Basement Humidity Level - What's Ideal


Greg@mnrr

Greg@mnrr

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Living in Wisconsin, my Milwaukee Northern is located in my basement where the humidity levels rise during summer. I keep the humidity at approximately 55% during the summer months and it's nearer to 40% in the winter heating season.

Layout owners with basements, at what level do you maintain the humidity during summer?

Thanks.

Greg
 
honestly I don't know but when I lived in new Hampshire it had the same climate as you,& I had new house built & when I built a layout I also bought a dehumidifier , & ran it
24/7 spring summer & fall 1 because of the new concrete & the humidity from the season , but it worked for the 11 years I lived there ,of course down here they have no basements..... grrrrrrrrrrrrrrrrr but that's another rant lol
 
I keep an eye on the relative humidity in my basement, and especially when my layout was in it. The layout is now in a loft above my out-building garage down the lane. It also needs watching.

As air temps rise, it's ability to absorb humidity also rises. When the temps fall, you get more condensation on pipes, or when the pipes are cold, such as when you run your outdoor watering system. As you warm the air, which happens in my basement December through March due to my running a hot wood stove in it, the humidity drops as a reading, but the actual moisture absorption from the pad and walls doesn't change as a rate. When the basement gets cooler relative to the upper floor in the summer, humidity rises. That can affect wood and wood products such as MDF and hardboard/masonite/doorskin. It causes it to swell if the humidity rise is more than about 20% above the former average. When the wood swells, it will pull rail joints apart.

On the other hand, if you had relatively high humidity when you built the layout frame, and then let it dry out in a heated room, the wood will shrink as the humidity is taken up by the warmer air. Shrinking wood will cause hard abutting at the joints as those joints are forced to close further and further until the tracks have to give and they'll bow...up or sideways.

So, what do I do? I keep an eye on both rooms, basement and layout loft, because my wife often lets laundry finish drying in the basment, particularly if it is humid or rainy outside and she can't hang it up. In the loft, I have the lone 16 pint machine set to cycle between 66% and 54% ambient as its built-in humidistat reads it. I have a cheapo $12 temp, time, and humidity digital thingy sitting on the unfinished parts of the layout surface at present, and I often find it disagrees with the machine's readings with a variance of about 4%. At least it's an indication. When the reader shows 58%, the dehumidifier is never running. It can show 68% and the machine still hasn't kicked in. So, I know now to look for the reader showing about 70-72% ambient before the machine will cycle on.

The dehumidifiers are not cheap, but a decent one with a 20 liter a day capacity and a three year warranty can be had for less than the cost of a smaller BLI steamer with sound.
 
I really don't pay much attention. I live in Montana and our humidity is usually low in about the 20 percent range. My track is mostly hand laid on Homabed roadbed and I haven't had a single issue with it in to over 20 years it has been in operation. Guess I'm lucky in this respect.
 
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That's been on my mind, also living in Wisconsin.

We have a noisy dehumidifier running in our basement, but even thought it's set to 50, I rarely get the humidity in the basement below about 60 something.

(We also only run the a/c when it's really unpleasantly hot out...)

A friend and long-time N-scale modeler did advise that I seal all my benchwork with polyurethane to help reduce warping, so I am doing that.

I also am wondering about biting the bullet and getting a new, more powerful dehumidifier, which would cost *a lot* more than a new loco... :(

But I haven't yet had the opportunity to see how all this affects actual trackwork...

Erik
 
blackz28 said:
honestly I don't know but when I lived in new Hampshire it had the same climate as you,& I had new house built & when I built a layout I also bought a dehumidifier , & ran it
24/7 spring summer & fall 1 because of the new concrete & the humidity from the season , but it worked for the 11 years I lived there ,of course down here they have no basements..... grrrrrrrrrrrrrrrrr but that's another rant lol
Click to expand...

Same here in California .. Double Grrrrrrrr
I can understand Florida, but not here?

Maybe if we had basements the autos would not have to be parked in the drive because the garages are full of stuff that should be in the basement.
 
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I live in New Orleans, where we see humidity in the 80%/90% range in the summer. My train room is pretty well insulated, right now it's staying in the 60% range. I am going to get some damprid for winter, as last year I did notice some condensation on the windows when it got really cold. Either that or I need to go out there more. Now that I am actually building that will probably be the case.
 
This is a great thread, a very smart question Greg!

I wish I had a great answer, but I'll share what I know.

Humidity should be kept at a minimum, what that is I do not know for sure. High humidity causes problems with corrosion, expansion, can play fits with electronics and numerous other problems.

I have my layout in my basement and I live in Baltimore. My basement is air-conditioned, but with outside humidity levels rising about 90% many times in the summer the best I can do is to keep my basement in the 50% range. I could do better, but I am always opening the door to let my silly beagles out. I love my puppies!

So far I have not experienced any problems, but my first layout has only been up since January. I know from my experience as an industrial mechanic humidity has cumulative effects that may not show up for months or even years in some cases.

Keep a close eye on inside and outside humidity. You can get digital hygrometers to measure humidity cheap these days. I had an old analog meter and it is worthless because it is old and the humidity got to it! Harbor Freight has a nice multi-meter that measures humidity, sound level, luminance, temperature, voltage and more! for $44.99 http://www.harborfreight.com/5-in-1-digital-multimeter-98674.html and if you look in the Sunday paper or sign up for their newsletter you can get coupons to save 20% or more. You can also find simple digital hygrometers at your local stores for less then $20

Save and reuse those silica gel packs that come with new items. They are great for things stored in boxes and any where you can stash them out of sight on a layout near a sensitive piece of equipment.

Bottom line is keep the humidity levels as low as you can with out spending a small fortune. Dehumidifiers are a good cost effective option.

For me over 60% would be too high for me to tolerate and I would have to add a dehumidifier. I may learn that is too high. It will never be 0% and we would not want it to be.

I have not read any specific recommendations concerning acceptable humidity levels. I am sure there is an expert on here that can tell us more.

Louis
 
I try to keep my basement around 50% humidity or less, and use two dehumidifiers as well as Air conditioning in the summer and heat in the winter. The most difficult time is in Spring and Fall when neither the heat or the AC is on that much. Then the humidity rises and the dehumidifiers tend to ice up, reducing their efficiency.

Joe
 
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