Dehumidifiers

CSteve

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The average highs for my area according to weather.com are around 41 degrees.
Looking at average lows and highs for my part of Bucks County north of Phila. My math results: Dec through March average highs 42 degrees, lows 31.
Not sure if I need the low temp dehumidifier. Open to suggestions.
Steve
 

autokunst

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Open to suggestions.
I'd suggest putting a hygrometer out there. Ideally a digital unit that is both accurate and also remotely readable (in the house somewhere). That way you can monitor the actual humidity level in the garage. I like to keep the humidity level for storage between 30% and 40% (I set the dehumidifier for 35% most of the time). I would not want to let the RH go above 50% for sure. Once you know where your garage is at, it will be easier to determine if you need to do anything, and if so just how much. :)
 

autokunst

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The average highs for my area according to weather.com are around 41 degrees.

Looking at average lows and highs for my part of Bucks County north of Phila. My math results: Dec through March average highs 42 degrees, lows 31.
Not sure if I need the low temp dehumidifier. Open to suggestions.
Steve
One more thought regarding ambient outdoor temps. The air temp in the garage may be higher, at least at times. We also have a very old (1929) unheated, uninsulated, very well-ventilated garage (visible holes abound). Yet, if the sun is out at all it is noticeably warmer in there than outside most days. If you have a moisture issue, a low temp unit could still make a dent when the temps rise above that 41 degree mark in the garage. Just a thought...
 

Gary Knox

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Steve,

Not sure you need a dehumidifier during the winters here in PA. I've never used one during the winter, but it is great to have during the sticky days of July/August/Early Sept.

Gary
 

autokunst

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This is coming a little late, but here is a document I'd found and referenced when I was researching dehumidification for my garage. Sorry I didn't post sooner...
 

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'69 2800cs

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I use a low temp dehumidifier here in Southern NJ and highly recommend it. My old dehumidifier froze up regularly.

Even with some winter days in the teens here it often warms up to the fifties during the winter and very humid. The swings in temperature bring nasty condensation and so running the DH all the time is beneficial.

I also have a brick garage, a wonderful environment for storing moisture and throwing it back on the cars....I drylocked the interior brick years ago, and a little electric heat and a constant DH are needed for a car friendly environment.
 

Gary Knox

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Thank you Stephen. That chart showing the rapid increase in steel oxidation above 60% RH is amazing. I think one for growth of mold/mildew would be pretty similar!

Gary
 

CSteve

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Thank you Stephen. That chart showing the rapid increase in steel oxidation above 60% RH is amazing. I think one for growth of mold/mildew would be pretty similar!

Gary
I am going with a low temp deh. The humidity during our first snow storm here in SE PA was 93% yesterday. News to me.
Steve
 

JayWltrs

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I use a low temp dehumidifier here in Southern NJ and highly recommend it. My old dehumidifier froze up regularly.

Even with some winter days in the teens here it often warms up to the fifties during the winter and very humid. The swings in temperature bring nasty condensation and so running the DH all the time is beneficial.

I also have a brick garage, a wonderful environment for storing moisture and throwing it back on the cars....I drylocked the interior brick years ago, and a little electric heat and a constant DH are needed for a car friendly environment.

My garage is similar, and in OKC the temperature varies wildly over the winter and within the same day. So, even with static low temp outside, wife brings in snow, rain, etc which pools under her car, etc.
 

JayWltrs

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This is coming a little late, but here is a document I'd found and referenced when I was researching dehumidification for my garage. Sorry I didn't post sooner...

I'm not even going to google to see how much the machines in the pamphlet cost.
 

Gary Knox

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Steve,

Those WET/HEAVY snows that we get early in the winter and late in the winter are usually accompanied by high RH. Finally by the end of today, I think I'll see green lawn again. I've reconsidered, and now plan to continue leaving my dehumidfier turned on and set at 50% through the winter. It simply won't run whenever the RH in the garage is lower than that.

Gary-
 

CSteve

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Steve,

Those WET/HEAVY snows that we get early in the winter and late in the winter are usually accompanied by high RH. Finally by the end of today, I think I'll see green lawn again. I've reconsidered, and now plan to continue leaving my dehumidfier turned on and set at 50% through the winter. It simply won't run whenever the RH in the garage is lower than that.

Gary-
Good advice that I will take, Gary. Which model do you have? My garage is 24x24, 13 foot ceiling, no insulation, brick floor. I want to drain to the outside.
Is yours an energy hog? And where do you place it and do you keep your windows down and car cover on most of the time? I wonder if the mold that formed on the interior was partly a result of all the windows being closed.

Steve

PS: Apologies to the hogs, one of the smartest animals in the barnyard.
 

JFENG

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Despite having a dehumidifier in my car cave, In October I found a few spots of mold on my sisal floor mats. Humidity is kept at 50-60%, car has a breathable poly cotton indoor car cover. I keep the front windows open under the cover. Never had this problem with the other cars but they are uncovered 90% of the time because they get drive more often. No problems in the previous 5 years. But this fall has been the 3rd wettest reorded and I did get very minor water intrusion via the stone walls.

Drain to outside works via gravity or you can get cheapo condensation pump like they put on air conditioner units. I have my humidifier on a 6" stand which lets me run the drain hose fairly far to where the water goes out.
 

autokunst

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Despite having a dehumidifier in my car cave, In October I found a few spots of mold on my sisal floor mats. Humidity is kept at 50-60%, car has a breathable poly cotton indoor car cover. I keep the front windows open under the cover. Never had this problem with the other cars but they are uncovered 90% of the time because they get drive more often. No problems in the previous 5 years. But this fall has been the 3rd wettest reorded and I did get very minor water intrusion via the stone walls.

Drain to outside works via gravity or you can get cheapo condensation pump like they put on air conditioner units. I have my humidifier on a 6" stand which lets me run the drain hose fairly far to where the water goes out.
Sorry to bear that. What's the temp in there John? 60% is actually pretty high in an indoor environment. The covered car, even with a breathable cover, will have no demonstrable air movement down by the floor mats.
 
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Gary Knox

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Steve,

Before having the dehumidifier, I'd stored the car in the hobby garage from mid August through mid-September with the windows up. September of both 2015 and 16 I returned to find mold and mildew on the leather (seats, steering wheel - stored car was a 1990 MB 560SEC both years). That lead me to get the dehumidifier and leave it turned on (runs whenever humidity rises above set RH - I used 50%). The first year, we had a short power outage after about 2 weeks, so the dehumidifier did not re-set and was off the last two weeks. I'd left the front door windows down on the car, and had no mold/mildew. This past summer, left all windows down (car uncovered both years), no power outage so dehumidifier functioned for the entire month. Interior conditions were perfect upon return. Stored car in 2017 and 18 was the 3.0 CS.
 

JFENG

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ok, maybe I forgot to put the windows down one time (too lazy to wait for them to go up/down. Sounds like windows down is still the best way.

Autokunst, I said 60% because I think it varies a bit in my cave (dehumidifier in one corner of a 24x36 room), and I know that sometimes it spikes when a torenntial rain leads to a bit of standing water inside. In those cases, it takes the dehumidifier a full day to dry it out. I'm doing gutters next spring to keep the roof runoff further away from the stone foundation. Maybe that'll help a bit. Your point about lack of air movement has got me thinking that it might be worth while to setup a cheapo box fan on low to keep the air moving a bit in the height of summer.
 

autokunst

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+1 on the fan for circulation (regardless of the RH of the air).
I had an accidental wet garage situation several years ago. In retrospect it was entirely self inflicted, and our stupidity did horribly affect a car (fortunately none that are in the stable currently). But because of that experience, I've become ultra sensitive to the topic, and is also why I dry the living daylights out of our spaces currently. ;)
 

Michael Kaye

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So I’m going to revive this old thread.

Just trying to work out if a dehumidifier would be beneficial for my garage here in London.

The garage is concrete floored and brick.

We don’t get a huge amount of humidity in London but still wondering if it’s worth it.

Temps in London range from around 0 c (32 f) in winter to 25 c (80 f) in summer.

Anyone (especially those based in the UK and similar climates) have any thoughts/advice?

Thanks, M.
 
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