For the proper operation of the ventilation system, for effective control of air flows, it is necessary to install special control shut-off devices - valves. These components will be required if there is a need to change the volume or speed of the air flow passing through the air ducts in ventilation systems. In this case, various types of valves are mounted on the flow path: check, throttle, multi-leaf or hermetic.
High quality from RoomKlimat
RoomKlimat offers a wide range of accessories for air ducts and ventilation systems, which you can buy from us at the best prices in Moscow. The catalogs of our company include valves of the following types:
Reverse;
With manual damper;
Under the electric drive;
Regulatory.
All products presented in the RoomKlimat online store are of high quality and reliable performance and are manufactured in accordance with established standards. You can order valves from our company both wholesale and retail. We offer low prices, high quality and fast delivery.
Often the ventilation system does not work efficiently and part of the air penetrates from the ventilation duct back into the apartment. The effect of reverse draft ventilation is especially noticeable in the kitchens or in the bathrooms of apartments. Check valves will help fight unpleasant odors.
The principle of operation of the check valve ventilation
Check valves in ventilation are called a group of protective devices to prevent the rotation of the air flow in exhaust ventilation systems or simply the reverse draft of ventilation in apartments. The valve passes air in the right direction, inhibiting the reverse movement. Check valves for exhaust ventilation work automatically and this is the main plus of their use. In ventilation systems of residential and public buildings, check valves are used to prevent air from entering a common ventilation duct into individual rooms.
Check valves for exhaust ventilation work in systems with natural and mechanical draft. The valve protects against the penetration of insects, dust into domestic ventilation.
If the system is not equipped with a check valve, drafts may occur.
Types of ventilation check valves
The main structural part of any non-return valve for natural ventilation is the shutter. It is he who does not allow air to pass in an undesirable direction.
There are two types of round and rectangular check valves for ventilation:
- with a gate in the form of a spool;
- with a shutter in the form of a disk or flap.
The former are used to work with liquid media. The second ones are designed specifically for ventilation. They are available with a horizontal axis of rotation or vertical, as well as single-leaf and double-leaf.
Check valves for ventilation are produced in rectangular and round, with different cross-sectional diameters.
The main parameter when choosing a check valve is its capacity.
Non-return valves for natural ventilation are easy to manufacture and very reliable.
They are made of plastic or metal, the material is selected depending on the characteristics of the system. In vertical pipelines, the air flow moves vertically, so the valve is mounted horizontally, which ensures the correct operation of the valve.
The most commonly used are round and rectangular check valves with a capacity of 4 to 6 m/s. They work silently and efficiently. They are installed both independently and complete with an exhaust device.
All check valves for rectangular or round ventilation are also divided into:
- Heated. Such check valves for ventilation with an electric drive have the advantage: no condensate is collected in the system, and the structure will not be covered with frost in severe frosts;
- Without heating. Good for indoor use only.
The presence of an electric drive at the check valve for ventilation requires the participation of an electrician in its connection.
Although the device is cheap, the check valve for ventilation can be assembled with your own hands, but more on that later.
Check valve design for ventilation
The device of the check valve is very simple: the flap disc is attached to the axis, allowing it to swing freely. To cover the valve when the fan stops, a plumb line is attached. Vent valves can be rectangular, round or square.
Industrial models differ from non-return valves for domestic ventilation in diameter and material, they belong to the explosion-proof category, although the device is the same.
The diameter of a round or rectangular check valve for industrial ventilation can be from 125 to 1000 mm, they are installed in explosive industries.
The butterfly valve model with two blades is widely used.
Butterfly devices are often made of metal, the axis for attaching the blades is installed in the middle of the section. As soon as the fan stops, the blades cover the section and the reverse draft of the ventilation in the apartment stops. The diameters of the bicuspid valves vary from 100 - 315 mm.
An improved modification of the "butterfly" is equipped with seals that reduce noise during operation of the blades.
Very often used for ventilation in the kitchen check valve in the form of blinds or petals (inertial grille). There are several blades in the design, they are located on horizontal axes.
How to choose a check valve
When purchasing a check valve for kitchen ventilation or in a bathroom, you need to take into account the speed of air movement, because the shutter must respond to even the slightest flow. Poor draft in the system is the main problem when organizing a natural ventilation system. Therefore, most owners combine the valve with an exhaust fan. To cover the structure from the side of the room, a beautiful ventilation grill is installed.
But in order for the natural ventilation system to work flawlessly, it is important to choose the right check valve. Otherwise, back draft in the ventilation of an apartment building will continue to poison the existence of residents.
You should pay attention to:
- section shape;
- section diameter;
- valve material;
- valve device;
- valve purpose;
- manufacturer (affects more on the price than on the quality of the simplest mechanism).
You can purchase a ready-made kit of a fan and a check valve. Here it is necessary to pay attention to the power of the fan. For the kitchen, it is suitable with a factor of 10, and for the bathroom and toilet, 7 will be enough.
When purchasing a non-return valve for domestic ventilation of a private house, it is important to take into account climatic conditions. For example, a "butterfly" will be covered with ice faster than a single-axle structure. In private houses, in contrast to apartment buildings, residents are not annoyed by reverse draft in the apartment, but by wind blowing into the ventilation and penetration of rodents into it.
Do-it-yourself check valve for ventilation
The installation of a do-it-yourself ventilation check valve is especially relevant for residents of the last floors of houses, where the problem of dragging "foreign" odors through the air ducts of the general exchange system is common.
We offer an improved model of the ventilation check valve with an electric drive and a fan.
Thick plastic or textolite is suitable for the base of the kitchen ventilation check valve. You need a plate with a size that covers the outlet of the exhaust duct and a thickness of not more than 4 mm. Markings are made on the plate: a grid the size of a fan hole, as well as holes for mounting to the wall (at the corners) and for mounting the fan.
The larger the grid cells, the denser the leaf material must be!
To prevent air from “walking” between the base and the fan, a rubber gasket is used.
To prevent not only reverse draft in the ventilation of an apartment building, but also the penetration of insects, a small plastic mesh or even a nylon from pantyhose is attached to the base grate. The latter is easily replaced. And so that the residents are not disturbed by the vibration from the fan motor, rubber shock absorbers are used during installation.
Shutters are used from thick polyethylene (not less than 0.1 mm). The film should be perfectly smooth, the smallest waviness will break the tightness of the ventilation, and the reverse draft in the apartment building will resume. You can mount the sashes on adhesive tape with a fabric base. Detailed instructions for making flaps for a plastic ventilation check valve in the video:
We recommend cutting the sashes in place, from an already glued piece of film. Moreover, if it is slightly wrinkled during operation, it must be changed. Two sashes are cut between themselves only at the very end of the process. You need to cut with a sharp construction blade.
Use self-adhesive foam tape to ensure there is no gap between the homemade plastic check valve for ventilation and the wall.
During operation, it is necessary to periodically clean or change the plastic mesh, which is clogged with dust.
With proper manufacture, such a home-made plastic check valve for ventilation will last for more than one year. And the residents of the apartment will permanently get rid of the reverse draft, which is typical for the ventilation of apartment buildings.
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Modern technologies make our home more and more airtight. Metal-plastic windows, laminated surfaces and stretch ceilings interfere with natural ventilation, which is why dampness and mold develop in houses. Households suddenly begin to suffer from allergies and frequent respiratory diseases - this is also a side effect of the complete sealing of the house. Stagnant air is replete with allergens, pathogenic bacteria and microorganisms actively multiply in it. That is why it is important to install a supply valve into the wall, which will provide access to street air into the room and at the same time prevent drafts from appearing.
The supply valve is a simple device for ventilation
The main purpose of the supply unit is to provide fresh air access to the room. Under the condition of normal operation, the air supply device passes an average of up to thirty cubic meters of air per hour into the room, which corresponds to the physiological needs of one person.
The device consists of several elements:
- Air tube. Usually this part of the device is made of plastic.
- Grille (metal or plastic) to protect the outside of the duct.
- Inner insert with cap and air filter.
Some devices are additionally equipped with a noise isolator and. These additional elements do not allow the supply ventilation valve in the wall to freeze in severe frosts and block street noise.
The hygroregulation system automatically opens the valve if there is an excess of standard humidity readings in the room.
The supply and exhaust valve can also be additionally equipped with:
- fan;
- temperature sensors;
- air recovery system;
- remote control.
Advantages and disadvantages of a wall inlet valve
Like any device, the ventilator has its undoubted advantages and disadvantages, which cannot be ignored. First about the good:
- With the use of the device, the need for constant opening and closing of windows is significantly reduced. This saves time and saves window mechanisms.
- The device acts as a noise insulator and filters the air from toxic urban impurities.
- The device has control functions, it can be adjusted to the needs of a particular home.
- Installation of the ventilator in the area of operation of heating devices significantly saves heat loss.
- The device has small dimensions, is almost invisible on the wall and does not interfere with the placement of furniture.
- The device has a relatively low price, is easy to assemble and can be manufactured and installed independently.
Useful information! Installing a supply unit in the area of the battery will lead to the fact that the cool air of the street will be heated by the heat of the radiator when it enters the room. The second option for installing the device is at the top of the wall, where the incoming air masses will mix with the heated air of the room.
Cons in using the device:
- To install a ventilation valve in the wall, it is necessary to make a hole, that is, in some way violate its integrity.
- Incorrect installation of the device can cause freezing of the wall.
- In the northern regions in winter, the ventilator can contribute to a drop in the temperature in the room to values that are uncomfortable for a person.
Types of ventilators
Supply devices differ in the following parameters:
- the presence of air flow regulation (mechanical or automatic);
- the presence of a sound insulator and insulation;
- the presence of additional elements;
- the possibility of complete isolation of the duct;
- size and appearance.
Air exchanger selection
Before buying a supply valve to the wall, you need to check it for compliance with some important criteria:
- The device should not be too cheap, a high-quality device equipped with the necessary number of functions costs at least a third of the average cost of a metal-plastic window.
- The damper must be installed directly into the window frame or into the wall next to the window. It is important to check the possibility of such an installation.
- It is necessary to determine the type of ventilator control – mechanical or automatic. The machine will greatly simplify the need to control the optimal temperature and humidity in the house.
- You should pay attention to the level of noise protection of the device.
- The ability of the valve to tolerate the temperature regime of the region.
Prices and popular models
Ventilation devices with a minimum set of functions are relatively inexpensive. The simplest model can be purchased for five hundred - eight hundred rubles. But the most effective models are considered in the price category of two to four thousand rubles.
Table 1. Average cost of supply valves to the wall
| Picture/Model | Average price, rub | Incoming air volume, cubic meter per hour | Diameter, mm | additional characteristics |
|---|---|---|---|---|
 KIV 125 | 1600 | 36-60 | 133 | mosquito net |
 Aereco | 4200 | 5-40 | 100-125 | Noise suppression |
 KPV-125 | 2450 | 54 | 125 | Heat and sound insulation |
 SVK V-75 | 2500 | 1,5-31 | 142 | Heat and sound insulation |
supply valve KIV 125
Supply damper EHA2, 5-35 m3/h, white, EAR201
Wall air damper KPV-125 – 500mm
supply valve SVK V-75
Features of the installation of the duct
Before installing the valve, it is necessary to determine its location. The best place for this purpose is considered to be a place near a heating radiator on a load-bearing wall.
- Step 1. Drilling a hole for installing an air exchanger. The hole diameter should be slightly larger than the valve tube. This will allow you to correctly expose the device and securely fix it in the wall.
- Step 2. Outside, on the wall in the area where the device is located, it is necessary to provide protection from rain. If it is not possible to do this (the valve outlet will be located in a place inaccessible for work), the hole must be made with a slight slope towards the street. So raindrops will not fall into the device.
- Step 3. The inlet valve is installed in the wall and fixed with building foam.
How to make a supply valve to the wall with your own hands
To make a simple device you will need:
The plastic pipe will be an air duct, the piece should correspond to the thickness of the wall (a small margin can be provided). The optimal diameter of the tube is 10 - 12 centimeters.
- A grill is fixed on one side of the tube, this will be the outer part of the device.
- A rolled-up insulation (mineral wool, expanded polystyrene) is inserted inside the tube. For this purpose, you can use pipe insulation. The thickness of the layer should be about two centimeters, this is enough to prevent freezing.
- Next, a foam filter is inserted into the tube.
- The last step is to install the valve. You can make it yourself or purchase a finished product at any ventilation equipment store.
Used to remove various odors. But sometimes it happens that it is through it that tobacco smoke from neighbors or something similar enters the dwelling. In addition, with drafts or strong winds, instead of an exhaust hood, ventilation can work as a supply. So how do you get rid of these problems? The solution can be a check valve for ventilation, which will prevent various odors from entering the house. Now let's try to understand what it is, how it works and how difficult it is to install it in your home.
Read in the article:
Check valve for ventilation - what is it for and how does it work
The essence of such a device is as follows: being in the open position, the valve passes air freely from the room to the outside. But at the same time, it is worth the flow to rush in the opposite direction, the device works, blocking the path inward. The essence of his work is quite simple. The petal is located inside in such a way that the flow can pass in one of the directions. In the case of a return, the air closes its own path by turning this petal across the pipe.
An additional advantage of such devices is the ability to adjust the speed of the air flow that passes through it. But the main thing for which a check valve for ventilation is needed is, of course, to prevent cold air from flowing through the shafts into the apartment. Although many underestimate its necessity. An example can be given. There is a gas leak in a neighboring apartment. And at the same time, the air from them comes back to you. And despite the fact that gas, basically, is now everywhere natural, and not liquefied, it has no smell. It is unlikely that there will be a person who wants to get into a similar situation.
And now, having figured out the function of such a device, why it is needed and how it works, it makes sense to go to some types and types that the manufacturer represents on store shelves.
What are the types of check valves for ventilation
Such devices can be with a vertical shutter, or with a horizontal one. Choosing a suitable air valve for ventilation should be based on the direction of flow in the mine. With the wrong choice, it may simply not work when it is needed. The materials from which the petals are made also differ. Ventilation check valves, the damper of which is made of metal, are considered more durable.
Expert opinion
Ask a specialist“A normal air exchange system is almost impossible to find nowadays. The haste of builders, little knowledge of such systems - all this affects the quality. That is why most often the installation of ventilation check valves remains the only way out.”
It is for this reason that such devices have become so widespread. Although, as absurd as it sounds, for all their popularity, many do not even know what they are and what they are for. But sometimes there is no other way out, such as installing such a valve for ventilation, does not even remain. For example, if you take apartments on the first floors of old houses, where dampness comes from the basements and therefore the walls are periodically covered with fungus. Or upper floors with roof leaks. It is in such cases that forced ventilation with the impossibility of inflow can help. Of course, the roof will not stop flowing from this, but the humidity in the room will decrease significantly.
Well, now it’s worth considering the types of such devices presented on the shelves of Russian stores.
Existing types of valves for ventilation and their features
There are three types of such devices:
- membrane;
- petal;
- butterflies.
Let's take a closer look at them now.
Diaphragm Type Check Valve
This type is most often used in apartments with natural ventilation. The fact is that the membrane in it is quite flexible and even a small natural flow is able, by bending the petals, to penetrate through it. In the opposite direction, the membrane does not allow air to pass, thus ensuring the operation of the check membrane valve.
Petal check valve and its features
This design looks like blinds, the plates of which open under natural air flow or with the help of. It is also a fairly common type that is used in apartments. Check valves for ventilation of petal type have gained popularity due to their compact size (they can be installed instead of a ventilation grill).
Butterfly valve, its device and principle of operation
The least common type, the principle of operation of which differs little from the membrane one, with the only difference being that two semicircular or rectangular petals, fixed by a common axis in the middle, act as a barrier in the butterfly check valve. Under the influence of air flow in the right direction, they open. They are mainly used in forced ventilation, although, like other types, they can be used in natural ventilation, although less often. The fact is that the metal petals do not compress with a weak flow, which means that there is no question of any passage of air.
Related article:
In the article, we will consider in detail the types of structures, the principle of operation, how to choose a place for installation, how to properly install the device with your own hands, useful tips and recommendations from specialists.
Also, all three types of check valves can be automatic, mechanical or electronically controlled. Such devices will be controlled either by a microcontroller and temperature and humidity sensors, or by a remote control at the necessary moments.
Possibilities of using non-return valves in kitchen ventilation
Probably, such devices are most widely used in the kitchens of Russian apartments. It is very convenient when the valve is installed, for example, on a built-in hood. Indeed, if during operation such a device draws in smoke from the hob with the help of a fan, then in the off state, odors may well enter through it, forcibly expelled by the hood operating at the neighbors. And this, you see, is not very pleasant. It is in this case that the non-return valve in the kitchen hood will come in handy.
It is important that even with such an air exchange device, it is necessary to think about duplication. After all, in addition to the hood above the stove, there is one more hole for ventilation in the kitchen, in which a non-return valve will also not be superfluous. With this arrangement, the most acceptable would be to install a butterfly in the hood and a membrane or petal type for natural ventilation.
Do I need to install a non-return valve in the bathroom
There should not be any disagreement here either - it is definitely needed. After all, it is not very pleasant when, while under the shower, you suddenly feel a breath of cold air. And there is enough moisture in such rooms to allow additional dampness to penetrate from neighbors. And although non-return valves are not a panacea for ventilation in the bathroom, they still retain the main air coming from the outside.
Note! To better ensure the capabilities of such devices, it is recommended to use forced ventilation, i.e. using fans.
Forced ventilation device and its pros and cons
It is quite convenient when, if there is any smell in the kitchen or dampness in the bathroom, you can turn on the fan, which will quickly remove unwanted air from the room. Often such devices are installed on windows or vents. And yet, in addition to positive qualities, they also have negative ones, such as the need to supply electricity to them.
And yet there are cases in which forced ventilation is indispensable, and they have already been mentioned earlier. However, the most interesting thing is that the devices that require connection can be both stationary and mobile. And if you choose a fan with a built-in check valve directly to the size of the window, then you can install it only at the necessary moments. The rest of the time he will clean up. For such devices, a dedicated connection is not required, because. for a while they can be powered through an extension cord.
Let's try to consider such devices in order to understand how they work.
How does the check valve interact with the fan
When installing a fan on the window of the room, it becomes possible to ventilate it faster. When voltage is applied, the blades begin to rotate, pulling air out of the room and opening the valve petals. Well, when turned off, the valve closes, blocking the access of cold street air to the apartment. As you can understand, the essence of the device is elementary.
It is also possible to install a valve with a mechanical drive, when the owner himself, manually, can close it or open it. In fact, the non-return valve on the hood with a fan works exactly according to this principle. The difference is only in the location - horizontal or vertical.
Ventilation grill with check valve: how to install it
Such a device is very convenient not only to use, but also to install. The fact is that special skills for its installation, as well as a specialized tool, are not required. It is enough to dismantle the old grate, and install a new one equipped with a check valve in its place.
In fact, working like blinds, deployed in the opposite direction, the device regulates air flow. With the help of such a grille equipped with a check valve for ventilation, extraneous odors are cut off, as well as cold street air. As for the acquisition of such devices, then there are no problems with it. And the cost of ventilation grilles with a valve these days is quite acceptable.
Exhaust tees and how to use them
It is no secret that when installing a built-in hood, a tee is required, which will allow you to both connect the equipment to the ventilation system and leave natural air exchange in the room. Nowadays, they are produced quite a lot, and various modifications. Of interest are just tees for hoods with check valves, while their number may be different.
Usually two check valves are built in - for the hood and for natural ventilation, but sometimes a backup valve is installed - on a common pipe. In general, tees with check valves for ventilation are not used so often. It is believed that one air damper at the input is enough. But here, of course, the taste and color.
Installation of a non-return valve on the hood in the kitchen
Just such an arrangement of the air damper is the most common. Well, this is quite natural, because putting one check valve for the hood is much cheaper than buying a tee with two or three. In addition, most often, such devices are already installed in modern forced ventilation devices. And if a conventional hood with an old-style check valve can still let a small amount of air back, then newer models are devoid of such a “sore”.
Expert opinion
HVAC design engineer (heating, ventilation and air conditioning) LLC "ASP North-West"
Ask a specialist“Some technical documentation says that an anti-return valve for the hood is built in. What is it to remember. In fact, this is the same check valve, but it works much faster and thereby prevents even the slightest ingress of external air. But what can be said for sure - it works only with forced ventilation, or it connects to the network and is controlled automatically.”
Video: installing a Domvent home ventilation valve
Do-it-yourself check valve
Even though the cost of such factory-made products is not too high, there will always be lovers of doing everything with their own hands. Check valves for ventilation are also no exception. Let's try to figure out if it is difficult and what is needed for such work.
It is done quite simply. For this you will need:
- ventilation grille;
- two soft plates (a film from a fluorographic apparatus may well be suitable);
- hot glue gun.
Plates are glued to the inner side of the lattice in such a way that they are fixed only on opposite sides. The middle parts should move freely and converge at the edges exactly in the middle. That, in fact, is all the work - the simplest home-made check valve is ready. The grate is put in place, after which it does not let air out of the mine. From the room, it passes freely, bending the plates.
Well, for those who think that it is better to purchase such a factory-made product, we offer a small overview of the models and their cost.
Prices for various types of check valves for ventilation
The range of prices for such devices is decent, and therefore we will give examples from various categories.
| Model | Producing country | Warranty period, months | Cost, rub. |
|---|---|---|---|
 Shuft RSK 100 | Russia | 12 | 260 |
 Shuft RSK 355 | Russia | 12 | 1800 |
 ATS 190 | Russia | 12 | 1900 |
 VENTS 2121 | Ukraine | No | 70 |
 KON | Czech | No | 850 |
As can be seen from the table, such devices are quite affordable. In addition, the ease of installation makes them even more attractive to the consumer. If you look at the cost, then you can buy a plastic check valve for ventilation even for 70 rubles, which is good news.
As for valves with additional equipment, the price categories here are slightly different.
| Model | Power, W | Voltage, V | Cost, rub. |
|---|---|---|---|
 SOLO 4C | 20 | 220 | 3400 |
 SILENT-100 | 20 | 220 | 5400 |
 SILENT-200 | 25 | 220 | 8500 |
 EDM 100C | 15 | 220 | 2500 |
 STANDARD 5C | 16-20 | 220 | 1100 |
For about this amount, you can buy a check valve for ventilation, which will provide a forced outflow of air.
Article
If the ventilation system does not work effectively, an unpleasant odor may appear in the room. This is due to the fact that the exhaust air, being pulled out of one room, returns to another, dragging along with it odors from the natural ventilation channel. This problem is especially strong in the bathroom and in the kitchen. To avoid this trouble, it is recommended to install a check valve for ventilation.
Functions and design features
Despite the simplicity of design, the exhaust valve performs a useful function, preventing the exhaust air from being drawn into the room. The reasons may be the following:
- Poor tightness of ventilation ducts.
- Vent blockage.
- Incorrect position of the hood.
- Increasing combustion thrust in a private house with stove heating.
- Violation of the movement of air flows due to the installation of a powerful hood in one of the apartments of a multi-storey building. This is also possible in cases where the air duct of an apartment building is designed without taking into account the possibility of installing devices for forced ventilation.
- Availability several hoods in the apartment, due to which an uneven pressure of air flows is created.
- Change in the external environment outside the walls of the house (change in the relief during construction work, demolition of buildings, etc.).
Therefore, in order for the movement of exhaust air to be normal, a check valve is mounted. The design of the reverse is simple: on a single axis there are blades that allow air to pass in only one direction. When the movement of air flows changes, the sash closes, preventing them from entering the room.
Device classification
Varieties of exhaust valves can be divided into several groups:
- By design.
- By type of control: manual and automatic.
- By type of installation: horizontal, vertical.
- Shape: round, rectangular. The choice of a round or rectangular valve depends on the shape and size of the air duct section.
- Throughput. Depending on the volume of air that passes through the valve per unit of time.
- According to the material of manufacture: metal and plastic. More often, a plastic check valve is installed for ventilation, as it is less noisy.
Right choice
When choosing a device, it is necessary to take into account the air flow rate inside the natural draft ventilation duct. It is important that the valve blades give in to even weak flows. Since weak draft is common for natural ventilation, a fan with a check valve is often mounted in it. At the same time, it is also important to have an idea of how to choose the right fan: its power is selected based on the area of the room. To calculate the efficiency of air exchange in each room, different indicators are taken into account.
To select the correct ventilation valve, you should pay attention to the ambient temperature. When installing on a channel leading through the wall to the street, it is recommended to use a "blind" type valve, since other types are not resistant to low temperatures. The price when choosing a device is not decisive, since it depends on factors such as the type of section, the dimensions of the structure, the material of manufacture, etc.
In addition, when choosing a suitable device, the method of installation should be taken into account. So, a single-leaf check valve for gravity action ventilation is installed strictly horizontally or vertically, while a butterfly valve can be installed at any angle.
Homemade check valve
The manufacture of a home-made exhaust shutter is relevant in cases where the ventilation duct is either of a non-standard shape or size. A home-made design will cost less than fitting the duct box to standard sizes. If natural ventilation functions in the house, it is better to make a check valve of a membrane or single-leaf type from a rigid material. Before making a check valve, you should pay attention to such nuances:
- The plate should fit snugly against the walls of the device case so that no gaps are formed that allow air to pass through.
- Knocking of the plate must be excluded, especially if the direction of the air flows in the duct changes frequently.
For the manufacture of blades, you can use mylar film, the diameter of which should exceed the opening of the ventilation pipe. To prevent the film from deforming during reverse thrust, you can attach a grate on which it will rest. The simplest non-return valves are made from a grid to which a film is glued on both sides.
How to install the device correctly
Installation of a check valve for ventilation is carried out at the beginning or end of the duct pipe. To do this, the round or square body of the device is inserted into the ventilation duct, on the walls of which the marking of its location is made. After that, holes for fastening are drilled at the marked points. The check valve is fixed with dowels. There should be no large gaps between the body and the walls of the channel. The gaps should be filled with sealant.
Installing a valve on the exhaust ventilation protects the premises of a house or apartment from the reverse penetration of polluted air. In order for the installation of the device to contribute to a high-quality air outflow, the installation must be carried out in compliance with the basic rules: the membrane must match the diameter of the ventilation duct opening, its tight fit to the grille, and carefully sealed gaps between the device body and the air duct box.
