HI, Thank you in advance for your contribution, can we say that it is actually necessary to humidify the air by burning wood? I understand that absolute humidity does not change, only relative humidity changes. I have a hygrometer, but I think it's Chinese, and at any temperature it oscillates between 49 and 51 percent, I do not trust him. Based on your experiences, Does it depend on the case or is a humidifier almost always good?
wood stove and humidification
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I find that a humidifier is absolutely essential at my house. Some say, houses with air leaks require more humidification. Perhaps that’s why I need it. Otherwise, everybody will have a dry scratchy throat. We have a freestanding unit. If you’re asking about a humidifier in your ductwork, I think that is a little bit more controversial Because some people say that there’s health concerns and it could also ruin your ductwork.
EbS-P
Minister of Fire
@LogCabinFever
Thanks for your report, yes, as other members are confirming, if the stove sucks air from the inside, and the house sucks from outside, air enters,
very dry,
and therefore tea pot does its part!
@EbS-P
Thank you very much, I'm not sure about the reliability of my hygrometer, at 50 percent, it seems low to me, I have dry throat and also dry eyes At 55-60 everything seems normal.
Thanks for your report, yes, as other members are confirming, if the stove sucks air from the inside, and the house sucks from outside, air enters,
very dry,
and therefore tea pot does its part!
@EbS-P
Thank you very much, I'm not sure about the reliability of my hygrometer, at 50 percent, it seems low to me, I have dry throat and also dry eyes At 55-60 everything seems normal.
A very tiny part unless that tea pot is very large or the room is small, especially when the outside air is hovering around 20% humidity. A good humidifier can go through a gallon of water a day and not keep the space above 45% humidity.
Dry air in the winter is really caused by air leaks in your house. Let's say if your humidifier goes through 3 gallons of water a day, that's how much moisture is being drawn out of your house every day via air leakage. Yes, the stove contributes to the air leakage a little by consuming some air, but in many houses, especially older ones, the overall air leakage is much higher than what the stove is pulling. If you have a particularly tight house, you'll know right away because the stove's draft will be negatively affected by it.
If you don't have a humidity problem in winter, it either means your house is pretty tight, or your outdoor conditions are damp/warm enough that the fresh air coming in isn't very dry.
Tightening up the air leaks is the best thing you can do to increase humidity. Keep in mind that "outward" leaks on the upper floors are just as important to fix as the "cold drafts" but are much more difficult to locate.
If you don't have a humidity problem in winter, it either means your house is pretty tight, or your outdoor conditions are damp/warm enough that the fresh air coming in isn't very dry.
Tightening up the air leaks is the best thing you can do to increase humidity. Keep in mind that "outward" leaks on the upper floors are just as important to fix as the "cold drafts" but are much more difficult to locate.
The most intuitive scale for absolute humidity is the dew point. Dew point tells you at what temperature the humidity will be 100%. Dew points of 40-55F are ideal for comfort.
Edit: however, for indoor conditions, I would posit that relative humidity is more useful. Even if you have large temperature swings, and the relative humidity changes inversely with those temperature swings, it's still the real time RH% that affects things like dry skin, static electricity etc.
For outdoor conditions, I'm still a major proponent of tracking the dew point instead of RH.
Edit: however, for indoor conditions, I would posit that relative humidity is more useful. Even if you have large temperature swings, and the relative humidity changes inversely with those temperature swings, it's still the real time RH% that affects things like dry skin, static electricity etc.
For outdoor conditions, I'm still a major proponent of tracking the dew point instead of RH.
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Ashful
Minister of Fire
First, without an OAK, you are actually changing absolute humidity. This is because the absolute humidity in your house is affected by human activity, namely cooking and hot showers, but also perspiration, produce sitting on your counter, etc. Without an OAK, your stove is drawing all of that humidified air out, and replacing it with outside air. Then the act of heating this fresh outside air pushes its relative humidity even lower.
Those with an OAK, and IIRC you fall in this class, are the only ones who do not really impact absolute humidity. In your case, you're not drawing a lot of make-up air into the house for the sake of combustion (unless you have other burning appliances, eg. oil furnace), and you are indeed only affecting relative (not absolute) humidity.
There are plenty who would disagree with this. I'm in the RH% camp for anything other than outside weather.
Agreed, for outdoor.
What is an example of a more intuitive scale for absolute humidity?
We have a wood stove but do not use it for heating our home. We have to run a humidifier in the winter to keep the humidity comfortable. We try to keep it between 40-45%. We actually run 2 portable humidifiers. Our home is a log cabin so it is not a tight house.
The portable units that we have can be set to a desired humidity level so they will keep running until that set number is reached. We prefer the portable units because they can be cleaned.
The portable units that we have can be set to a desired humidity level so they will keep running until that set number is reached. We prefer the portable units because they can be cleaned.
Yes, lots of people suffer with low humidity in the winter and it's not just people with wood stoves.
Ashful
Minister of Fire
When discussing human comfort, whether in the home or outdoors, absolute humidity is mostly irrelevant. This is why relative humidity % is the measure most use, for everything from humidifiers to dehumidifiers.
When talking about outdoor weather, where temperature may swing 20F - 30F from morning to evening, playing havoc with any quoted constant RH%, dew point becomes more useful.
Absolute humidity is only of use or interest to engineers and scientists, not the general population.
St. Coemgen
Feeling the Heat
It depends on the case.
Personally, our small stone house retains enough moisture from cooking, washing and breathing that winter humidity is never an issue. The ovens keep humidity at a good level.
But it becomes a significant issue in the summer, as the house is too humid from cooking, washing and breathing, and we have to vent the house. Stone is impermeable to moisture.
Side note: Even a cheap hygrometer will give you an accurate reading. An exact reading? No. But a good enough reading. If you do not trust it, buy one or two more of different quality and price and compare them. They most likely will be similar. I have two. They give similar readings. Both mine are duel -- thermometer and hygrometer combos to allow one to compare relative humidity.
Hope this helps.
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I wholeheartedly disagree. I can be comfortable at a wide range of humidities, but the temperature is what determines my comfort at a given relative humidity. The result is that the range of dew points (absolute humidity) at which I feel comfortable is pretty narrow.
Ashful
Minister of Fire
That's fine! But when you say "temperature is what determines my comfort at a given relative humidity," you're acknowledging that both play a part in comfort.
Also note that we're talking only about indoor humidity levels, in a conditioned space, during wood burning season. Your assertion would be more valid if we were talking about outdoor humidity in July, in that case I'd agree that dew point is the most useful measure, but that's not the discussion we're having here. No one uses dew point to discuss indoor humidity during heating season,
So true, I have a forced air furnace, when that is running my humidity is much lower than when the wood stove is heating the house.
St. Coemgen
Feeling the Heat
I can.
We had a heck of an issue with dew point in our house in the winter for a long time, despite "normal" hygrometer reading. In the corners. Near the floors. They were cold enough to cause dew points. Caused all sorts of issues, including black mold. Our solution was to never put anything into the corners to allow air flow. That seems to work. But makes furniture decorating a bit "interesting".
And still our double insulated glazed windows still get a lot of condensation on them in the bedroom. Have yet any solution to that other than taking a towel each morning and removing the condensation. A dew point issue. The glass is still cold enough to cause condensation from our night time respiration which increases total local air moisture to cause a local dew point issue.
And let us not forget all the people now saying heat pumps increase humidity... no they do not... but their installation in old houses, that are then sealed and buttoned up to increase heat retention** but they also end up keeping normal human activity moisture in the house, are having dew point issues with black mold etc. on walls that are not insulated to account for this change .
** Such houses need a trickle vent at least, but... you know.... government grants ignore professional advice that know better. And everyone gets their money... and everyone is happy till it does not work that way. Because, of course it would not work that way.
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Thank you all, really.
I just want to motivate because, in my opinion, absolute humidity would be better, if with a humidifier I put 55 percent, at 20 C and then with the stove I reach 25 C that 55 percent at 25 degrees it contains much more water, if in the night I return to 20C RH will rise to around 65 without humidifying I mean. But it's not right, because if I'm looking for ideal RH increasing temperature, ideal RH is lower, I would venture to say that according to what I read, the ideal humidity, it is an absolute value and not a relative one, for example ideal at 20 C degrees, I read between 40 and 70 at 22 C degrees between 40 and 60. Relative humidity is more for scientists in my opinion, maybe because they found an easier way to measure RH instead of absolute. Dew point, it's interesting because it is proportional to absolute humidity. And if we consider absolute humidity, it is also better to avoid condensation in corners, avoiding fluctuations of humidifiers.
I would say that the solution is precisely a dew meter, establish an ideal point, and turn on the humidifier only when necessary!
I just want to motivate because, in my opinion, absolute humidity would be better, if with a humidifier I put 55 percent, at 20 C and then with the stove I reach 25 C that 55 percent at 25 degrees it contains much more water, if in the night I return to 20C RH will rise to around 65 without humidifying I mean. But it's not right, because if I'm looking for ideal RH increasing temperature, ideal RH is lower, I would venture to say that according to what I read, the ideal humidity, it is an absolute value and not a relative one, for example ideal at 20 C degrees, I read between 40 and 70 at 22 C degrees between 40 and 60. Relative humidity is more for scientists in my opinion, maybe because they found an easier way to measure RH instead of absolute. Dew point, it's interesting because it is proportional to absolute humidity. And if we consider absolute humidity, it is also better to avoid condensation in corners, avoiding fluctuations of humidifiers.
I would say that the solution is precisely a dew meter, establish an ideal point, and turn on the humidifier only when necessary!
Ashful
Minister of Fire
My humidifiers all self-regulate, set an RH% and they maintain it within roughly 2%. But as you note, it does not account for a tightly-sealed space with changing temperature, where RH% could vary a lot against a constant AH%.
With two stoves and one boiler drawing air from the house, and tending to keep the house at a relatively constant temperature (courtesy of Blaze King), this hasn't ever been an issue for us!
With two stoves and one boiler drawing air from the house, and tending to keep the house at a relatively constant temperature (courtesy of Blaze King), this hasn't ever been an issue for us!
You missed my point. Sorry if I wasn't clear. Dew point is a single number that can tell me whether I will be comfortable or not (within a given range, of course). Whereas you need both temperature and relative humidity to determine the same thing!
Dieselhead
Minister of Fire
I have a 13 hear old house, it’s pretty tight. Even had a blower door test done on it when it was new as part of a power company study on new construction. My house performed great. My stove has a o.a.k. All that being said if I don’t run a console style humidifier the RH in my house will be in the low 20s and everyone including the dog is getting static shocks and dry noses. So I’m not 100% sold on “wood stoves pull in dry outside air”.
Is there a fresh air exchange system like an HRV or fresh air feed into ducting in the house that regularly brings in outside air?
Dieselhead
Minister of Fire
No.
Funny enough, I believe the least restrictive path of fresh air into the house is actually the wood stove. In the summer time, when the weather is right and we turn on a bathroom fan or range hood I can get a creosote smell in the house wafting towards the exhaust fan from the stove. Turn off the fan and the smell dissipates. I’ve read others have that issue too.
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