Correct ventilation in the bath: the main points. Ventilation in the washing section of the bath Wooden box with foil for ventilation of the bath

Ventilation is needed in all rooms, the rules for its installation are spelled out in SNiP 41-01-2003. But they concern only residential, public and industrial premises, in which conditions favorable for a person are created. At the same time, it is taken into account that people stay in such rooms for a long period of time and for everyone it is necessary to create the same standard indicators of microclimate and air quality.

Baths have completely different tasks, they create a stressful microclimate for the body - high temperatures (in Russian baths up to + 60 ° C, in saunas more than + 100 ° C) and high humidity (up to 90%). Moreover, in one room, the temperature and humidity indicators should vary within wide limits, depending on the wishes of the washable. Changes in microclimate parameters should be made as soon as possible, and the achieved values should be maintained for a relatively long period of time. And another very important difference between the baths and ordinary rooms. If, secondly, people have the opportunity to "protect themselves" from temporary inconveniences by clothing, then in the baths it is impossible to do this.

Steam room microclimate illustration - high temperature and hot steam

Based on these features, the ventilation of the baths must fulfill individual tasks, and this affects the principles of its design and the peculiarities of its functioning. Ventilation in the bath can be natural and forced, each type has its own characteristics, characteristics, advantages and disadvantages. In this article, we will talk in detail about only one type of ventilation - natural.

We have already found out the tasks of ventilation of the bath and how it differs from the ventilation of other rooms, now it is time to tell in what ways they can be achieved. The methods depend on the architectural features of the room and your preferences.

First you need to remember the physics lessons from school. Ventilation of premises occurs due to the difference in air density outside and indoors. Heated air has less weight and rises up, cold air is heavier and falls down, so-called convection occurs. Accordingly, in order for the room to be ventilated, hot air must be able to leave, and cold air must come in and out. These can be ordinary cracks in windows and doors or specially made ventilation holes.

On the Internet you can find statements that these holes must necessarily have the same dimensions, otherwise the ventilation does not work or "blows in the wrong direction." Only those who skipped lessons can say this. The ratio of the sizes of the inlet and outlet of air does not affect the performance of ventilation in any way.

Square ventilation window

If the outlet, for example, can release only 1 m3 of warm air per hour, then exactly the same amount will enter the cold room, whatever the size of the inlet, and vice versa. And the effect of reverse thrust is obtained in the case of wind back pressure or in the complete absence of fresh air supply. In the first case, a strong external wind "drives" the air into the room, in the second case, after the air is released in the room, a small vacuum is formed, which draws the air back into the room. This is not to say that ventilation is completely absent, it just becomes cyclical and works on the "back and forth" principle. Of course, the efficiency of such ventilation approaches zero, the air moves a little only near the holes.

And with these phenomena it is clear, now we will consider specific types of natural ventilation in the bath. Let's start with the simplest ones and end up with the more complex ones.

The simplest, but also the least effective method of ventilation.

In the steam room, a door opens or a door and a window open at the same time - ventilation occurs quickly, but not in the way we would like. Why?

Steam is removed from the bath, and this also has negative consequences.

Firstly, if you open the door, then the steam does not go out into the street, but into other rooms. Humidity rises sharply in them, heated steam immediately condenses on all surfaces. There is no need to explain what may happen next.
Secondly. Lowering the temperature in the steam room is only a subjective phenomenon. There are two concepts of temperature - actual and perceived. The actual temperature is a physical indicator, the perceived one is subjective. We feel the same actual temperature differently depending on the surrounding factors. High humidity "raises" the temperature we feel, strong wind lowers it. So, due to simple ventilation, only excess steam can be removed, and the actual air temperature returns to its previous values within a few minutes.
Thirdly, ventilation will never be able to establish stable indicators of the indoor climate. As soon as the doors are closed, the temperature and humidity rises sharply, as soon as the doors are opened, the humidity and temperature also drop sharply.

The bottom line is that ventilation is not a ventilation method that should be used all the time. This is an extreme method, it is recommended to resort to it only in case of an urgent need.

This method can be considered more successful, but it is possible only in one case - the firebox of the sauna stove is located in the steam room. Warm air is removed through the firebox and chimney; it can be supplied through the floor slots, a slightly open window or door. Sometimes a special hole is made in the lower part of the door leaf; to improve the design, it is closed with a decorative grill.

The advantages of ventilating a bath with a stove.

Simplicity of execution. There is no need to make special vents in the log house. Any additional hole in a wooden wall does not improve its performance, to put it mildly. If mistakes were made during the period of blowing and installing decorative grilles, then the risks of moisture getting on the crowns of the log house increase. The moisture will dry out for a very long time, and the prolonged stay of wooden structures in a wet state has an extremely negative effect on their strength and durability of use.
Possibility to regulate the frequency of air exchange in the room. Ventilation is "controlled" by a gate and stove doors. It is necessary to speed it up - the gate and the firebox door open all the way, the temperature has become favorable - the gate closes a little. You can easily find the optimal position of the gate, the microclimate indicators in the steam room are stabilized, the ventilation rate of the room has stable values.
Gate stove - photo
Versatility of application. It does not matter what materials the bathhouse is built from, what size and architectural features it has. In addition, this system allows easy upgrades. For example, it is worth making an inlet behind the stove and the air entering the bath will be slightly warmed up. The chimney still serves as the hood.

There are, of course, disadvantages, let's name the main ones.

Insufficient performance. You cannot quickly change the temperature or humidity in the steam room.
The presence of "dead" zones. Air mixing throughout the entire volume does not occur, there are areas with drafts and areas with standing air.
Dependence of draft (ventilation) on weather conditions.

Despite some disadvantages, this method of ventilation in combination with ordinary ventilation is very often used in "budget" versions of baths.

For a budget steam room, the best option is oven ventilation and airing

Airing the bath with a stove - diagram

The best ventilation device for most baths.

Advantages:

Important. It is advisable to think over the ventilation device even before starting the construction of the bath. Solve issues with specific hole placement and dimensions. We advise you to make the height of the air vents no more than the height of the timber, and adjust the flattening of the holes with the length.

Bath fan prices

bath fan

Why is it better to provide ventilation during the construction phase?

Firstly, it is much more difficult to make holes in an already finished structure, purely physically.
Drilling a hole in a log house is a laborious process
Secondly, there are risks that the hole will fall on the dowel, especially for the upper outlet duct. It is located in close proximity to the rafter system's Mauerlat, and they are fixed more often than ordinary crowns and only metal rods or pieces of construction reinforcement are used as dowels.
Thirdly, if you make a hole with a metal crown, then an expensive tool will fail after "meeting" the dowel. And the chisel or chisel will not always be possible to "reanimate" after attempts to cut through the metal.
Fourthly, the metal dowel in this place is almost impossible to cut off. You can't get close with a grinder, a hacksaw for metal as well, and you won't want an enemy to cut with a file. We'll have to hammer the air in another place. And who needs an extra hole in the wall of the bath or an increase in its size? Moreover, if you have already made holes in the outer and inner lining for its "planned" dimensions and bought ventilation grilles. A "meeting" with a metal nail is a very unpleasant situation from all points of view.

Variants of placement and sizes of ventilation ducts

There are some general rules for all types of natural ventilation. First, in order to improve the efficiency of the system, the cold air supply holes should be located at the bottom of about 20 centimeters from the floor level. Exit openings should be located at the maximum height - under the ceiling or on the ceiling. Second, the mixing of various layers of air in the volume of the steam room is improved if the inlet and outlet openings are located at the maximum distance from each other, preferably along the diagonal of the room. Where are they recommended to be installed?

It can be done at the bottom of the door leaf of the steam room.

Advantages - there is no need to make an extra hole in the wall of the bath. This saves time and effort, in addition, the likelihood of the lower rims of the log house getting wet is excluded. Disadvantage - in most cases, the doors are located opposite the shelves for taking bath procedures, cold air flows appear, creating a number of inconveniences.

Under the shelf.

Advantages - the inlet is invisible, cold air flows well with warm air throughout the volume. Disadvantage - access to the lattice for opening / closing the damper becomes more difficult. If during washing it is possible to adjust the ventilation intensity only with the help of the upper grill, then after airing the baths, both must be closed. And this means that after a while you will have to visit the steam room especially to close the air.

Important. Dampers on the ventilation openings must be installed two each - outside and inside the steam room. After airing the baths, both should be closed. Choose a grille installation technology that guarantees complete tightness of the external dampers. It is strictly forbidden to get atmospheric moisture on the crowns of the log house.

Behind the stove.

Inlet behind the stove - diagram

The most optimal option. Cold air from the street will hit the stove, warmed up a little and break into several separate and low-speed streams. Drafts are completely eliminated. Disadvantages - it is not always possible to install decorative grilles in this place. If the stove is close to the wall, the high temperature will negatively affect the plastic or wood materials of the decorative grill. In addition, according to safety regulations, such places behind the stove must be insulated with sheet metal using thermal insulation.

Not a single option for your particular case? No problem, make a hole wherever you want.

As for the outlet, there are fewer problems with its placement. Our only advice is don't do it in the ceiling. Waterlogged air should not be taken out to the attic, it will cause constant moisture in the wooden elements of the truss system, and its premature repair always costs a pretty penny. To protect the rafters, moist air will have to be removed to the roof. Why make an additional hole in the coating, why do it yourself and for your own money worsen the tightness of the roof covering?

Sizes of openings for natural ventilation

The technology for calculating the size of the ventilation openings is specified in the current regulations. Determining the size of air vents for natural ventilation is much more difficult than for forced ventilation - there are too many factors beyond the control of people. The main parameter of the ventilation system performance is the frequency of air changes. For residential premises, the minimum value of the multiplicity is regulated, while taking into account both the temperature in the rooms and the temperature outside. The temperature in the living quarters fluctuates within insignificant limits, this simplifies the work of designers.

In steam rooms, the situation is much more complicated - the temperature and humidity indicators vary over a very wide range. In addition, the speed of air intake / intake in different situations may differ significantly. These preconditions make it nearly impossible to accurately calculate the optimum air exchange rate for natural ventilation.

Some bath owners are afraid of suffocation during bath procedures due to lack of oxygen. We bring to their attention that one cubic meter of air is enough for one person to breathe for an hour and a half. Calculate the cubic capacity of the steam room and find out how long you can safely bathe, the count goes for tens of hours.

Carbon monoxide can cause problems. If you closed the stove gate before the wood is completely burned out, then no amount of ventilation will help. She can ventilate the room only if no more carbon monoxide is supplied. Heat the stove correctly and never get burned, do not rely in vain for ventilation.

How to make a ventilation hole in the wall of a bath

For example, we will take the most difficult option - the external and internal cladding of the walls of the bath has already been done. The hole can be round, square, or rectangular.

Step 1. Make a marking of the location of the vent on the inner lining of the steam room. Before starting work, you should not only know the location of the hole, but also its dimensions and configuration. It is desirable that air ducts and decorative grilles are available, this will make it possible to accurately control the size of the hole and not do unnecessary work.

Step 2. Prepare a long drill for wood, the working length should exceed the thickness of the bath wall together with the outer and inner cladding. In the center of the drawn vent contour, drill a through hole from the inside of the steam room. The drill exit from the outside of the steam room will be the center of airflow. Draw around it the dimensions of the hole, similar to that made in the steam room.

Step 3. Remove the internal and external cladding in the contour. If your bath is lined with natural clapboard on both sides, then the process is simplified, just carefully cut the boards. If metal sheets were used on the outside, use a grinder.

Step 4. Carefully inspect the supporting structures of the cladding, if they are damaged, repair it. Drill through holes along the contour of the ventilation duct as close to each other as possible, constantly check where they come out from the outside of the wall. The drill must be perpendicular to the plane at all times. Drill the same holes over the entire area of the air vent, the more there are, the easier it is to make a hole in the wall.

Video - How to drill a large diameter hole in wood

Step 5... Next, you need to work with a chisel and a chisel, gradually remove the wooden bridges between the holes. It will not be possible to completely poke a hole on one side of the wall - it is too difficult to reach with a tool. Do half of the work from the inside of the steam room and the other half from the outside. It is not necessary to carefully align the surfaces of the holes, the main thing is that the air duct can easily fit into the channel.

The most difficult physical work has been done, you can start installing the air duct and grilles. Do not be discouraged if it takes a long time to make holes, even experienced builders can rarely prepare more than two holes per day.

How to install air ducts and grilles

For air ducts, you can take galvanized metal or plastic pipes, the length is determined by the length of the passage. Select the grille according to the size of the hole; to adjust the ventilation efficiency, it must have dampers.

Duct prices

duct

Step 1... Insulate the holes with mineral wool, carefully insert the air duct into place. In order to firmly fix the pipe in the desired position, use polyurethane foam. The excess foam that has emerged should be cut off after hardening.

Step 2. If there is waterproofing between the sheathing and the wall, foam the gap between the wall and the opening in the sheathing with foam, it seals the cut and prevents water from entering the wooden structures.

Step 3. Fasten the gratings, the method of fastening depends on the material of manufacture of the wall cladding and lathing.

We fix the ventilation grilles. In the photo - the lattice on the outside of the bath

Mineral wool prices

mineral wool

Check that the ventilation is working with a smoldering head or other source of smoke. Bring it to the inlet and observe how and at what speed the air flows in the steam room.

In the photo, the air intake valve and its performance check

Experiment with natural ventilation at various damper positions, from maximum to minimum.

Video - Installing the KPV 125 valve

Video - Ventilation in a bath with an air-conditioning oven Termofor

There is already a large review material on our website, so now it is worth talking separately about the cooker hood in the bath: how it works, how it works and how to make it yourself.

Hood in the bath: depending on which bath

Baths are built from a variety of materials, each of which has its own specifics. This also affects ventilation systems, which have their own characteristics in each case. We will talk about their differences in terms of organization below.

Sauna extractor hood

A sauna or a Finnish bath differs from a Russian one in a small amount of steam (this is practically a dry bath) and a high temperature (which can reach 130 degrees!). During your stay in the sauna, there is a clear rule regarding ventilation: the air must be changed at least 6-8 times per hour. This requires good air flow control, replacing the exhaust air with fresh air less than every 10 minutes.

Ideal for a sauna, (convection type). Let us briefly repeat that it operates according to the principle of an "inverted glass":

ventilation duct standing diagonally from the stove, takes in near-field air;
takes it out through the roof (wall);
below, next to the stove, there is an inlet through which fresh air comes in;
the stove heats up the oxygen-rich air, it rises and spreads through the sauna.

Flow regulation is carried out using dampers that regulate the openness of the duct and inlet. An important point in this case is the constant operation of the furnace, because it is she who performs the function of a "pump".

And even if the hood in the sauna is done according to a different scheme, the task will remain the same:

driven frequent air exchange;
good warming up arriving fresh air;
inadmissibility fast air currents (more than 0.3 m / s), i.e. drafts.

In the bathhouse from the log house

The log house was invented long before the laws of physics, on which natural ventilation is based, took shape. Nevertheless, the builders of log baths actively used these laws so that the owners of the bath did not suffocate while steaming, and the bath stood for decades. (Of course, the hood in the bathhouse from the log house will not save it from fire, but from rot - it may well.) In the frame, the air flow was ensured by the lower rims, which were deliberately laid loosely, that is, they had slots through which fresh air was "pulled". In addition, the door to the steam room below did not fit snugly to the floor.

Depending on how exactly the bathhouse was heated from the log house - "in black" or "in white" - it also depended on where the exhaust air went.

In a heated "black" bathhouse, the stove does not work during the steaming process, so an open window or door was used for the outflow.
In a heated "white" bath, the outflow was made through the chimney. The stove was working at the same time.

In principle, nothing prevents the organization of ventilation of the log house in the traditional way today. But the decision must be made promptly, even at the construction stage. Because a more modern solution should be incorporated into the project. Alternatively, you can punch holes (supply and exhaust) directly to the street and provide them with plugs or dampers. One is next to the oven blower, the second is above the upper shelf on the adjacent or opposite side. Or make two exhaust holes, one above and one below the top shelf. Another option is to make blinds at the bottom of the steam room door, and an exhaust hole under the ceiling of the shower room.

IMPORTANT! If you don't want to go outside, you can lay air ducts, but then instead of natural you will have to install a forced ventilation system.

In a foam block bath

A foam block bath is no exception to the rule that you need to think about ventilation when designing a bath. It's easier than punching ready-made walls. In order to provide a cellular concrete bath with sufficient air circulation, which will relieve the structure of excess moisture, it is necessary to lay pipe cuttings at the time of pouring the foundation formwork, which will then become airflows.

For a bathhouse, which is not in a lowland and is not surrounded on all sides by buildings, two ducts on opposite sides are enough, otherwise they are made 4. Do not forget about the ventilation gaps between the walls and the insulation.

The roof must also be ventilated, receiving inflow from the roof overhangs and giving air through the raised ridge. In the premises, supply and exhaust openings are made according to one of the standard schemes.

In case of insufficient natural ventilation, it is recommended to install fans on the hood from the foam block bath.

Sauna hood: in which compartment?

If we leave aside the questions about ventilation of walls, foundations and roofs already discussed in other articles, there are rooms - a steam room, a washing room, a dressing room and a rest room - where you need to organize air circulation. At the same time, there are certain standards regarding ventilation in each of them and the specifics of manufacturing the hood. But first things first.

Steam room hood

For those who are soaring, the hood in the steam room of the bath is a guarantee that they will come out of there safe and sound.

IMPORTANT! You cannot leave the steam room without ventilation openings at all, this is a big risk of getting dark or losing consciousness and suffocating with carbon dioxide. You cannot make only one hole.- this is how ventilation does not work.

The way to ventilate the steam room can be natural (due to the laws of physics) or forced (due to fans). The holes can lead outside, into air ducts and into adjacent rooms. Either blinds or dampers are installed on the ventilation openings. The air supply can be organized through the bottom of the steam room door, which is 3 cm from the floor, or with louvers at the bottom of the door leaf.

You only have to make a box with your own hands. Everything else (corrugation, valves, gate valves, dampers) is on sale. Fans (if needed) vary in diameter and power. A relay can be used to automatically control forced ventilation. The holes in the wall were either left behind during construction, or are punched through in an already built bathhouse.

Useful video

See how the craftsmen made a box for ventilation hoods from the boards:

In the washing room

According to the already mentioned standards, the air circulation in the washing room per hour should be a multiple of 8 volumes of the room for supply ventilation and 9 for exhaust. It means:

that the dimensions of the exhaust hole will be more inflow;
or the fume hoods will be two for one supply;
or delivered to the hood fan.

In any case, this is an intensive air exchange, which is primarily intended for quick drying of the washing room. It is not required during the washing process, therefore it is regulated by flaps.

By the way, inlets can be made in a dressing room or a rest room, and exhaust outlets in a washing room. This will allow you to ventilate two rooms at once. Similarly, the hood is done in the bathroom, moreover, it is forced to create low pressure. Then the air will be drawn from adjacent rooms and leave through the forced exhaust. Thus, the rooms are connected with through holes, which on the one hand will be supply air, and on the other - extract air.

The components of the hood in the washing bath do not differ from those used in the steam room.

How to make a hood in a bath

This has been said more than once, and yet it is worth repeating: the cost of arranging ventilation will grow many times over if done late, after the completion of construction. At the same time, the principle of creating ventilation in the bath remains unchanged: it is necessary to create conditions for the inflow and outflow of air from the premises. So, how to make a cooker hood in a bath with your own hands or with the hands of professionals.

Hood in the bath: scheme

There are many schemes, but one is suitable for understanding the principle of ventilation. Most often, ventilation schemes for the steam room are offered, but the scheme for the entire bath, with explanations, is of much greater interest.

Take a look at the sketch. It shows that ventilation is carried out in the washing room, steam room and rest room. Moreover, the flow of air is carried out from one pipe to two points, one of which is in the steam room, and the second in the rest room. The hood is located in the washing room, in the steam room, and in the relaxation room. We will describe all ventilation devices in each room:

Washing room- a window made of metal-plastic, an adjustable hood that draws in air through a diffuser located on the ceiling. From there, the air goes through a pipe to the roof.
Steam room- insulated window, located below the shelf, adjustable hood, which is a vertical box, the intake opening of which is 150 cm² below the shelf, and the exit from the chimney to the street is near the ceiling. One of the regulated inflow channels near the stove, cross-sectional area 150 cm².
Restroom- adjustable hood, which is a box with a cross-section of 150 cm², the height of the intake opening is 30-40 cm from the floor, exit through a pipe to the street near the ceiling. Regulated inflow through the second channel with an outlet near the stove firebox.

With your own hands: how to do it right

Do-it-yourself hood in a bath is not something that cannot be done, but you need to approach the matter prudently and slowly. In order to make your own hood, you need to prepare materials according to it. It is also necessary to calculate the cross-section of the ventilation pipes.

IMPORTANT! The inflow volume must be equal to or less than the exhaust volume.

To do this, you need to know the volume of the room and the multiplicity factor (how many times the air must be updated per hour) - it is in the standards. In main air ducts, the speed of movement should not exceed 5 m / s, in branches - 3 m / s, in a steam room - 2 m / s, natural ventilation - up to 1 m / s. Further, in the table, we find the value of the pipe cross-section, which is the closest to give the required volume at a given speed.

Knowing the cross-section, it remains to prepare a corrugation or pipes of the appropriate diameter, which are attached with one end in the room at the required height according to the diagram, and with the other they go outside. Self-tapping screws, metal tape and foam are used for fastening. The openings are supplied with dampers in the room, grilles at the outlet. By the way, ventilation should be cleaned once a year..

Useful video

Watch a small video, which clearly shows ventilation in one bath:

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Well, now you know exactly how to properly make a hood in the bath in order to save yourself, household members and guests from suffocation in the bath. It remains only to correctly apply the information received.

In contact with

During the construction of a steam room, a serious question arises: "How to make a hood in the bath?", Because we are dealing with furnace equipment, carbon monoxide, high humidity and steam. Ventilation in such rooms is needed no less than sewerage or heating.

In this material, we will tell you about the features of the device and installation of ventilation systems for the bath.

Bath ventilation

Appointment

As you know, in the process of life, a person converts oxygen into carbon dioxide. Fire does the same, except that in addition to carbon dioxide, carbon monoxide is also emitted. In the bathhouse there is both a man and a fire.

In addition, in the steam room and other rooms, there is an increased content of water vapor in the air. Such a combination of factors in the absence of ventilation will make it simply impossible to be in the room in half an hour.

Moreover, being in it will not only be physically unpleasant, but also dangerous, because carbon monoxide is odorless and can be poisoned unnoticed.

Important!
Hence follows the first and main function of the ventilation system: the supply of fresh, oxygen-enriched air and the removal of the "waste" gas with all harmful and dangerous impurities.
In other words, the hood ensures normal gas exchange between the room and the environment.

The next important point is the constant high humidity of the room. With insufficient air circulation in the rooms, water vapor condenses on the walls, water does not evaporate for a long time and begins to be absorbed into the building structure, in our case - into the tree from which the walls, floor and ceiling are built. Wood is wet and chemical corrosion occurs.

Attention!
For the timely removal of excess steam and ensuring the normal timely evaporation of condensate, the bath simply needs ventilation. A building with a poor, ineffective ventilation system will not stand for long, since the effects of moisture will be destructive.

That is, we see that an effective exhaust into the bath must solve at least two main tasks:

Fresh air supply and exhaust gas discharge to;
Drying of premises during and after procedures, maintaining normal air humidity.

Varieties

First of all, the classification of any ventilation systems begins with their division into the following classes:

Natural ventilation carried out through weakly ventilated, but large in area enclosing structures... In other words, gas exchange takes place through walls with high permeability, as well as through natural crevices, gaps and openings present in the building.
Such a system can be sufficient for small rooms with normal environmental conditions, as well as for small baths, together with the possibility of a sharp air supply through open windows, vents and doors.;
Natural convection ventilation, which is carried out through holes located in special places due to the difference in temperature and pressure, creating a convection air flow through the room... One of the most common schemes, since it does not require energy consumption and, with the right device, is quite effective. Well suited for small and medium-sized saunas, but insufficient for large and public spaces;
Forced, or mechanical ventilation, which is provided by forced supply or exhaust, or forced supply and exhaust at the same time... Also, often all supply and exhaust openings are combined with air ducts into a single system, and powerful channel fans provide the circulation of air flows in it.
Such systems allow not only to effectively ensure the inflow and outflow of air, but also to control the mode of its circulation, which is especially important for large and public premises and steam rooms..

The first variety was used in small-sized old Russian baths. The construction of the walls and ceiling, which consisted entirely of wood, made it possible not to worry about the air flow during the procedures, and after them all windows, vents and doors were opened and the room was dried.

If during the bath time there was a lack of fresh air, it was always possible to open the windows and doors and ventilate the room.

Convection ventilation works according to the following principle: hot air accumulates under the ceiling, the pressure of which is approximately equal to or higher than atmospheric. At the surface of the floor there are masses of cooled air, and the pressure of the column of heated gas above it is lower than the pressure of the column of atmospheric air.

If you open a hole at the bottom of the room, then a stream of air will rush through it, since the pressure outside is higher. As a result, the heated air in the upper layers will be compressed even more, and if we open the valve on the hole at the top of the wall, then the masses of hot exhaust air will begin to come out.

If you open both holes at the same time, a constant convection flow will arise, which will tend to equalize the pressure inside the room and outside.

The third type of ventilation system, or forced circulation, is relevant for large rooms and rooms with a large flow of people. Fans are installed on both supply and exhaust openings.

Such a system allows you to create the necessary gas exchange in almost any room, but it requires competent calculation, design and installation, and its price is sometimes too high for the consumer.

Since our article is intended for owners of individual baths, we will consider natural convection-type ventilation. This system is easy to set up with your own hands, and the instructions are simple enough to follow.

Installation of convection ventilation in a bath

Before making an extractor hood in a bathhouse for individual use, they think over their ventilation system. The inlets can be positioned in the plinth in the form of underfloor vents.

Then holes are made in the floor in opposite corners of the room, and the area with reduced pressure located near the floor surface sucks in air from the street, at the same time ventilating the underground space, which is very important for building structures of the floor and walls.

Important!
Even if you are not going to place the inlet in the basement, then you are still obliged to ensure the circulation of gas in the underground space, otherwise you are threatened with rotting of the lower rims of the bath and floor structures.

Let's represent the process in the form of step-by-step instructions:

Behind the stove, at a height of 40-50 cm from the floor, a hole is made in the wall with an area of at least 30 square centimeters, which is closed with a grate. On the inside, it is good to have a door or a plug that will allow you to close this hole if necessary (for example, when the room is too cooled down);

On the opposite wall, a hole is made under the ceiling, which is equipped with a grate and a latch on the inside to be able to adjust the air flow;

The area of the exhaust hole should be twice the area of the supply hole, since the viscosity of hot air is higher than that of cold air;
If in it, in order to direct the flow of air from the rooms where people rest to the toilet, and not vice versa;

It is also advised to place one hood in the washing room, and for baths with medium and large sizes, toilet and washing hoods can be equipped with fans, which are guaranteed to create traction and direct flows in the right direction;

It is not recommended to make an exhaust hole directly above the shelves, as a steamed person will be in a draft, which can cause colds, especially in winter;

The exhaust opening from the outside is extended with a pipe, which should raise it above the roof. This will provide more traction and therefore more efficient ventilation.

Important!
True signs of improperly constructed ventilation will be an unpleasant musty smell, an abundance of condensation on the walls, traces of mold and mildew, constant high humidity in the bath, even long after the fire.

Output

Ventilation is the most important system for a comfortable and efficient sauna. The extreme temperature and humidity conditions of the steam room and other bath rooms require a constant supply of fresh air, which can be provided by simple convection ventilation, the installation of which we have considered.

The video in this article will be a good help for novice installers.

In the process of arranging a bath, special attention should be paid to the issue of organizing high-quality ventilation. Without proper air exchange, the steam room will simply be impossible to use normally. If desired, all work on the installation of the necessary systems can be done by hand. It is enough just to understand the procedure for laying and connecting the main units and do everything in accordance with the instructions.

Bath ventilation is very important. To avoid protracted and not very interesting explanations, you can consider everything with a specific example.

The bath visitor stays in a room filled with a lot of hot steam. The person breathes in this vapor. It is known that people breathe oxygen, and they already exhale carbon dioxide. In the absence of sufficient air exchange, after some time, a person will simply get sick.

That is why ventilation in the bath should be as efficient as possible and made in full accordance with the technology. There are several types of ventilation systems. Explore the specifics of each option and choose the method that best suits your case.

Ventilation systems are installed to solve two main tasks, namely:

ensuring the flow of clean air into the bath;
removal of exhaust air from the steam room.

Additionally, ventilation provides faster and better drying of the steam room. It is necessary to study the features of existing ventilation systems and understand the order of their installation in order to get the most efficient and high-quality air exchange.

It is important that during the operation of the ventilation system the temperature regime characteristic of the bath is not disturbed. Air exchange must be organized in such a way that there are no violations of the distribution of temperature flows in the bath. Cool air in the steam room can be located only on the floor. And the higher to the ceiling, the higher the air temperature should be.

Ventilation should not remove clean air from the bath. A properly equipped system supplies fresh air to the room and removes waste air. Errors in the installation of the system will lead to extremely unfavorable consequences for both the bath and its visitors.

The main types of ventilation systems

There are several types of air exchange systems suitable for use in a bath, namely:

Exhaust air is removed from the bath through a special ventilation box. The air exchange installation technology requires that the box be installed diagonally to the inlet through which fresh air enters the bath.

Take care of the ventilation device in all rooms of the bath, not just in the steam room. The dressing room, rest room and other bath rooms should also be well ventilated.

What you need to know about floor ventilation?

Quite often, the owners of the baths forget that the floor of the steam room must also be properly ventilated. Such forgetfulness leads to a very rapid deterioration of the floor construction elements and, in general, a deterioration in the characteristics of the bath.

The floors are in constant contact with water. Without a well-organized air exchange, the floor will collapse very quickly, and the floor covering will have to be changed in 2-3 years.

You need to think about floor ventilation even at the construction stage of the bath, because it will be much more difficult to create a high-quality air exchange in an already finished room.

First step. Make small vents in opposite walls of the plinth. It is best to provide for these vents even at the stage of construction of the concrete base of the bath. Any holes in the finished structure will result in some reduction in the strength of the building.

Second phase. Make one ventilation hole in opposite walls of the serviced room. Through them, clean air will flow into the room. The holes must be through. It is recommended to close the finished ducts with special ventilation grilles. Such protection will not allow all sorts of rodents and other pests to enter the bath.

Stage three. When building the stove, make sure that the blower is slightly below the level of the finished floor. Thanks to this arrangement, the oven will also start operating in the exhaust mode.

Stage four. Install floor boards. When laying them, you need to leave gaps with a width of about 7-10 mm. Water can flow down through these slots. If the liquid lingers on the floor every time, the boards will rot very quickly.

Quite often, floor ventilation is set up "according to Bast". With this technology, fresh air comes from under the stove, and exhaust oxygen is removed through a hole in the ceiling.

In accordance with the requirements of fire safety, a metal sheet must lie near the sauna stove. It is near this sheet that an opening is created to supply fresh air to the bath.

A special exhaust box is required for such air exchange. You can buy the box ready-made or assemble it yourself from the boards. The inner surface of the exhaust duct must be covered with foil. The size of the box should be about 15-20% larger than the diameter of the chimney.

Ventilation "according to Bast" is the best option for those cases when the stove is located directly in the steam room. In such a situation, ventilation ducts can be equipped even directly in a brick podium.

Pay attention to the location of the sauna stove. If the stove is located directly in the steam room, then natural air exchange is present initially. Only you do not need to rely solely on it - such ventilation works only when the stove is running.

The most optimal ventilation installation option is the arrangement of air exchange channels on the opposite walls of the bath. They should be at different heights.

It is not recommended to place the ventilation holes too high. Although in most other cases it is recommended to make an exhaust hole directly under the ceiling, in saunas there are slightly different rules. If you place the hood directly under the ceiling, hot air will escape very quickly from the room.

For baths, the optimal height for placing ventilation openings is a level equal to 1-1.5 m.

Bath ventilation installation guide

There are several simple ways to organize effective air exchange in a bath. Explore each of them and choose the best one for your steam room.

The first way. Create a fresh air hole. It should be behind the stove, about half a meter from the floor. Make an opening for the exhaust air outlet on the side opposite to the inlet, at a height of about 30 cm from the floor level. Install the fan into the outlet.

The lower you place the exhaust ventilation duct, the more intensive the air exchange will be.

However, you don't need to be too zealous either. Try to make holes at the recommended height, as these values are the most optimal. It is recommended to cover the openings with ventilation grilles.

Second way. With this air exchange, both vents will be on the same wall. The work will be carried out with a wall parallel to the stove. The suction channel is created at a level of about 30 cm from the floor, the exhaust canal is created at the same distance from the ceiling of the bath. The exhaust outlet is equipped with a fan. Cover open channels with ventilation grilles.

Third way. Make an air intake hole behind the sauna stove. Place the suction channel about 20 cm from the floor surface. The exhaust duct is made at about the same height, but in the opposite wall. The exhaust outlet is equipped with a fan. Cover open channels with ventilation grilles.

Fourth way. This air exchange option is perfect for baths, the flooring of which is laid with slots for water drainage. Make an inlet behind the oven unit at a distance of about 30 cm from the floor surface. An exhaust hole in the case of such ventilation is not done - the exhaust air will leave the bath through the slots of the floor covering, and then it will be discharged outside through a common ventilation pipe.

Fifth way. Such ventilation is ideal for baths with a constantly operating oven unit. Install the inlet channel opposite the stove, stepping back about 30 cm from the floor. The oven will perform the function of the hood.

Thus, the order of arrangement of ventilation practically does not differ in all the considered methods. Each of them involves the creation of one or two holes, only the place and height of their placement change.

You can also make the holes yourself with your own hands. Brick walls can be easily traversed with a perforator, and log walls with any suitable tool, for example, a wood drill. It is recommended to insert plastic pipes into the finished holes. Do not forget about protective ventilation grilles. In the future, you are unlikely to be delighted with uninvited guests in the form of rodents.

Happy work!

Video - Ventilation in the bath with your own hands

The positive effect of regular bath procedures on the body is invaluable. At the same time, a bath is not just healthy, it is also a spiritual pastime, rest and gatherings. However, all the benefits will easily be covered by the difficulties that will certainly appear if there is no effective ventilation in the bath.

The importance of the system

Even in the old days, architects understood that the lack of fresh air in the bath can quickly cause dampness, mold, and fungal spores, which inevitably leads to the destruction of the structure. That is why, even in ancient times, builders left small gaps between the logs - they helped to improve air exchange and high-quality ventilation. Today, these primitive technologies have been replaced by modern, efficient systems that require effort, money and time for planning and installation.

Some homeowners skip this stage of work, but this is a very big mistake, since after a couple of years such buildings will simply become unusable due to constantly high humidity, and if the bath is built using frame technology, then its service life will be even less. The first sign of the beginning of destruction will be a musty smell, which will be most noticeable at the moment the stove is kindled. This will negate any pleasure from the procedure. Being in such a steam room is not only unpleasant, but also quite dangerous to life and health, since carbon monoxide accumulates in the air, spores of fungi and mold, which provoke the development of dangerous diseases of the bronchopulmonary system.

Effective ventilation in the bath must certainly comply with the basic requirements and safety principles:

Correct redistribution of air masses. As you know from the school physics course, high-temperature air masses rush up, and cold ones, on the contrary, go down. Therefore, the streams should be directed so that the feet do not freeze, and the sunbeds have a comfortable temperature.
Maintaining a preset heating level in the steam room. Ventilation should under no circumstances interfere with the functionality of the steam room, that is, air cooling is unacceptable.
Application of waterproof materials. For the arrangement of steam rooms and the organization of ventilation in them, it is necessary to use materials that are resistant to humidity and high temperatures.

The main difficulty in creating an effective air exchange system is that it faces the task of quickly removing hot humid air from all parts of the bath, but at the same time it is required to prevent the temperature in the hot steam room from falling, therefore modern systems, as a rule, use the installation of hoods that do not allow blowing cold air from the street. The presence of such systems is of fundamental importance for buildings equipped with solid fuel and gas furnaces, since such schemes require a large amount of oxygen to support the combustion process.

How it works?

High-quality ventilation in a steam room consists of ventilation and complete drying of all functional areas, as well as walls, floors, attic and the entire roof area. Exhaust openings in the attic are made in the form of small windows, as well as aerators or soffits - this largely depends on the version of the roof and the materials of its manufacture. If the building is insulated, then a counter-lattice is additionally mounted, which allows ventilation between the layer of thermal insulation material and other layers of the roofing cake to be achieved. It is also installed to ventilate wall structures, which is very important to prevent the formation of condensation in the bath.

But for the best drying of the floors, a volley ventilation system is used or a ventilated floor is arranged. Such options should be envisaged even at the planning stage of construction work. To do this, lay a rough floor and pour concrete at an angle, then lay the boards in such a way that there are small gaps between them, through which excessive moisture is removed.

It should be noted that absolutely all bath rooms need ventilation: steam room, sink, rest room, as well as other rooms. In order for ventilation to be most effective, it is necessary to select in advance such a scheme that will correspond to the characteristics of the bath and the conditions of its operation.

Experienced builders do not advise to carry out complex ventilation systems and recommend giving preference to the simplest and most familiar techniques that may be suitable for each individual case. Here, the statement that the simpler the better is 100% true, and in terms of its cost, this option will be much cheaper.

The ventilation principle is based on the laws of physics. As a rule, in such rooms, 2 windows are cut out: one of them is responsible for the supply of fresh outside air, and the second allows the overheated and humid outside to escape. On how these windows are located in relation to each other, it largely depends on which zone of the complex and with what intensity the air heated from the firebox will penetrate, since it moves under the influence of cold air masses coming from the street. This explains the fact that in some baths, instead of a single outlet, two are cut out, which makes it possible to redirect heat fluxes in the desired direction.

The dimensions of the windows are also of fundamental importance, as well as the possibility of full or partial regulation of the clearance. To do this, special latches are fixed on them to cover any open slots.

It is very important to make the correct calculations of the window, taking into account the size of the room. If the windows are too large, then the steam room will simply not be able to warm up to the required temperature and will have to spend more electricity. And if the windows turn out to be too small, then the intensity of the flow will be reduced and a complete oversaturation of the air with water vapor may occur.

The size and location of ventilation windows primarily affects the ingress and uniform mixing of air, as well as its removal from the overheated room. As for the uneven distribution of temperatures in different parts of the steam room, it will not be possible to completely avoid this phenomenon, but it is possible to ensure that the effect is invisible to the visitors of the steam room and the washing room and does not cause any discomfort.

Views

High-quality ventilation of the bath rooms extends the life of the steam room up to 50 years and even more. The variant of the ventilation system in each case is selected individually and is largely determined by the location of the building and the materials that were used in its construction. According to the basic principle of operation, all the options for arranging ventilation developed to date are divided into natural, forced, and also combined.

Natural ventilation assumes that the change of air is carried out due to the unimpeded flow of flows from the outside, their mixing with the air layers of paired rooms and the removal of waste through special holes.

Forced the system is based on the use of fans. As a rule, they are installed on the hood and much less often on the inflow. Usually, fans are installed not only in the steam room, but also in the washing room, as well as in the rest room.

Combined option, as the name suggests, it includes elements of natural and forced ventilation.

Among the popular schemes, the most widespread is "bastu". It involves the formation of a small hole with an adjustable valve, which works for the inflow and is usually located behind or under the furnace.

As additional elements above the stove, vents are equipped, which are controlled by a latch and a valve - it is through them that air enters from the outside through the vents from the underground. Usually, the opening of such a box remains closed for a certain period, however, as soon as there is a need to reduce the humidity level in the bath, both exhaust valves open. This scheme could be considered ideal, if not for some of its limitations. Unfortunately, it is far from suitable in every case, therefore, in some situations, the installation of an exhaust system becomes a more preferable ventilation option - for this, a fan is attached to the lower part of the box. If you install it in the inlet behind the stove, you can get the inlet type of ventilation.

There is another scheme that is quite often used in steam rooms - with it, moist superheated air is removed from the steam room through the upper and lower openings equipped with valves, and fresh air is supplied through vents in the floor under the firebox. From the outside of the building, such openings are connected to each other by a special ventilation duct. Less often, an exhaust hood is equipped in baths, in which there is only one channel for the entry of air jets and one for their removal, while both are equipped at the same height from the floor level: one is located behind the stove, and the second is opposite on the opposite wall. This system requires mandatory installation of forced ventilation.

The most unfortunate method involves the arrangement of both inflow and exhaust on one side opposite the firebox. In such a system, fresh air entering from the street seeks its way to the stove and, during its movement, bumps into the feet of the soaring ones. Thus, a draft is created, which significantly reduces the level of comfort from being in the steam room. Nevertheless, such an arrangement is also quite common when there is no technical possibility to make holes from different sides of the room.

Materials (edit)

The choice of ventilation system for a bath is largely influenced by the type of structure and the material from which it is made. If the bath is equipped in a separate building, then it is quite simple to plan and install the most preferred type of ventilation. But if the bath has a common wall with living rooms, then ventilation must be taken especially carefully to prevent waterlogging and decay of the wall.

The ventilation system in the baths of the second type can only be forced, that is, it must include a fan, which will contribute to the effective drying of the wall. The ventilation of the bath can be connected to the elements of the general ventilation of the house or go outside independently. Ventilation ducts in frame buildings are equipped directly in the walls, and later taken out to the roof or even higher. For maximum air flow, functional air vents are mounted in the foundation or a ventilation valve is installed.

The peculiarity of buildings using the frame method is such that the walls in them are covered with a large number of heat-insulating layers, which completely excludes the possibility of arranging natural ventilation. That is why the best option here would be to create a supply and exhaust ventilation system. In order for the air exchange to be of the highest quality, they use the creation of two channels: one is placed near the floor and supplemented with a fan, it is used for the inflow, and the second serves to remove the exhaust air - it is mounted a little higher. The openings of such holes are closed with dampers.

In the baths, built of gas blocks and foam blocks, in connection with the individual characteristics of the material, galvanized air ducts are equipped. To do this, they purchase ready-made pipes, some even make them from simple sewer pipes. Some craftsmen create a ventilation duct on their own from galvanized leaves, having previously given them the necessary configuration and reliably sealing the joints. As a rule, in such buildings, air ducts are laid over the side walls.

The easiest way is to arrange ventilation in a classic Russian log sauna. It makes sense to equip a natural extraction system here. If the wood is breathable, gaps are formed between the logs from the floor to the lower edge, and windows are provided in all rooms of the bath, then additional ventilation structures will not be required. However, the problem often arises of creating optimal proportions between the air entering from the outside and leaving the air. To prevent drafts and not to “heat the street”, experts recommend that you additionally insulate the bath well and equip small holes with special valves inside the heat-insulating material, which serve for the flow in and out.

In buildings made of wood, the method of volley ventilation is often used, in which all windows and doors are opened at the same time.

Brick buildings initially do not provide for the possibility of air exchange, therefore any natural hood is absolutely excluded here. Because of this, ventilation should be planned even at the stage of drawing up a construction project. At the same time, it is important to know exactly how many bathers will take bath procedures. If the bathhouse is being built for a small family, then you can simply arrange a small inlet near the stove and an exhaust outlet under the ceiling, and if the structure is focused on a large company, then forced options should be preferred.

How to make it yourself?

In order to create comfortable conditions in the steam room and other bath rooms, it is necessary to correctly equip the ventilation system. It is possible to carry out it in the bath both on your own and with the assistance of specialists. This will require a project of work, materials and tools, as well as a little effort and time.

What do you need?

Preparation is required for the installation of ventilation ducts in the bath. The work will need components:

several ventilation valves;
gate valve;
metal grill;
mosquito net;
ventilation box;
corrugated air duct;
hygrometer;
fan;

thermometer;
metallized scotch tape;
clamp;
mounting foam;
sealant;
fasteners;
decorative overlays for facing inlet and outlet openings.

By the way, the latter are widely represented in any store in a variety of colors and textures, so getting the best option will not be a problem. Ventilation valves are installed on the exhaust and supply openings. They can vary in shape, size and material of manufacture. Gate valves are used to quickly open or close openings. They are made from a wide variety of materials, and some home craftsmen even make them with their own hands, and in terms of strength and fixation strength, they are in no way inferior to store options.

A lattice with a grid, as in ordinary houses, is necessary in order to create a barrier in the way of insects and rodents, whose presence is highly undesirable either at home or in the bath. Most often they are made of metal, but there are options made of heat-resistant plastic.

The box, as a rule, is fixed from the outer wall, but if there is no technical possibility for this, it is simply laid along the top. This arrangement is typical for aerated concrete buildings. Some people make a box on their own using corrugated pipes. Keep in mind that plastic options are not suitable for steam rooms, as most types of plastics begin to deform when exposed to high temperatures.

The fan in the steam room is used both for supplying and removing exhaust air. It is optimal if in the room it will work only in a general direction. Such a device should be purchased in a heat-resistant version, which is specially made for Finnish saunas and baths. Thermo and hygrometer are used to make the use of the bath as practical as possible. For example, in systems with forced ventilation, temperature sensors are often installed that analyze the real state of the air and, depending on its performance, open the supply tap or start the hood.

Layout during the construction of a steam room

It is optimal if the entire ventilation system is thought out in advance - even at the stage of building design. To choose the most suitable design, it is worth focusing on some of the nuances of installation work. The ventilation system, as a rule, is laid during the construction phase of the bath, it is at this time that all the necessary channels are laid and openings are formed into which they will later be walled up or to which they will be attached. The adjustable windows themselves are fixed only after the decoration of the complex has been completed.

All ventilation openings usually have the same size, while if the task is to increase the degree of air outflow, then the exhaust window is made slightly larger than the supply window, but in no case is it vice versa. The formation of an exhaust hole with a diameter lower than that of the supply one is strictly not allowed, because such a design can pose a threat to the life and health of users.

Of course, dampers and dampers must be provided in the system, and the latter are considered the most preferable option, since they allow you to close the holes with the greatest tightness without the formation of any gaps. Adjustable dampers are also important because the air flow depends not only on the size of the window, but also on the season. In winter, when negative temperatures prevail outside the window, cold air masses penetrate more intensively into the bathhouse, which is why in the autumn-winter period the windows are partially opened, thereby delaying the influx of large volumes of frosty air masses.

As for the ventilation window, the size of its cross-section is calculated based on the volume of the steam room. Conventionally, a standard was adopted, according to which the window area must correspond to 24 cm2 for each cubic meter of space. If the calculations are performed with violations and deviations in one direction or another, then the room will be too much ventilated, or vice versa.

Even at the design stage of the bath, it should be remembered that ventilation windows should not be located exactly opposite each other at the same level. In this case, warm air masses will not have normal circulation and will not be able to cover all the required heating areas. The exhaust openings should be located slightly below the ceiling. This is due to the fact that warm air rises upward. If there is an outlet for overheated air flows in the system, then they are effectively removed outside, and if the holes are located low, then the exhaust air cannot find a place for removal and the general microclimate in the room becomes uncomfortable.

Separately, ventilation of the floor should be provided, since with constant contact with water, wooden surfaces lose their performance after 3-5 years, therefore there are important requirements for a ventilated floor:

to form the possibility of a flow in the foundation, it is necessary to build small vents;
the floor should be laid in such a way that there are gaps of up to one centimeter between the boards;
the finished floor must be laid without fail above the level of the blower, which contributes to the fact that the oven begins to work as an additional hood;
after taking bath procedures, you should leave the front door completely open until the floor dries out.

As for the dressing room, it is easiest to arrange ventilation here, since there is no direct contact with water in such a room. As a rule, a combined or natural ventilation method is formed here, when cool air enters through the supply duct, and is removed using the exhaust mechanism of the steam room, where it gets under the action of a fan.

In addition, it is allowed to install ventilators here, which may require connecting to an electric current and going outside. As for the washing room, forced ventilation is usually built here, and air exchange is carried out with the help of an electric motor.

We organize a hood in an already built bath

Even ancient architects, far from the laws of physics, invented a method of ventilation, which was based on the creation of natural draft. Depending on how the bath was heated - in black or white, it also depended on where the heated air was discharged. In the first case, the stove did not function during direct vaping, therefore, open windows and doors were used for ventilation. The white scheme provides for the construction of a chimney. As already mentioned, the main elements of the air exchange system should be laid even at the construction stage, but there are options when it becomes necessary to equip an exhaust hood in an already built building.

To do this, you need to punch holes directly in the walls and supplement them with special plugs. One hole is punched in the area of the furnace blowing, and the second - near the ceiling on the opposite side. Of course, this is easiest to do if the sauna is built of logs. If the building is built of aerated concrete and even more so of brick, then it will be much more problematic to form holes and equip the hood, since in the process of such work it is possible to break the integrity of the walls in the wrong place, and the risk of destruction of the bath as a whole is quite high. That is why you should not do ventilation yourself in already operated baths. Entrust these works to professionals who have the necessary skills and special tools. But if you are still determined to do all the work yourself, study the step-by-step guide.

In conclusion, it should be noted once again that the basic principles of creating an effective ventilation system largely depend on the dimensions of the bath and the materials from which they are made. However, in any case, there are a number of requirements that must be observed regardless of the specified parameters. Each steam room must have at least two holes. One is used for the inflow, the second for the removal of air masses. If you plan in advance a hood in a bathhouse under construction, you can avoid serious problems with the installation of the ventilation system, which can cause disturbances in air exchange in the steam area.

It is absolutely unacceptable that the installed ventilation creates the following problems: