House Humidity With Woodstove.

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JA600L

Minister of Fire
Nov 30, 2013
1,288
Lancaster Pennsylvania
I'm sure this has been discussed. I just wanted to gain some clarity on the topic.
I have allergies, dry red irritated eyes, dry skin, and slight asthma. I've had it my whole life and it does not seem to stem from running the woodstove. I'm also an ag mechanic so there is no doubt I get some of my symptoms from that environment. For the most part my symptoms are mild.
My question is how can I make my home the most comfortable for these symptoms? With the stove running I manage to keep the hygrometer in my bedroom in the normal range. However, I do have dry skin and red dry eyes (mostly from my work environment).
Should I override the hygrometer in my room and add a humidifier? I would like my house to be a place of recovery for my body since I am around harsh environments all day. Thanks for any help.
 

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If I'm reading the numbers correctly the relative humidity is over 60%. At that level, I don't think I would benefit from more humidity.

This being said, I get the sense from reading discussions in other forums that the desirable humidity level for comfort is going to vary from person to person. I've seen wildly differing figures being given. What I do know is that the hygrometers I had around the house used to give me readings in the 45%-50% range. One week ago, I've bought a whole-house console humidifier and set it at 55%. This made a significant difference in my level of comfort. The one night it ran out of water, I knew right away when I woke up in the morning because I felt like I used to before we had the humidifier!
 
If I'm reading the numbers correctly the relative humidity is over 60%. At that level, I don't think I would benefit from more humidity.

This being said, I get the sense from reading discussions in other forums that the desirable humidity level for comfort is going to vary from person to person. I've seen wildly differing figures being given. What I do know is that the hygrometers I had around the house used to give me readings in the 45%-50% range. One week ago, I've bought a whole-house console humidifier and set it at 55%. This made a significant difference in my level of comfort. The one night it ran out of water, I knew right away when I woke up in the morning because I felt like I used to before we had the humidifier!


I'm not sure I trust that gauge. I went out and got a digital humidifier that gives you a relative humidity reading. It reads 33%. It sounds like I may have found my problem.
 
If I'm reading the numbers correctly the relative humidity is over 60%. At that level, I don't think I would benefit from more humidity.

This being said, I get the sense from reading discussions in other forums that the desirable humidity level for comfort is going to vary from person to person. I've seen wildly differing figures being given. What I do know is that the hygrometers I had around the house used to give me readings in the 45%-50% range. One week ago, I've bought a whole-house console humidifier and set it at 55%. This made a significant difference in my level of comfort. The one night it ran out of water, I knew right away when I woke up in the morning because I felt like I used to before we had the humidifier!


+2 on that. I bought two 2400sf consoles online on Amazon by Aircare brand and I use one on each house and it is a big different. I also have some weather station by Lacrosse that are more accurate than those hygrometer that you have. I have one of those at the house in town and never match the weather station and the console.

Can be possible you not getting an accurate reading out of that one.
 
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Be careful about going so humid that you get indoor mold problems. That won't be good for your asthma or the house.

While it might be worth testing for a couple nights to see if going more humid would help you, it looks like it's already very humid inside.

If more does help you, maybe you could compromise (run a humidifier right next to the bed all night, let the room dry out all day).
 
After a few minutes plugged in the relative humidity now dropped to 31% . My whole body feels extremely dry. I think even a 10% difference would make a huge improvement. I'll let it run for a while and see what happens.
 

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Fortunately our winters are pretty damp with relative humidity usually >85%. Currently the RH is at 95% outdoors and 54% inside. If I lived back east I would install a good humidifier or two to keep up the humidity. Here, if the humidity drops too low, I make beer :). A large steaming pot of wort cooking for over an hour works pretty well.
 
After a few minutes plugged in the relative humidity now dropped to 31% . My whole body feels extremely dry. I think even a 10% difference would make a huge improvement. I'll let it run for a while and see what happens.

That's very dry and not very close to the 65℅ that the other hygrometer was reading! :)

I personally keep a calibrated hygrometer so I can tell how far off my other ones are. (You can do a reasonable 75% setpoint calibration on them at home using a plastic bag and some table salt.). You can get a digital one on amazon for under $20.
 
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Working on air sealing helped my RH immensely. I haven't had to run a humidifier in 3 or 4 years. Humidity is replaced by cooking.
 
Working on air sealing helped my RH immensely. I haven't had to run a humidifier in 3 or 4 years. Humidity is replaced by cooking.

I've actually done a fair amount of air sealing to my house.
 
Keep working at it!


If the warm air doesn't leave, cool air isn't pulled in. Heating that cool air is what kills the humidity in a home!
 
agree with zeno up above, those are just relative numbers on that device and have very little accuracy. if you want a somewhat more accurate number - invest in one of the more expensive indoor/outdoor Lacrosse units.

Otherwise, if you are getting static shocks - it is too dry. If you are getting water on the inside of your windows, it is too moist.

Get a whole house as suggested above. https://www.essickair.com/humidifiers.html available at some big boxes, sears or online
 
For human health and comfort, a good working RH range is 30-50% at normal room temperature. For structural health of a house in a heating climate, winter time RH ought to be below 40%; letting it go to 50% or higher puts it at risk of mold formation. A house that is so dry that its occupants want to humidify is a house that leaks far too much outside air. That dry air is flushing out the humidity produced by human activity inside. So EBL is right: if your house is too dry inside in winter, the first thing to do is a serious air-leakage-sealing operation, perhaps by a professional using a blower door and IR camera to locate and seal all those myriad leaks. It's no big secret that new houses deliberately built to be very tight to nearly eliminate leakage-related heat losses need active ventilation, typically through a heat recovery ventilator (HRV), to keep interior humidity down to a level (30-40%) that works for both people and the structure. When you deliberately add humidity to raise the RH inside to something comfortable, you have to ask yourself where all that water is going. You really don't it want it to be passing through your walls to the outside, or the colder parts of the wall structure are going to wind up quite wet. If it doesn't dry out fast enough when temperature warms up to mold-formation levels, mold is what can happen.
 
I'm wondering if humidity is your only problem. Since your symptoms are long-standing, you probably have already looked into other solutions, but I may suggest a whole-house hepa filter system. It doesn't take much in the way of small allergens in the house to trigger reactions like yours.

Your occupational exposure may have sensitized you to some of these allergens.
 
i think the activity of cooking ,taking shower etc, help a lot to keep good humidity levels on modern houses. that is my experience in my house in town that it is 20 years old. we bought it new. At the ranch the situation is different but acceptable. I still working on little details to make it more tight.

now, in town still. when temp drop on 20s like for the last couple weeks or lower, beside of the indoors activities that create humidity, during the overnight it can get a little dry. humidity levels can drop high 20s to low 30s. I think it is normal. the air inside the house start losing temp and that make your stat turn on and your furnace kicks in, true?
I believe that start drying the inside air regardless how tight is the house, right?. i think a humidifier in this part of the country can be a good thing to have. Maybe i wrong but there is a point when nothing inside the house is creating humidity and the heating degrades more and more the existing RH?
 
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OK, the basics...


It all comes down to one tidbit. Warmer air has the ability to hold more moisture than colder air.


Outside is cold, say 33°F and raining. There is no way to put more moisture into the air.

Now inside, we want it slightly less miserable. Say 70°F. We heat the air inside to that temperature. Where does that warm air go? To the top of the room, where it leaked out ceiling fixtures, past window seals, etc. Your house is a chimney and creates a low pressure area in the house. To balance out that pressure, cold air is pulled in from outside. Now, that air is holding as much moisture as it can outside, but as it warms up, it'll want more, because it can hold more. Its going to get that moisture from your walls, hardwood floors, furniture, and even your skin. That's why you itch.

Air sealing the house works to keep the warm air in, so cold makeup air isn't needed. There will always be some air needed, but hopefully enough that cooking provides enough moisture to cover the needs.
 
The one thing I can't do much about is the duct work in my ceilings. I have sealed the ducts to my best ability and insulated on top of them. To some degree though it's just the way the house is. I could close the flaps in the vents but then I can't use the air handler at all.
 
Thanks for the answer and i have a question if you don't mind. the reason is cause i want to have a better understanding.
Lets say we have a room that it is 100% seal with 70df plus 70RH. Then when temp drops inside and we try to bring temp back to 70df, we run a furnace but the cold side is from inside of the room, NO OUTSIDE AIR AT ALL. are we keeping the same RH of 70 regardless?
 
Otherwise, if you are getting static shocks - it is too dry.

man i get so many shocks im afraid to touch my stove. I feel like Pavlov's dog or something. I have a big kettle of water on the stove but that doesnt seem to help much.
 
Thanks for the answer and i have a question if you don't mind. the reason is cause i want to have a better understanding.
Lets say we have a room that it is 100% seal with 70df plus 70RH. Then when temp drops inside and we try to bring temp back to 70df, we run a furnace but the cold side is from inside of the room, NO OUTSIDE AIR AT ALL. are we keeping the same RH of 70 regardless?

As the temp drops, the humidity will increase until it reaches the point where it cannot longer be held by the air and fallout of it. It may condence on the walls if they are cooler like an aluminum can.

Now, it may be splitting hairs, but I think of a furnace as forcing hot air into a room. But let's say you had baseboard heat. Then yes, if you brought it up to 70°F, the water would eventually be reabsorbed iinto the air.
 
In the winter, inside humidity has a direct correlation to cold dry air intrusion. Basically if your house isn't air tight the cold dry air will find away to come in and the air will dry out fast, the heated air coming from the stove is probably over power the cold air that's coming in so it seems warm and dry inside, moral of the story is to seal up your house, if your stove can have an OAK install one so the make up air is coming from the outside rather than the inside.
 
ten four. thank you for the answers. At the ranch i still working like mentioned before. i think it is almost close to be real efficient. after the house is up to temp the stove is keeping up with no problem on low keeping good inside temp and getting easy 20 to 24 hrs out of a load. two weeks ago I purchased a FLIR ONE thermal imagine camera and i was able to find some spots of air intrusion plus some areas on walls and attic, i jump quick and start working on those but i have more work to do.
 
I have read in many places making sure you are running fresh air to the wood stove is important for humidity control Cold air is usually dry air, and your wood stove will draw fresh air from somewhere, usually pulling that outside cold dry air into the house. So with fresh air to the stove it pulls that cold dry air into the stove not the house. Make logical sense, I have real problems with low humidity in the winter so I am putting in a fresh air to my wood stove.
 
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