Foo - Dehumidification of Basement in Winter

I recently bought a dehumidifier for our basement since the humidity was getting too high (I was starting to see rust on my tools). I was running it just enough to keep the relative humidity below around 60%. The unit is very nice except for one annoying problem: the humidistat is terribly inaccurate, and even with compensating with the settings as much as possible the unit runs far too much. So in addition to compensating with the settings I now run it with an external timer.

But now that winter is approaching, I wonder if I need to run it regularly. I have read that the same relative humidity is actually less humid in the colder parts of the year because the cold air can hold less water. So if I want to run the dehumidifer as little as possible (I'm big on conservation), what should I do? I haven't run it in over a week and the relative humidity has stayed under 60% according to the non-electronic meter I have downstairs. I would of course run it if we had a flood, but besides that what should I be doing? Should I just try to keep the relative humidity below say 65 or 70%, or do I not even need to worry about it outside of flooding, etc.? I live near the southern tip of Lake Michigan.

Many thanks for any words of wisdom.

Wish I had that problem. I have a central humidifier tied into my heating system to ADD humidity to the dry, heated air blowing around the house.

Not sure I"m supposed to, but I run it with the A/C in the summer too, since it's so dry up here.

I always used to run mine in the summer....never needed to in winter. Ymmv

I live in Texas, where basements are as common as snowballs, so I have nothing to add to this thread.

i'd like to add nothing as well.

I ran a cellar dehumidifier in our place in WV where it got to 10zillion% humidity in the summer. I had to set it to max to keep it going sufficiently, it was soooooooooooooooo very muggy. Anyway, in the winter, it just stopped running, and I was happy w/ that. Maybe yours isn't finely tuned enough to stay at 60% reliably but if it does go down more in the winter maybe it will be able to pick up on that.

ps-> the cellar dehumidifier made a huge difference in the whole house. We were getting big hairy mold growths out of the walls, on the stair bannisters, you name it. The cellar was very musty, and the dehumidifier cleared even that out. That plus putting plastic down over the dirt floor in the unfinished part.

Colder air holds less moisture. We have run a dehumidifier in summer, and a vaporizer in winter. To some extent it depends on what your source of heat is. We use oil, which makes the air even drier - as would gas heating.

I recall my parents had one that they ran year-around (Minnesota) I imagine your weather is similar, if not more humid?

Can you put it on a timer, so it will still run occasionally? Better spending a little cash on your dehumidifier energy than ending up with a musty and ick basement.

I live in Texas as well. Here because the bedrock is so close, not many home builders are willing to chip away the large amount of rock needed to have a basement. Only things that have basements are buildings for plumbing, HVAC, electrical, and other stuff.

Maybe yours isn't finely tuned enough to stay at 60% reliably but if it does go down more in the winter maybe it will be able to pick up on that.



Thanks, I hadn't thought of that. I'll try it out.

And thanks to everyone else for your replies. My house is about 5 years old and it has central air with a natural gas fired furnace. I close the vents in the basement in the winter but open them in the summer because when the A/C does run it helps with the dehumidification.

It seems to be clear that I don't need to worry much in the winter unless of course I had a flood. I'll just keep checking the meter whenever I go past it. We don't have a humidifier yet but we may get a small one for just the bedroom. The only considerable problem I seem to have with the drier air is that my hands get dry but I'm content with just rubbing some lotion in. My wife is much more sensitive to it though (perhaps because she's Puerto Rican?) And if we're considering adding water to the air, then removing water shouldn't be much of a concern!

Wish I had that problem. I have a central humidifier tied into my heating system to ADD humidity to the dry, heated air blowing around the house.

Not sure I"m supposed to, but I run it with the A/C in the summer too, since it's so dry up here.
I'd recommend against running the humidifier in the Summer. To an HVAC system, humidity acts a lot like heat. It takes more energy to cool humid air than dry air. And for Winter, warm humid air feels warmer than warm dry air, so increasing humidity in the Winter will allow you to run the heat less. So, adding humidity in the Winter is good, in Summer, bad.

I have 2 dehumidifiers in my basement...just shut one off yesterday. You shoul dhave gotten one that you can set the humidity level on rather than go no go. I set mine to 60% and if it runs it runs....if not it doesn't.

This is the end of my first full year in the house, but I run a dehumidifier in the basement all year (only really runs in the summer), and a humidifier on the main floor in the winter...

it depends

The fact that the house is heated in the winter drys up the air. You are spending way to much thought on this. The humidistat works better than you think. There's no reason it should be exactly the same as another humidity meter. The humidifier is automatic, set it lower if you think it runs too much. It will run less in winter all by itself. Evey house is different, leave it on all the time. If the cellar gets dry in the winter you'll find out in the winter. Then it will not run itself if it's set where you like it, you don't need to do anything. Most people don't need to run the thing in the winter, you will find out soon. But unplugging it is the same as it not running when the air is dry. Except you might have water in the drip pan, that could get moldy.

Gas or oil makes no difference at all. There's many other factors. Running the dehumidifier makes all that stuff unimportant anyway. It runs or it doesn't, period.

You shoul dhave gotten one that you can set the humidity level on rather than go no go.

I do.

http://www.heatcontroller.com/series.php?prod=ca&sid=44&c=30

But as I said the humidistat is terribly innaccurate. I knew that it was innaccurate based on the Consumer Reports review, but I thought I would be able to compensate with the settings. Turns out that it was even more innaccurate than I expected. It's a shame because everything else about, besides being made in China, is great. I considered returning it but decided that keeping it and using it with an external timer would be best.

I'd recommend against running the humidifier in the Summer. To an HVAC system, humidity acts a lot like heat. It takes more energy to cool humid air than dry air. And for Winter, warm humid air feels warmer than warm dry air, so increasing humidity in the Winter will allow you to run the heat less. So, adding humidity in the Winter is good, in Summer, bad.

Do you know much less heat is required when using a humidifier - just a little or are we talking big time? If I'm concerned primarily with saving energy, would I save by using a humidifier in the winter? Would a small ceramic electric heater run less the same an HVAC system would if using a humidifier? Thanks!

The humidifier is automatic, set it lower if you think it runs too much.

That's what I was hoping for, but as I said, I set it as low as possible and use the built-in timer and it still runs far too much. I didn't expect it to be exactly the same, but I compared it with two other meters and it wasn't even close to either. I don't want it running more than is required. I agree that I am thinking about it more than I should have to, but if the humidistat were better this wouldn't be an issue.

I did find that my vents were still open in the basement though, so now that they are closed the humidity may rise. We'll see.

Do you know much less heat is required when using a humidifier - just a little or are we talking big time? If I'm concerned primarily with saving energy, would I save by using a humidifier in the winter? Would a small ceramic electric heater run less the same an HVAC system would if using a humidifier? Thanks!

Sorry, I don't have any numbers. And even if there were an expert who did, he'd likely need to know more info, like your current heating requirements, energy costs, etc. However, there are more considerations than just energy costs. Dry air will also result in dry skin, dry air passages in your throat & lungs, and numerous things in your house (like furniture) doesn't like extremely dry air. How much do they dislike it? I don't know. I don't have a humidifier, but I want to get one. One thing I do now is to NOT run the bathroom exhaust fan during showers. I run the HVAC fan to distribute the moisture evenly through the house. If you're REALLY interested in lowering energy costs and increasing humidity, you could dry your clothes on an indoor clothesline. No energy to run the dryer, and free humidity to boot.

I used to get nose bleeds in the winter from the lack of humidity caused by furnaces. I think a dehumidifier instead of AC is the way to go in the summer, and a vaporizer maybe in the winter. Although around here, heating, cooling and humidity levels haven't been much of an issue for me.

Dehumidifiers loses effectiveness in when it's cold because dehumidifiers work by cooling the air to condense the water vapor to water. Check your owner's manual for the operating temperatures.