Ventilation Reverse Draft Issue: Cold Air Blowing into Bathroom & Missing Rotating Attachments

Hello.

I have been living here for 3 years (3-story block without basement / underground parking), ground floor but somehow I have never felt it before.

Since the temperatures in the bathroom are very negative, you can feel the cold air clearly.
When you put your hand on the ventilation grille, you can feel that the air is blowing into the bathroom. In the second room, a room with a kitchenette, I have 2 ventilation grilles and everything is ok here - the air is drawn out.
Only in the bathroom is there a problem with the air blown.
Opening any window causes draft in that grille and air is drawn into the chimney.

So far I covered the ventilation hole in 2/3 and I'm going to report the problem to the administration.

As I noticed, there are no rotating attachments on the chimneys. I think their assembly would solve the problem ... but is it?

This is normal behavior with tight windows.

What do you propose to unseal the windows?
Why, then, in the second room the ventilation works as it should, i.e. it draws in air?

I have additional external blinds installed and I close them in the afternoon because I noticed that thanks to this it is much warmer in the apartment. This, in combination with tight windows, can result in additional sealing ...

As I write, I have never felt this phenomenon to such an extent that I have to do anything about it.

Well, and mounting the swivel cowl on the chimney will not solve the problem?

Added after 3 [hours] 48 [minutes]:

I was recommended to install a window diffuser.

zlotaraczka. wrote:

What do you propose to unseal the windows?
Why, then, in the second room the ventilation works as it should, i.e. it draws in air?

It must be blowing somewhere so that it can blow somewhere.

I have additional external blinds installed and I close them in the afternoon because I noticed that thanks to this it is much warmer in the apartment. This, in combination with tight windows, can result in additional sealing ...

As I write, I have never felt this phenomenon to such an extent that I have to do anything about it.

Well, and mounting the swivel cowl on the chimney will not solve the problem?

Yes, but on all risers

Added after 3 [hours] 48 [minutes]:
I was recommended to install a window diffuser.

One person from work has air vents.
He says that in the summer it is cool, but in winter it is not so much because it blows with cold air.

And what is it supposed to blow, warm?
Close all the grilles and you will have a paradise, a stench, dampness and fungus.

How are you going to handle it like this, you'd better not do it at all.

I advise as I see fit. In this syt I decided that this is exactly the advice you need to understand what you are "messing with" and encourage you to be interested in "how it works".
Everyone knows that he blows with cold air, and this is the smallest problem with heating. This is why diffusers are mounted in the windows, and heaters under the windows, so that you do not feel the cold.

What solution do you propose for the bathroom to also extract air and not blow it?
I conclude that my ventilation is working properly due to the fact that I described at the beginning?
Even a slight unsealing of the window causes a draft in the grate towards the chimney.

Today, when the wind changed direction and it is a bit warmer outside, the bathroom is warm, despite the fact that the thermostatic head is set to the same position as yesterday and the radiator is cold.

As for my windows and the location of the radiators.
I do not have windows as windows, only balcony doors as an exit from the apartment to the garden. The same in the next room. Except that there are two independent balcony doors that act as an exit to the second garden.
The radiators in both rooms are placed perpendicularly on the walls to the exit doors to the gardens.

zlotaraczka. wrote:

What solution do you propose for the bathroom to also extract air and not blow it?

You have already received the answer: you should install diffusers in the windows (balcony doors). Depending on the weather conditions, you will open or close them so that each of the ventilation grids in the house extracts air. The air must have some circulation: it flows in through the diffusers, it flows out through grilles.

In each room there should be an air vent with an appropriate capacity proportional to the number of people, or for example two smaller ones. The air inlet must ensure the supply of fresh air at least 20-25 m3 / h per one person at a negative pressure of 10 Pa. In the annex, as there is a hood, it should have a non-return flap valve that cuts off the air flow when the hood is turned off. If there is no eaves, it is one block too many there. The grilles can be replaced with adjustable ones to be able to control the process more, those with a greater thrust are more closed, and those with a smaller thrust - vice versa. Buy an inexpensive hygrometer and control the humidity from time to time by adjusting the diffusers and aiming for the range of 45-55%.

Problem solved.
The additional gaskets stuck on in one of the windows and improper adjustment of the pressure of the frame to the frame were to blame, probably in the times of the previous owner of the apartment.
I removed the unnecessary seals, leaving the original ones, and adjusted the window as it should be.
There is no back draft in the bathroom.

Unfortunately, yesterday I noticed that in the kitchenette there is a reverse thrust from one of the grilles - I have 2 next to me. On the one hand, it blows air into the apartment depending on the direction and strength of the wind, and the other grille always draws air from the apartment and directs it to the chimney.

As for the reverse draft in the bathroom, it is currently not present because a rotating chimney cowl has been mounted on the chimney. However, on the chimney connected by channels with the kitchenette, there is no such attachment.

I wrote a message to the administrator of the estate about such a problem and am currently waiting for a reply.
If, however, the installation of such an extension were to take place, perhaps, in the spring, I would be inclined to cover the channel from which it flows into the apartment with something. However, I wonder what the effect of such a covering could be. Will there be, for example, moisture from the side of the canal? Currently, when the wind blows from the wrong direction, the air is blown into the apartment. Changing the direction of the wind or its weakening results in the fact that both grilles exhaust air from the apartment to the chimney.

A very slight unsealing of any window causes a draft in the chimney.
I checked several times and even removing the gasket at the top of the apartment entrance door from the cage causes draft in all grilles and blowing air from the apartment into the chimney.

Install the check valves on the grilles. They have the form of a rigid foil on a plastic frame. For example, in Castorama they are probably an accessory for fans. I have one at home and it works fine. It costs a few zlotys. But from what I can see it will not be necessary, because you have a problem with the lack of air supply.

A slight unsealing of the window is necessary for the ventilation to work. There is supposed to be a string. This is how gravity ventilation works.

All I need to do is remove the door seal above the entrance door from the cage to the apartment and the thrust returns ...
Again, the reverse thrust itself does not occur all the time, and from what I noticed it depends mainly on the direction but also the strength of the wind ...

Reverse thrust is due to the lack of air vents. Remove the gasket and let the gravity ventilation work or install recuperation.

zlotaraczka. wrote:

A very slight unsealing of any window causes a draft in the chimney.

I suspect a colleague gas water heater (with a candle) in the bathroom and this candle causes (forces) flow (draft) in the flue gas duct of the heater. This thrust automatically creates a negative pressure in the room, which causes a reversal (if there is no other way of air inflow) of circulation in the bathroom ventilation duct. Certainly, the inflow of air through the ventilation grille intensifies when the flame in the junkers ignites.
This

zlotaraczka. wrote:

All I need to do is remove the door seal above the entrance door from the cage to the apartment and the string returns ...

is a clear proof of this. Air must flow in some way to replace the one that went into the chimney.
The use of a cap on the bathroom extractor eliminated the backflow there, but it caused it in the kitchen. Like electricity, air flows along the paths of the least resistance.
The parents-in-law, when there were junkers with a candle, was similar. Now, when it is without a candle, there is a backflow in the ventilation grate only when the gas in the junkers ignites.
There would be no back-up if the junkers had a closed combustion chamber.

I don't have a junker or any other such device.
I will try to figure out the seal because as I wrote. A slight unsealing is enough, no matter which window or door, and the draft is great everywhere.
I was taking the gasket off one day and everything with ventilation was ok. However, I felt that there was air movement in the apartment and it was getting cooler from the cage which is not heated despite the block from 2009. Heating is gas from a stove in a boiler room. One kiln per block.
I must admit that due to the perceptible movement of air in the apartment, I was afraid of heating bills because I like heat. A radiator with the thermostatic head unscrewed to 3. The temperature in the rooms is around 22.5 to 23 degrees and the humidity in the rooms is within the range of 47 to 50c/o, i.e. approx.
With these grilles in the annex, I will add that there are 2 next to each other and when it blows from one, it pulls out the other.

zlotaraczka. wrote:

With these grilles in the annex, I will add that there are 2 next to each other and when it blows from one, it pulls out the other.

If both are open and operate "in parallel", you can cover one of them with a colorless tape and then the bare one will only pull out - so it will be better. Fresh air should be supplied from vents or window slits.

I had an idea to stick one grate, but I was starting to wonder what would happen then on the other side of the tape if such a channel was not used ... whether something unwanted, such as dust or other rubbish, would start to accumulate there, although I think that the main channel in the chimney runs from from the bottom to the top and the flats in the staircase are connected successively to this channel.

If it blows, the ventilation is too high. Adjust the length of the removed gasket so that it does not blow and there is ventilation at the same time. For example, a CO2 concentration meter and a hygrometer will be helpful. > 1000 ppm CO2 or humidity> 65% increase ventilation.

I solved this problem by inserting check valves in the ventilation.
The cost of the valve is about PLN 12 plus a piece of pipe and grille.
I get the air supply when cooking and the hood is on (which has an exhaust outside the building) by unsealing the window.

Cold air is heavier than warm air - that's physics.

If you close everything in the house, so that cold air does not blow through windows, doors and other leaks, the cold air will enter the apartment through the ventilation ducts under its own weight. So there will be a circulation between the ventilation ducts, whether you like it or not. One ventilation channel will let cold air flow in, and the other will go up warm and humid and that's it.
In the absence of wind and some spinning on the roof, this mechanism will work non-stop in winter, because that's physics.

If you close the ventilation ducts completely, contrary to appearances, you will not keep the heat in the house anyway, because there is another mechanism at work. The point is, you'll get your apartment wet. I don't even write about moisture in the kitchen or bathroom anymore. Moisture is related simply to human life, breathing itself is an emission of moisture.
You will not have efficient ventilation, this moisture will accumulate in the furniture, fabrics, etc. The more moisture in the apartment, the more energy you need to have a higher temperature in it, because the moisture will steal this heat to turn into water vapor. This phenomenon is visible in winter on window panes in airtight apartments. Water runs down the windows and makes puddles on the windowsills.

Contrary to appearances, you can hurt yourself by sealing everything. If you do not care about your own health, you will also hurt your own pocket, because heating will also cost more. During the first winter season, newly built houses absorb a lot of heat because they are damp and dry, without ventilation you keep your apartment moist all the time.

If someone is unconvinced to what I wrote, it is enough to get an air dryer, i.e. a mini heat pump. After activating this miracle in a damp room, the temperature will go up by itself as the humidity drops.

I described both mechanisms because in winter they often connect with each other, because people quite naively think that if they tighten everything up, they will save it.

And here you are right mate idepopizze .

There was no one in the apartment since Friday.
Before leaving, I set the thermostatic heads to the 2.5 position, because you know nights with frosts, and during the day also not too warm. Today, after returning to the apartment, the temperature inside is 20.5 degrees and the humidity is 29 degrees. It gently blows from one grille and the other grate next to it pulls out quite strongly.

I am also trying to figure out the door seal, and additionally I have asked the administrator of the estate to install a swivel cowl on the chimney. I am to have an answer tomorrow the day after tomorrow.
So, I'm waiting.

29% is quite dry, as it gets colder it will be even worse. If you have a hygrometer, the problem is rather excessive ventilation. Install hygroscopic grids or with manual regulation and limit the air flow in both drafts, so that the humidity stabilizes in the range of 45-55%.
I also think that the installed chimney cowl is unnecessary and even harmful in this system.

Today it is around 40c/o humidity.
Such a low level was caused by the absence of the household members.

After a few days, when the wind had different strength and the outside temperature was different, I noticed that in the kitchenette, an exposed grille draws air into the chimney, and a half-covered grille in the bathroom, where a swivel attachment is installed at the end of the ventilation duct, the air is also drawn to the chimney. chimney.
Air humidity in the apartment varies from 30 to 40 percent.
In the bathroom, after a bath, it will rise to 71 percent for a while, then it drops and after about 5 hours in the bathroom with the door closed, there is 42 percent humidity. Similarly in the kitchenette. After cooking it is around 55 percent, after a few hours it fluctuates around 40 percent.
I am talking about the situation where the windows are not tilted.
Their unsealing causes a rapid decrease in humidity through air exchange.
That is, limiting the air flow through the grille in the bathroom where there was a strong draft, would stabilize the ventilation in both grilles, because there is no back draft in any of the grates.

Probably the best solution to the problem would be this type of device. I don't have one myself yet, but I'm going to buy one. Maybe someone has and could share opinions. According to the manufacturer, such a device will provide good ventilation without blowing cold air.

AWENTA COMPACT RECUPERATOR HRV100







The HRV100 compact recuperator is equipped with an accumulative heat exchanger, the task of which is to retain and accumulate thermal energy in the process of air exhaust from the room in which the system is installed.

The accumulated heat is successively transferred to the air supplied from outside. Thanks to this solution, it is possible to distribute fresh air at a temperature that does not differ from the temperature in the room - regardless of the weather conditions outside.

The system works in two modes: exhaust and supply. Each of the modes can operate in two speeds:
1 - slow exhaust - slow supply
2 - quick exhaust - quick supply.

The gear change is carried out by means of a pull chain located at the fan body.

The duration of each of them is 60 seconds.
The heat exchanger is made of aluminum.

The device has a significant advantage over other competition solutions due to the following aspects:
o Innovative design of the heat accumulator made of aluminum
o Reduced energy consumption of the fan to the level of 1.5 W in the first gear
o Simple wall installation without ducts
o Possible heat recovery if only one room is ventilated
o Quiet, energy-saving fan
o The standard equipment includes a supply air filter

Finally, I purchased and installed check valves for the ventilation ducts in the annex. A dozen or so zlotys art. The perfect diameter, because fi 120, as well as the ventilation duct behind the grate. Push-in installation and grille in place. Without any modifications.
It has been working since that winter. There is no backtracking.

But such plastic valves from the OBI supermarket or some metal ones? Are the plastic ones sufficient?