air.  So, if you use a "dehumidifier", you are simply removing the moisture from the air, but increasing the temperature of the room in which the unit works--unless you have it set somehow to reject that heat elsewhere.  That increase in temperature means the air can hold more moisture; yet reducing moisture is what you are looking to do!

Bottom line?  If the room you are "serving" by dehumidification can stand reduced temperatures, an A/C is probably the way to go.  Wall a/c units and even portable a/c units with a remote "air dump" are available...if storing my car, I'd rather have it at a cooler temperature than a warmer one with reduced overall moisture and relative humidity.  Cold storage?  Works for meat, for furs, for food, and even dead bodies!    Warm storage? 

Keep in mind that there are plenty of inexpensive dehumidifiers and a/c units out there that are extraordinarily expensive to run due to their inefficiency.  Pay attention, in the USA at least, to Energy Star ratings, and efficiencies before you invest.  If you save some money up front with a cheap unit you will surely pay that savings to your electric utility in short order...and continue to do so.

When you invest in either a dehumidifier or an A/C unit, also spend a bit (they cost about $10 here) in a little digital temp and RH meter so you can actually see what you are doing.  You may be removing "18 pints a day" of moisture from the air, but if you are not affecting the overall RH of the room, why bother?

I have a room in my home with an acoustic piano in it (pianos like 40-45% RH); I have a room humidifier that adds about 6-12 GALLONS of water a day to the air.  Yet, despite that addition, it is hard to get the RH at 69 degrees F to more than 38%.  If I don't add that water it drops to about 20%--during heating season.  During the summer cooling season, the a/c unit will keep that RH in the low 30% range but no lower.

[gnj588d]

Thanks for all the help it was most helpfull,and quite fascinating know what I am looking for now.  Thanks again Mike Rutledge.

[graphic66]

You can also put an open bag of lump charcoal inside your car. It is a good desiccant and Oder soaker. I use a tupperware container to put my charcoal in on the floor of the car. I also cook with it so I keep it rotating out during storage. A side note for all you "grillers", lump charcoal is eleventy billion times better at cooking food than charcoal briquettes or gas. It starts incredibly quick and has no strange chemicals like briquettes. After your done, shut down the air on your grill, it goes out and next time you just add a little more coal and your ready to go!

[Sigman]

Mike S,

I agree.  It's always pleasant to read your informative responses.  I've had the heat issues with using a dehumidifier in my garage.  An A/C unit does a better job.