Supply-exhaust ventilation should perform its functions at any time of the year and any weather, that is, to provide sufficient flow of clean air and removing spent. A big role in an effective air exchange is played by the check valve for ventilation. Such a device is often used in the system of ventilation of natural and forced type.

Causes of reverse thrust

Sometimes it is impossible to ventilate the room due to the return of air from the ventilation channel with an admixture of all sorts of smells. This happens when the balance of the volume of the incoming and outgoing air due to clogging or narrowing the total ventilation channel. And because of the installation of high power fans in other apartments, the exhaust air does not have time to be output and returns from other premises. More than this is the upper floors. Since the cuisine channels and the bathroom are connected, the fan installed in your own apartment in the bathroom will provoke the reverse craving toward the kitchen.

The problem of reverse traction

In the houses of old buildings, mines designed to smaller throughput airflow and do not cope with large volumes from modern powerful hoods. Organize an acceptable air exchange helps the reverse valve for ventilation. It helps to change the amount of air outlook and skip it only unidirectionally, blocking the movement back. Thanks to him, all sorts of smells of adjacent apartments do not fall into housing, and dust, fluff and insects fly from the street.

Principle of operation and internal device

Purpose valve assignment: adjust and be damper from reverse airflow. The principle of operation of the check valve is: the sash, hanging on the central or several parallel axes, rise under the head of the air flow in only one direction, and when the petals are lined (lamella), are lowered under their own weight or using springs, preventing reverse movement.

In addition to stopping the reverse flow in the valve, there is still a function of regulating the volume of the conductive air when the damper is rotated to a certain angle, the cross-section of the air duct changes. Devices are two-position, where only two positions "open" - "closed" and multiposition, when can be adjusted to change bandwidth.

Varieties and types

Consider specifications and types of check valves in several categories:

• Based on the form, three types can be distinguished: round; Rectangular or square.
  Apply such dimensions that are suitable for a specific air duct. In everyday life, for home, apartments, bathroom bathroom, the round valves with a diameter of 100-125 mm are used, for ventilation on production, with a diameter of 125 mm to 1000 mm. The length of the rectangular valves varies from 7mm to 72 mm, and the width (height) is from 100mm to 1000 mm.
• Material material may be metal (galvanized steel, aluminum alloy) or plastic. Products from plastic are more common, as they are less noise when opening and closing the blades. Because of its ease, they are more applied in everyday life, where the air pressure is not very large. Metal designs are characteristic of industrial models. They are heavier plastic and closed under the power of their own weight. They are more reliable and resistant to an aggressive environment belong to the explosion-proof category. But there are also disadvantages: metal is subject to corrosion, and condensate is collected on galvanized dampers.
• Mounting method is horizontal and vertical. It is set in one way or another on the basis of the technical data of the valve and the corresponding duct design of the air duct or exhaust ventilation.
• Control can be manual or electric. The valve with manual control is adjusted by hand with a lever or valve, and at a round - valve. Such devices are used in natural supply or exhaust ventilation. The electric valve is activated in the diagram with mechanical devices (fans, exhaust) and controls the volume of the passing air flow automatically (the sensors of the position of the flap).
• We can share all varieties of valves into two groups: heated (with electric) and without heating. The advantages of the heated valve are that it does not ignore in the cold and does not accumulate condensate. No heating is suitable only for use inside the house of the duct.
• According to the type of construction, there are such varieties: membrane; petal; butterfly; lattice.
  

Applying check valve

Ventilation of natural type

Apply both in the supply and exhaust ventilation. In the outer wall of the houses, a trimming vent valve is mounted, equipped with a check valve or damper. It can be equipped with air purification filter. The use of the supply valve in natural ventilation provides good access of clean air into a dwelling with reverse thrust and heat preservation. The valve or valve allows you to adjust the intensity of the air flow.

It also makes sense to install the lattice with moving blinds on the supply ducts. They direct the air flow only inside the room.

The use of flexible membrane in the ventilation grille in the kitchen is simply necessary, where the powerful flow from the exhaust and other rooms is displayed in one mine to prevent its return. The membrane design is simply obliged to be very sensitive to the slightest movements of air, since with the natural air exchange of large pressure does not happen.

In natural ventilation, you can not use a two-fledged valve with springs, requiring for opening a large pressure. In this system, a device with one petal is more efficient.

Application in case of forced system

It is well combined with such a device with mechanical devices for drawing, for example, a kitchen hood. Installation is made along with the hood.

In models where the hood with the check valve comes in the kit, it performs the role of the flap. When the hood is off, the flap closes the channel, preventing the penetration into the kitchen of odors from the common channel. The duct from the drawing should not close the opening of the exit to the overall ventilation shaft, leaving it for natural ventilation. In addition to the grid, you can install a single-olepole valve or a valve fan.

In more powerful hoods apply the butterfly valve. Such structures are attributed to additional costs. The channel from the drawing is removed directly into the street through the outer wall, pulling directly spent air. So that the cold air does not penetrate the house, an inertial grille is installed on the wall.

Inside the house or apartment for organizing the correct air circulation in all rooms, inertial grilles are installed in interior walls, and more often in the door. Such inertial lattices contribute to air movement towards the direction from the rooms towards the kitchen, to the total Ventcanal, and not vice versa.

The tonite with the check valve and its use

For high-quality air exchange, when installing air ducts, special tees use, which allow competently combine natural and forced ventilation.

Due to ineffective ventilation in the bathroom and bathroom, it is often observed in stagnation and mold formation. To prevent the incidence of third-party odors, as well as for rapidly removing moisture, an exhaust is exhausted with a check valve. But the power of the fan should not be big so that Central Ventkanal people manage to cope with the air flow.

It should be remembered that it is necessary to regularly clean all shut-off and regulating devices to maintain their performance.

How to choose a finished product

In the functioning of ventilation, the main problem is bad thrust. It is enhanced by combining all types of ventilation using the check valve.

Choosing the check valve must take into account the compatibility of all devices and mechanisms to the following factors:

• Shape and diameter of the cross section of the channels. Choose the valve and the fan in size corresponding to your duct so that there are no problems when installing. A variety of valve models have been developed with different round and square shapes and sizes. Usually, ducts and check valves are 100 mm in size. Square valves are securely proven, which are easily attached in square mines.
• The material from which the product is made should correspond to the type of system in order not to worsen its functioning. Indeed, in natural ventilation, the gate should react to the slightest air oscillation, it means to consist of the finest material. And in the production hoods of the device should be resistant in an aggressive medium and temperatures, so galvanized steel or aluminum is used here.
• Appointment and device. To consider for which room the valve is selected. It must correspond to the power of the fan used so that it is enough for the disclosure of the petals. For example, if a bathroom is sufficient with a coefficient of 7, then for the kitchen - 10. There are ready-made models in a set of fan with a valve.
• It is important to take into account the bandwidth of the check valve. In everyday life use products with a bandwidth of 4-6 m / s. The amount of air deposited from the apartment should not exceed the permeability of the total ventilation mines, otherwise it will be distributed to other apartments. Otherwise, it is necessary to install a separate air duct with the output to the street.
• By climatic conditions, some devices are mounted only indoors, as they do not wear low temperatures. For example, the butterfly from the frost will be covered by Founder. For a private house, it is necessary to take care of the characteristic bloody wind and the penetration of rodents.
  Properly chosen valve serve as a guarantee of the quality work of your ventilation and comfortable conditions for accommodation.

Rules for placement and installation with your own hands

Initially, we define the installation sites of the check valves in the ventilation scheme. Consider an example of mounting in a ventilation mine behind the fan.

1. Turn off the exhaust from the power supply and dismantle.
2. In the opening of the air duct insert the valve and mark the place of attachment on it. We take it out and drills on the outlined holes.
3. Again, insert the device into the channel and make the markup on the wall, then by driving the valve, drill the holes in the concrete opening using the jumper.
4. In the concrete we score dowels and screw the device.
5. The gaps along the edges thoroughly smear the silicone sealant in order to prevent air leakage and the attenuation of the stream power.
6. In completion, install the hood in place.

Recently, the assortment appeared check valves that can be installed in front of the fan - overhead. Their mount is not so troublesome - does not require dismantling the fan. The grill with the check valve is installed before entering the ventilation channel or at the output from it. It can easily be installed with your own hands, attaching to the effect on ventilation, using self-tapping screws or "liquid" nails.

At the exit of the ventilation shaft, the valve is applied a single gravitational action and double-to-use springs together with a powerful fan.

Creating your own hands

For natural type ventilation, it is not difficult to make the valve yourself.
Proceedings:

Output

All sorts of smells will not penetrate the dwelling if you install the check valve on ventilation. The simplest device allows you to organize high-quality and efficient ventilation of premises, supporting a favorable microclimate.

Trying to establish air exchange in a private house or apartment, we often make mistakes. For example, we put the feed valve of the ventilation in order to get rid of unpleasant odors penetrating the inside of the premises through the exhaust channels. We struggle with the consequences, the present cause of the phenomenon is the lack of air inflows. It is worth understanding when reverse ventilation valves really need, consider the types and methods of installing return devices with their own hands.

What do you need a check valve

The main function of the valve is to pass the air in only one direction, when the reverse stream occurs, immediately closed. It is quite simple: the flow section overlaps the flap rotating on the transverse axis inside the channel. Second option: The passage is closed with thin polymer petals.

Reference. All check valves used in heating, water supply and ventilation systems, combines a general property - high aerodynamic (hydraulic) resistance of the gas flow (water). Hence the conclusion: the air distribution elements can not be put, risking breaking the room ventilation scheme.

With natural ventilation, air masses slowly flow from the supply devices to exhaust, passing through all rooms

Before discing the scope of valves, we recall an important point: most household ventilation systems work naturally. The thrust of the vertical pipe or mine creates a vacuum and sucks the air, the fresh influx compensates for the loss. In what cases is the check valve:

1. When connecting the kitchen exhaust to the mine's outlet. To preserve the natural air exchange when the fan is turned off, the vent can connected to a tee with a return device.
2. If the forced release is organized using a horizontal duct, laid through the wall. After stopping the fan, the valve will not penetrate inside the cold air room outside.
3. In the supply and exhaust ventilation systems with forced motivation - to distribute streams.
4. When it is necessary to eliminate designer errors or installers of ventsystems with the lowest costs.

The grille with ventlip is not bad, it helps the wind on the upper floors of high-rise buildings. Another case: the end of the exhaust pipe is not raised high above the roof of the country house or poorly protected from the wind. But the influx will still be needed, otherwise weak traction will not open the valve flap.

Options for mounting the check valve on the duct kitchen hood

Improper use of elements

A common error is to install in the kitchen or in the toilet of the ventilation grid with an inverse air valve. Allegedly, he protects against sinks from neighboring apartments of a high-rise building. Why this approach is incorrect:

• the reason for the penetration of unpleasant odors - tipping the thrust in the ventilation mine;
• the thrust rolls over due to the lack of influx, the larger cross section (in the kitchen) causes a smaller channel (in the bathroom) to operate in the opposite direction, the air moves from top to bottom;
• if you set a compensating supply device into a window or wall, both pipes will start pulling out the exhaust air, extraneous odors will disappear;
• the ventilation grille with feedstip protects the apartment from "someone else's" air by 90%, but the remaining 5-10% gases will be faded - the sash does not fit hermetically;
• the work of natural ventilation without a tributary will not work.

Returning Railway Scheme - Without Influx, Kitchen Mine Tresses Air from the Bathroom Channel

Note. Like in a country house, read in a separate material.

1. According to the requirements of sanitary standards, exhaust from the bathroom (bathroom, toilet) is prohibited to combine into one channel with kitchen ventilation.
2. When the fans are disconnected, the toilet odors will be fastened to the kitchen.
3. When you start two fans at the same time it is difficult to predict the behavior of air flow. Both valves will open, but the unit from the bathroom "will transmit" the kitchen, since it is installed on a straight area.

Air from the kitchen and bathroom can not be reduced into one channel, the scheme is initially incorrect

Clarification. If the fan of the kitchen umbrella is more powerful, it "widespread" the bathroom unit and at least blocks the hood from the toilet.

Conclusion: For each room, a separate air duct is needed, as required by the norm. Then the check valves are installed at the outputs of horizontal pipes, so as not to let the cold from the street. Ventcanals from the shower and toilet are allowed to merge, as shown in the drawing.

Channels from the bathroom to connect is allowed. And so that with simultaneous operation of the fans, the air has not flowed into the adjacent pipe, we connect them at an angle of 45-60 °

Types of return devices

The following types of check valves are used in the premises ventilation systems:

• air dampers - gravitational and spring;
• petal (membrane);
• two-sided type "Butterfly".

Elements are made of plastic, aluminum alloy, galvanized or stainless steel. In some manufacturers (for example, "Vents") there are combined models - metal housing, plastic sash.

The valve from galvanizing is used primarily in industrial ventrics. Serve to cut off the reverse stream or adjust the amount of air - manually either the electric drive shown in the photo. Plastic ventilation reinforcement is used indoors, stainless - on the street.

Addition. The check valves also include ventilation grilles with horizontal rotary blinds. The principle of work is similar - under the action of gravity, rectangular flaps are closed, not the outer air inside the canal.

Let's give a short comment to the video. Not all words of the master correspond to reality, but one thing he does right: puts the outer grid with gravitational flaps.

Design and principle of work of dampers

Single check valve consists of such parts:

• corpus round or rectangular shape;
• from the inside to the walls attached a damper, which freely rotates on the transverse axis;
• in the closed position, the sash holds the spring (there is no gravitational models).

The axis of rotation of the spring-loaded flap coincides with the longitudinal axis of the pipeline, the normal position is closed. After starting the fan, the sash opens with a pressure of the air flow, when it is turned off automatically slams. The closure is accompanied by a characteristic sound, hence the second name of the valve - "clapper".

A two-dimensional "butterfly" is identical, but instead of one flap used 2, the spring is installed in the middle. Both types of ventlipans are capable of working only in systems of forced ventilation. The pressure of natural thrust is not enough to open the spring-loaded sash.

Shut-off "clappers" as part of other ventilation accessories - connectors and mounting plates

In single-handed gravitational valves, the axis of rotation of the flap is located eccentric, that is, shifted above the axis of the air duct. Thanks to this, the big half of the sash outweighs the smaller, which is why it closes without any springs. Here the right setting of the check valve plays:

• if you insert the element into the horizontal pipe according to the instructions (axis of rotation above the air duct center), the damper will immediately close;
• if you turn over the vent boum upside down, the passage will remain open;
• when installing on the vertical channel, the closing of the sash also depends on the position of the element.

Clapper for natural ventilation is placed in 2 ways: horizontally in a closed state or vertically, but on the upward stream. In other provisions, the behavior of the sash is difficult to predict, if the air reverse flow occurs, the valve may not work.

Scheme of work valve - "clappers". Due to the offset, the free flap automatically closes

Household "clappers" can be part of other ventilation accessories - connecting nipples, wall flanges. There are exhaust fans with a check valve - "Butterfly".

Membrane valves and gravitational lattices

In products of the first type, the function of the main shutter performs the membrane from a thin polymer film adjacent to the body or the slots of the ventilation grille from the inside. The film is attached to the central axis of the valve, the edges remain free.

Under the action of natural thrust or pressure of the fan, the extreme petals of the film are rejected, passing the air. With the reverse movement of gases, the lavsan membrane is adjacent to the frame, locking the passage. Petal type valves can go in a set of exhaust fans and lattices.

Note. It is such an air valve to make it easy to make it yourself. It is enough to attach to a conventional lattice 2 of the film petal, pressing the cardboard gasket with cutouts. Manufacturing instructions are shown below on video.

Multiple grilles operate on the principle of dampers that are lowered under their own weight. The scope of application is the exhaust channels of forced ventilation, derived from the walls through the walls. In horizontal pipes, natural traction does not occur.

The return element is selected depending on the ventilation and installation location:

1. To connect kitchen exhaust, use a gravitational action "clapboard" corresponding to the duct form. The task of this valve is the preservation of a natural air exchange during the inactivity of the fan.
2. The grille with the membrane valve (homemade or factory) is put in the opening of the exhaust mine, if the thrust is tipped into the gusts of the wind. From smells it is better to get rid of another method - install wall supply valves for.
3. In private houses, the air duct of the local exhaust is often paved directly through the outer wall. So that the cold air does not bloom in the wind inside the ventkanal, install a multistate exhaust grille.

Fresh air options in the room using the supply equipment

In mechanical ventilation systems with forced air supply, the valves are used according to the scheme and specification compiled by the designer. We do not advise you to develop such an air exchange yourself - errors will not be avoided, and the price of alteration will be too high.

Council. Build inexpensive plastic products for installation inside the rooms. The galvanism looks ugly, ventilation will have to sewer plasterboard.

How the check valve is installed

The installation of a multistate lattice and membrane outstage does not represent complexity and does not need a detailed description. Elements are attached to the wall and connect to air ducts according to the factory instruction.

One addition: When installing the outer lattice, the wall canal is better insulated. From direct contact of the emerging air with a cold wall pairs will begin to condense. After stopping the fan, the water will freeze and forms score.

If you decide to install a gravitational feed valve for drawing, consider such nuances:

Council. Before planting a check valve on silicone sealant, check the performance of the scheme. Insert the "flap" in the tee, turn on / stop the hood 5-10 times, changing performance. The damper should slap and open 100%.

Conclusion

As you can see, in the systems of home ventilation, the check valve is used infrequently. If you practice a solid approach to the organization of the air exchange, the return elements will not be needed at all. The kitchen hood without problems is connected to the exhaust inventory with the grid, the main thing is to ensure the influx. Exception - more complex schemes using 2-3 fans working alternately or simultaneously. There, the valves help direct streams or adjust the amount of passing air.

Installation of the check valve on ventilation solves the problem of penetration of odors from the street into the room. In private households, a situation may occur, when the installed ventilation system does not fully fulfill its functional value. In other words, the air saturated with smells is partially removed from the room, and there may also be a situation where foreign street odors come to the dwelling through ventilation channels.

This article will disclose in detail the question of what is the return valve, which there are varieties, and how to install this device with your own hands.

In contact with

Odnoklassniki.

Purpose

This type of mechanisms is intended to control the increase or decrease in the air flow in the ventilation system. The main task of the valve is the conclusion of clogged air, as well as the obstacle to the placement of various kinds of odors.

The design of this mechanism is quite simple, and includes the following elements:

• housing;
• the main axis on which the flap is attached;
• anti-honey, which automatically closes the blinds when stopping the fan.

It's important to know: The check valve does not in any way enhances the effect of the ventilation system. It only controls the flow of air.

The modern market of ventilation equipment today has a very wide range of check valves of various modifications.

Varieties

To choose correctly this device, you need to know how and where the mechanism will be used.

Depending on which material is made of the design, the check valves are separated into two types:

• galvanized (this species is well opposed to corrosion, but condensate accumulates on the walls);
• plastic (Practical and convenient enough when installed).

Depending on the form distinguish:

• rectangular;
• round.

It is worth noting: The selection of the check valve in the form largely depends on the section of the ventilation channels of the system.

Depending on the location of the flaps, these valves are divided into the following types:

• horizontal;
• vertical.

The choice in this case depends on the direction of the air flow in the ventilation system.

Depending on the functional purpose, the check valves are divided into the following types:

• The mechanism of the "Butterfly" type.

The flap of this type of valve consists of two plates, which are mutually refined.

The principle of operation lies in the fact that the plates are opened in the injected air flow, and are closed under the influence of the spring element. The most common use of this mechanism is a combination with a fairly powerful fan.

• Membrane household type.

A feature of the design is a flexible plastic flap, which is opened under the influence of the air pressure, and when it disappears it is hermetically pressed against the case.

This type of mechanism can be used only with low-power household exhaust fans.

• Petal type. The principle of action is absolutely similar to the previous case, however, with the difference that the flap is rigid and fixes on the axis.
• Gravitational type. A feature of the reverse valve of this model is that the plates are opened by air flow, and close under the action of their own weight.

Criteria for choice and installation

In order to choose the right check valve, it is necessary to follow the following recommendations:

1. 1. 1. 1. 1. 1. • the price must comply with the quality (the size of the mechanism may also affect the cost;
                  • it is necessary to take into account the natural factors of the region, so they can significantly affect the valve operation;
                  • pay attention to the appearance of the lattice of the mechanism - it must be decorative;
                  • included with the device it is desirable to choose a fan without which the check valve can turn into a normal valve.

When installing the check valve, it is necessary to adhere to the main rule, which is as follows: For the successful installation of the mechanism, it is necessary to clearly know the direction of movement of the air pressure, and directly the valve itself should be installed according to the attached scheme. If the flows are confused, then it is not necessary to talk about properly functioning the device. Leave the message and your contacts in the comments - we will contact you and make a publication better together!

With ineffective operation of the ventilation system in the room there may be an unpleasant odor. This is due to the fact that the exhaust air, stretching out of one room, returns to another, tightening with them odors from the channel of natural ventilation. A particularly similar problem is felt in the bathroom and in the kitchen. To avoid this trouble, it is recommended to install the check valve for ventilation.

Functions and design features

Despite the simplicity of the design, the exhaust valve performs a useful function, preventing the exhaust air to the inside of the room. The reasons may be the following:

• Bad tightness of ventilation moves.
• Vago Ventkanal.
• Incorrect exhaust arrangement.
• Strengthening thrust burning In a private house with furnace heating.
• Airflow Violation Due to the installation of a powerful exhaust in one of the apartments of a high-rise 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 multiple Extrazhkov In the apartment, due to which an uneven pressure of air flows is created.
• Change of external environment Behind the walls of the house (a change in the relief during construction work, demolition of buildings, etc.).

Therefore, that the movement of the exhaust air is normal, the return shutter is mounted. The design is simple: on the only axis there are blades that transmit air only in one direction. When changing the movement of air flows, the sash closes, preventing them from entering the room.

Classification of devices

Varieties of exhaust valves can be distributed over several groups:

1. By design.
2. By control type: manual and automatic.
3. By type of installation: horizontal, vertical.
   
4. In the form: Round, rectangular. The selection of a round or rectangular valve depends on the shape and size of the section of the air canal.
5. Through bandwidth. Depending on the air volume, which passes through the valve per unit of time.
6. By manufacturing material: metal and plastic. The installation of a plastic check valve is often made for ventilation, as it is less noisy.

Right choice

When choosing a device, it is necessary to take into account the speed of the air flow inside the vanescanal of natural traction. It is important that the valve blades are even weak streams. Since for natural ventilation, weak thrust is a common phenomenon, the fan with the check valve is often mounted in it. It is also important to have an idea how to choose the right fan: its power is chosen on the basis of the room area. To calculate the effectiveness of the air exchange of each room, different indicators are taken into account.

To select the correct ventilation valve, you should pay attention to the temperature of the external environment. When installing on a channel, leading through the wall to the street, it is recommended to use the "blinds" type valve, since other species are not resistant to low temperatures. The price when choosing a device is not determined, since it depends on factors such as the type of section, the size of the structure, the material of manufacture, etc.

In addition, when choosing a suitable device, it is necessary to take into account the method of its installation. Thus, the single-handed check valve on the ventilation of the gravitational action is set strictly horizontally or vertically, while the butterfly valve can be installed at any angle.

Homemade check valve

The manufacture of the homemade exhaust shutter is relevant in cases where Ventkane or non-standard form or sizes. The homemade design will cost cheaper than the adjusting duct box under standard sizes. If natural ventilation is functioning in the house, the check valve is better to make a membrane or single-type type of hard material. Before making the check valve, it is worth paying attention to such nuances:

• The plate must be tightly adjacent to the walls of the device's housing so as not to be formed by the air passing.
• The knock plate should be excluded, especially if the direction of air flows is often changed in the air duct.

For the manufacture of blades, you can use a lavasan film, the diameter of which should exceed the hole of the ventilation pipe. In order for the film to be not deformed when reverse damage, you can attach the grid to which it will rely on. The simplest check valves are made of the grille, to which the film is glued from two sides.

How to install the device

Installation of the reverse 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 ventkalanal, on the walls of which the layout of its location is made. After that, on the placed points, the holes for fastening are drilled. Check valve is fixed by dowels. There should be large gaps between the case and the walls of the channel. The gaps should be filled with sealant.

Installation of the valve for exhaust ventilation protects the room at home or apartments from the oppressive penetration of contaminated air. In order for the installation of the device to contribute to a high-quality air outflow, the installation should be carried out in compliance with the basic rules: the membrane correspondence to the diameter of the screw hole, its dense adjacent to the grille, and carefully sealed gaps between the device body and the air duct box.

Reverse thrust occurs quite often and carries negative consequences. Installation of check valve For natural ventilation, this question solves. But for this you need to explore the design features of such devices, their advantages and disadvantages, the basic rules for installation and placement in exhaust structures.

The main factors of the appearance of the reverse thrust

Operating principle supply-exhaust ventilation It is based on the action of the law of the same air flow and coming out of the room. Consequently, in the hood reverse thrust appears if the total air flow in other points is directed from the apartment. There are major factors for the appearance similar phenomena:

• Connecting neighbors in multi-factor houses of powerful hoods, When involving common ventilation mines to eliminate air. This problem is very common in old residential buildings, where total air ducts are not designed to use mechanisms for forced ventilation.
• Availability inside the house of the air duct, having several air intake points. In this case, changes in the flow direction are possible when the device forced ventilation is started in one of them.
• Sharp increase in streamwhich comes out through one of the exhaust deposits present. In case of insufficient air intake through supply ventilation, the direction of the air flow in extracts occurs.
• Significant reduction or suspension of flow, which enters the housing through the supply ventilation. This occurs in the case of phased contamination of the holes, and in the presence of a compulsory system - in case of damage or wear of parts, which are responsible for the movement of air.

Installation of ventilation check valve For natural ventilation during the installation of the system is a rational solution, even if there are currently no conditions for the appearance of the reverse thrust. The price of ready-made systems is small, but the valve installation in already functioning air ducts is not easy and time-consuming work.

Types of check valve

To date, the use of manual control to control air flow is no longer relevant. For automatic warning unwanted thrust in the ventilation system There are several fundamentally different ways. Each of them has their own advantages and disadvantages that need to pay attention to the purchase of equipment.

Single gravitational action

The air flow coming out of the room is capable of putting pressure on the valve flap, thereby opening it for free air outlet. In the absence of movement or reverse thrust This pressure on the damper does not occur and under the influence of gravity it closes.

If the installation was performed on all the rules, the inverse gravitational valve is permissible to use With natural ventilation, since it has minimal resistance to the opening of the sash. Two options are possible similar installation:

1. with a counterweight, which is located outside or inside the device;
2. deviation of axis accommodation on which the sash is attached, with respect to the middle of the section of the duct channel.

Note! The closing of the sash is based on the action of gravity, and therefore the device should be placed using a level strictly in a vertical or horizontal position, which depends on the specific model. Otherwise, incomplete valve closing Or to open the sash, a reinforced air flow will be required in the ventilation system.

Bivalve using springs

This is the so-called "butterfly" type device, equipped with 2 curtains. At an overpressure, they add up from a specific side, and in the case of its absence, it is closed at the expense of springs. Since the operation of the mechanism does not depend on the force of gravity, such a device is permissible to have a different angle.

This option has proven itself in the case of forced ventilation With the use of exhaust. Before buying a valve, it is worth tested the degree of sensitivity of the curtains to the pressure in the air duct, which will be installed. The strength of the springs in modern devices of this type is permissible to adjust.

Grid with a check valve for natural ventilation

In its appearance, the lattice with a check valve for natural ventilation is very similar to window blinds. This device has the principle of action similar single version - gravitational. The use of several sash instead of one is associated with the compactness of the mechanism in the open position, which is fairly relevant for the external components of the ventilation system.

The size of the ventlala with the check valve for Natural ventilation Designed for standard parameters of boxes designed for hoods. As for the device for preventing unwanted thrust, it is permissible to place both on the entire grille and only on the holes for natural ventilation.

Use flexible membrane

The working principle of the membrane check valve is based on the possibility of a stream to change the position of the flexible plate. It allows in the case of one direction air flow open vent hole, And in the opposite - it is close, closely adjacent to the perimeter.

In the case of the risk of changing the membrane due to powerful reverse thrust, the presence of auxiliary ribs of rigidity to which it can rely during closing the venting hole. It is worth paying attention to when buying a membrane mechanism, otherwise deformation and further loose closure of the flap or the passage of the return air flow is possible.

For all systems, regardless of the configuration, it is necessary calculate the location of the valve So that unwanted traction for all variations of the included hoods and fans as a result was blocked. The quality of the ventilation functioning primarily affects the correct installation of the device.

Valve location in the ventilation system

If the exhaust system provides a single air intake place, and it is located on the street or in the mine, to warn appearance of reverse traction It is enough to install in the air duct of one device.

If the system is complicated by the presence of multiple holes for natural ventilation, the following installation rules apply check valves:

• On all branches that combine the central air duct and the air intake point, the check valve mount. This is important to prevent airflow redirection towards the exhaust, if it does not work.
• As a rule, an additional device is mounted at the ventilation system output. In the case of the absolute tightness of the channel in the installation, there is no need, but still, as practice demonstrates, the presence of the valve is in this place it makes sense.

Ventilation check valve for natural ventilation

Basically, the check valve is placed in places with the most convenient and easy access to them. This is due to the fact that they are from time to time. brush from fat, puffed dirt and dust, Otherwise, there will be no complete closer closure with unwanted traction.
During the design of the air duct, it is important to remember that the manufacturer in some cases places check valve Directly on the exhaust or on the fan. In such a situation, the installation of additional protection against the appearance of reverse thrust is not required.