A "breathing" frame house

[buldozer]

- It’s too early to strike. In a wooden house a humidity is the same. Unfortunately, in the Russian internet you can only catch these quotes: "The fact that the relative humidity in a wooden house is 45-57%, i.e. the moisture content as close to optimal for a human habitation - 40-60%. And defined by the humidity in a wooden house is supported by all the time, and does not depend on the weather changes likely related to advertising. a research on this topic does not come across. In English, too, there is nothing, it seems there are small buildings made of wood. But since my interests are not limited to construction themes, I can bring as the evidence the fact that in wooden houses plants feel incomparably better. In particular, the lemons in winter have a bad feeling in concrete houses (sadly, looking at mine) and do well - in the wood.
A request. Who has a wooden house look at a humidity.
In frame houses full of such effect can be achieved except when filling the frame with a straw. But at least you can try it. In particular, filling the frame by an ecowool or a sawdust. But the accumulation of moisture, of course, is possible only to a certain limit. The timber is somewhere around 18%. So, I’m interested in the question, how exactly is the gradient of moisture in the wall, which has a conductivity of the capillary (in my case, this is a cardboard), under different conditions.
1. With a limited water vapor permeability equal to the inner and outer skin.
2. With a slight excess (3-5 times), the water vapor permeability of the outer wall.
3. With a little temporary excess of water vapor permeability of internal walls. (The ice in the outer casing, or a very high humidity outside).
So, far it is known that at a high vapor permeability and equal to both skins. A "warm" edge of the gradient is too low to influence such as the humidity inside the room.
As for a filtration and a sorption of harmful substances.
Stay in ecowool can only be what it is irreversibly adsorbed. But on the indoor climate in which case any effect would not be (unless it is a radioactive isotope).
A concrete, a brick, a foam, etc. at least absorb all sorts of rubbish than a cellulose, and probably more.

[bill]

Please, if this is still true. Only once a reservation - the device is not laboratory, but a commercial souvenir - a thermometer and a hygrometer.
So, the old log house (1938), the wood is in excellent condition, but a caulking (a tow), and an insulation in the ceiling ( a slag or something like that) are not ideal. A frame extension with a conventional insulation (all slots), which is a gas boiler. Wood windows with a double glazing, the internal contour sealed for the winter with a sticky tape. A permanent residence.
It is August now, the temperature in the house is up to 22 ... 24 +, the vents are open. A humidity is up 90%. With the heat on the street - up to 100%.
As the cooling humidity starts to fall, for the New Year will be up to 50-60%, further more - reached 40% and below. Dried up the skin and lips, tickled in the throat, pimples appeared on the hands, sparks in the dark.

[expert]

If the temperature is -15 or below, it is required to swich on a humidifier almost constantly to get 50%, when you feel better or normally, and no sparks from the cats. The humidifier has a large tank and there is the automatic for the humidity and the exhaustion of water. However, the testimony of my automation and the instrument differ by 10%, but this can be adapted.
Why not just get up to 40%, but only after the New Year?. The only reasonable explanation is a house and a furnishing that give the moisture gradually accumulated over the summer and the autumn.
No frosts are in the house except that the outer glass is frosted over, when it is absolutely cold (for Moscow, of course - not for Siberia). A conclusion all the steam goes through the boiler (and during the frosts, probably, through the pipe inflow).

[baltazar]

You forgot one more point – an effectively removing of harmful contaminants entering the premises from the building materials, a furniture, etc. After all, the hygiene certificates "for the indoor use" are granted based on the normalized atandard norms. One air exchange per hour, or 3 cubic meters per 1 square meter. If there is no suh air change, then you can take on the certificates for the ecowool, even if they are "fake."
An illustrative example. Many coatings require an application outdoors or in a well-ventilated area (so, they are harmless), or a respiratory protection (because they are harmful in a closed room). Or there is another example: the most environmentally friendly engine according to Euro-4 (5,6, ...) is deadly in a closed garage. So, they are "harmless" and "green" only under certain conditions, and the air exchange is the most important of them.
Therefore, by the way, do not really quite "off" a ventilation in the house when there is no one, you will have to return there, and a dirty trick has already accumulated in the air. Or, just to air – swich on a kitchen hood, in bathrooms and open all the windows.
So, "breathing" walls can effectively remove the contaminants, as in this case, the entire volume of air in the room moves from the inner surfaces of walls to the place of extraction (a boiler, a gap under the door into the hallway, etc.) And the air flow is observed only from the point of inflow (a supply valve, a ventilator, etc.) to the place of hood. Of course, this does not happen in a straight line, and the flow is quite wide, but still remain stagnant zones, which would accumulate harmful substances.
Of course, this is only a schematic model. However, for a clarity: try to vacuuming the floor without attachments, like a brush, with only one tube. The air flow is the same but the performance is lower.
This was quite popular, but with formulas and diagrams, the author of technology TISE, R. Yakovlev writes about the scheme of displacement a ventilation and mixing. You can have different attitudes to the technology itself, but in this part of his mind is difficult.
Returning to the list of benefits of "breathing" walls: a heat recovery during the infiltration through the walls does not occur - the wall hasn‘t simply a heat. Therefore, the removal hazards from frame houses is more effective, as well as a carbon dioxide and a steam, regardless of the location of sources. The only major advantage of "breathing" walls. But how!.

[Summer]

It may seem that there is a fly in the ointment, the air passes through the wall "pie", taking out all the harmful substances that it will find, and a vapor barrier do not protect us from them. This way, the question of what the walls would accumulate harmful things as a filter, but they will give them back.
However, for materials that are certified for the indoor use, it does not matter because the conditions of safe use provided as a sufficiently effective ventilation. And the rate of release of contaminants at low temperatures is reduced (from a school chemistry, the increasing of temperature by 10 degrees increases the reaction rate by a half, and vice versa).
There is one more caveat. And what does it happen during the summer when the boiler is turned off, and a natural ventilation is not effective?. But in this case and there is no usually infiltration through the walls: there is no outflow and no pressure difference inside and outside. The aeration occurs through the open windows, bypassing the walls. Although, of course, the hazards are removed poorly, and not in vain bourgeois parasites try to always put the forced extraction. We are, incidentally, also no one bothers. There are drawing fans in the kitchen, and often in bathrooms. But while the infiltration is not still there (after all, windows are open), so, you shouldn’t care about materials of the log house.
And the last one. To simulate the "breathing" walls can be in the presence of a vapor barrier - just on the walls, opposite to the ducts, it is necessary to lay ducts distributed the inflow. And a happiness comes.

[buldozer]

The flow of CO2, water vapor, water and other things, going out, hangs "joules” on the walls.
A counter flow of oxygen and water are joules, if possible, collects. The required for this exchange heat of walls must be at least the same order as that of the media. That is, very negligible.

[expert]

CO2 is generally very difficult to dislodge from the room air exchange, since this gas is very heavy, heavier than the air it is a factor of 1.5 - 2. Because the best exhaust for the gas ae stoves due to the low-lying hood, and breathable walls are the best to optimize a humidity.

[buldozer]

If everything is done correctly, it can not be limited to a thickness of log house. That is, to increase the water vapor permeability of house with a male part with respect to the internal, to apply a heater, a high-quality (three-layer) wind-super-diffused moisture protection and a good ventfence. The ventfence plays a crucial role in te ventilation of facade, it is a great stretch of a water vapor from the heater and thus prevents the accumulation of a condensed moisture in it.

[bill]

Suppose, we have a wall of a thickness h = 0,2 m with a thermal resistance R = 4,0 W / m * degree and a vapor permeability n = 0,03 mg / m * h * Pa (like a foam). Then, when the temperature difference t = 40 ° (sorry) with each square meter of wall each second: P = t / (h s R) = 40 / (0.2 * 4) = 50 J.
And how much does go with "hampfull substances"? First, calculate the mass of "these substances". Suppose the pressure difference is a great figure like 1000 Pa. Then, using the same square. meter of wall, every second it will be:
m = n * p/h/3600 = 0,03 * 1000/0, 2/3600 = 0.042 milligrams!.
Even assuming the specific heat of these sustances equal to the heat capacity of water (one of the specific heat substances) q = 4,2 J / g * deg., we find that the substances every second bring from our square meter:
Q = q * m = 4,2 * 0,000042 = 0,18 mil (!) Joules.
So, about the heat, portable by these substances, you can easily forget. But I was curious, but how much heat you can still recover? .Suppose we have a room 4 * 5 m with two external walls. For a single air exchange per hour we will get that through a square meter of wall with a flow only through the infiltration should be held V = 4 * 5 / (4 +5) = 2.2 m3 / h
At the air density of 29 kg/m3 we have a mass m = 29 * 2.2 = 64 kg / h, which corresponds to 0.018 kg / s.
Thus, through each square meter of wall 18 grams of air per second must take place. Rounding the specific heat of air up to 1000 J / kg, we find that for the heating of air we need
P = 0,018 * 1000 = 18 J.
That is, with a flow only through the infiltration, we could at the expense of heating the air in the wall to count back 18 of 50 joules per square meters with walls - 36%. So, great!.
It's a pity that this can not be, because there can never be - a wall may miss only 0.042 mg / s, and with the inappropriate pressure difference Pa 1000. To understand what it is – for a standard door 2 * 0.8 m will be affected by the force F = 2 * 0.8 * 1000 = 1600 N, i.e. approximately 160 kg. Even with the run it will not open!
After these calculations it is time to take back my words about "the efficient removal of impurities in breathing "walls." All the infiltration does not constitute 1/100% of the required air. And what a efficiency!. Sundry, please check the calculations. Or I just have long been bred for "breathing walls" as a stupid, and I kept repeating like a parrot?. And all this may be true only for the log cabins with a caulking and nothing else?.

[Summer]

This is a reflection, or where they were taken from?.
In fact, there are, for example, wells, filled with a methane.The person got there and he disappeared. But about CO2 I have not heard that, it drifted. No, it certainly tends, as more heavy. But there is also the phenomenon of Brownian motion, diffusion and the effect of partial pressure. If they were not, we would collect an oxygen under the ceiling.

[constructor]

At work, again, I serve the heating and water ducts. That's before going down into the well, first, a lamp of the gas analyzer with a burning flame (like a kerosene)is descended. Now, if there is a big methane concentration in the well, then the flame grows stronger, but if there is a great concentration of CO2, the flame dies. From my personal experience, the flame always goes out at the very bottom of the well, if the CO2 concentration is very high, sometimes it will be higher.

[expert]

I think that the example with the well is incorrect. In the house, such a situation cannot be created.
In the well there is a strong source of a heavy gas. And this gas is simply no time to dissolve and mix with the air, although there is a mixing, but it is rarely compared with the new arrival.
It may be a similar case, if the tank with the hot water from the bottom is mixed with the cold water.
The water will not is mixed.

[bill]

The room has also a source with the release of a heavy gas, it is a human life being i.e its breath. During the night you can breathe a lot and then wake up with a "square" head.
The water (if I remember correctly), the density is the same at all temperatures, in your example will be only the heat. But if the fuel adds in the water, the water will almost instantly lunge into the sediment. But why? A human, too, has considerable "opportunities." Where to find only one magazine, which gives the average figures for the human "exhaust"? I didn’t throw it, just I do not remember exactly where to look for. And there is a lot of filth, a foam and a plywood.

[expert]

You are wrong.
Have you ever seen how the water moves in the pan even when it is not boiling? The movement is called a convection.
How do you think, at the expense of what?
I am not arguing here about the well. (It is unclear just how a CO2 gets in to the well, unlike a CH4.)
And you do not argue! One case in a practice. A stoker fall asleep and a half of tank accumulated with the hot water and a half of tank with the cold water. Then he merged the cold and warmed further.
A person can breathe and I do not argue. And a head will pop. But the composition will be homogeneous in this case. Or rather homogeneous. I assume that the percentage of oxygen at the top will more.

[buldozer]

I am not an expert in this field, but I will express on this occasion my thoughts. You can deny me, I will not be offended.
That is, the water expands when heated? When it is freezing, yes, but when heated ... I do not know, I will not argue. I think that when the water is heated, the heated air rises in the form of bubbles which create the water movement.
The convection (as I understand) is the cycling of things (the principle of the water cycle). That is, such as a heated air from the heaters because of its lower density relative to the cold rises in the upper room and when it cools down there, it goes down, and so on, that's such a cycle is obtained.
Is there such a thing as a thermocline (I know it from the fishing books). The essence of thermocline, is when the upper layers of reservoir are heated by the sun, and the bottom remains cold. It happens when you feel that cold in the water depth in a lake. But, here the lower layers of water can’t warm by the icy ground water (springs) and the temperature is too low as a solar energy. Here, in the rivers there is no thermocline, because the water flow is mixed and there is a heat exchange. On the quiet streams the water on a coastal zone can warm stronger than on a fairway. Of course, everything within reason, because in areas where there is ventilation, a CO2 stretches. The question is how efficiently it is! You can breathe all your life by a stale and a dusty air, it's not fatal, but it influences the quality of life (a health).

[expert]

You really have never heard that a climate of wooden houses is very different from other houses, wrapped in a polyethylene, in particular. It differs by the air humidity, which is in a wooden house is higher due to the lack of a vapor barrier.

[buldozer]

You wanna say that a wooden house in winter drains the moisture from the street? In summer, there is no problem with the lack of moisture in any home. In winter, the cold air outdoors, heated indoors loses a relative humidity,
humidifiers. And that, the wooden walls have a source of extra moisture? Which they have accumulated during the summer? Or some other?

[expert]

I guess that in an ordinary house a vapor just goes into the ventilation, but instead of it enters the dry air from the street.
In the wooden house there is another process. The vapor penetrates into the wood, it condenses the moisture, and then moves on to the concentration gradient. Partially, goes outside and partially goes back. Other source of the air humidification is not visible.
The wall, roughly speaking, is the vessel of water. And this water is evaporated.

[constructor]

Please, explain me an idea. It is not clear, how the moisture can move in the environment with a temperature gradient in two opposite directions? By the way, perhaps, I thought, but in this discussion, some members have not decided exactly where the issue is moving the moisture - indoors or outdoors. It's two different things!
The "breathable" wall of a frame house has a single, very specific function: to bring out the moisture out, such as a ventilated façade or a vented roof through a permeable membrane and do not let it inside. That’s all. But the aim of a ventilation system to provide a comfortable humidity indoors.
The room should not be vented through the wall, and the ventilation system should not dry walls.

[expert]

So, what you have written, was a standard approach to solving complex problems: first, to try to break into elementary components, which are solved separately and then slap it all together.
In our life processes linked more strongly, and a vapor barrier not only solves one problem but it creates much more.
The idea of the "breathing house” not to go against the flow, but to use physics processes and material properties for integrated solutions to create a comfortable home for a human habitation. And a ventilation is definitely needed.