Check valve for household ventilation. Check valve for ventilation. Petal check valve and its features

The smells of neighboring apartments or houses are hardly very attractive, especially when fish is being fried or soup is boiling on the stove, or if heavy smokers live nearby. These and other unpleasant odors can come to us through the ventilation system.

This problem arises due to the passage of the ventilation duct of foreign odors during reverse thrust. The solution to this problem is quite simple - installing a check valve that prevents foreign odors from entering your apartment from the outside.

How is a non-return valve arranged and how does it work?

The non-return ventilation valve, regardless of its type and size, is a shutter, the opening of which is carried out by air flow in only one direction. During a change in airflow direction, the shutter closes, preventing air from going in the wrong direction.

For air ducts, check valves in the form of a disc (round) are usually used, much less often - rectangular.

A check valve is often installed even when there are no conditions predisposing to reverse thrust.

Purpose

The main purpose is to protect against draft overturning (so that the air through the ventilation system goes only in the direction that is required in this area, and cannot go in another). The device is designed for both supply and exhaust air ducts.

A check valve can be useful under the following conditions:

1. Insufficient supply air (for example, there is no supply ventilation, or it is clogged and does not work).
2. The presence of several exhaust openings in the room at once, with an increase in draft in one of them (for example, intensive operation of one fan when others are inoperable).
3. Strong draft in the chimney during fuel combustion, with the formation of a reverse air flow in the channel with natural ventilation.
4. Incorrectly installed exhaust pipes on the roof of the building (in the so-called wind shadow zone).
5. Strong hood in an apartment located in a multi-storey building.
6. It makes sense to install a non-return valve in winter for rooms where ventilation is turned off during frosts (including to protect against carbon monoxide poisoning).

Where can it be installed?

A reasonable question arises as to where this product can be placed. In fact, it is used in many types of premises and in various sections of the duct. It can be installed not only in apartments and private houses, but also in industrial and commercial premises.

You can install the device in the following systems:

• in natural ventilation systems;
• in forced supply and exhaust systems.

It is advisable to use the device in the following buildings-premises:

• in private and multi-apartment buildings;
• at various enterprises (industrial premises);
• for the kitchen and toilet, if they have hoods (in this case, the valve is placed on the opening of the ventilation shaft, and does not allow the hood to blow air back into the room).

Classification

There are several varieties of this device, which differ in several ways.

Varieties along the axis of rotation of the shutter:

1. Horizontal view.
2. Vertical view.

Varieties according to the material of manufacture:

• metal, made of galvanized steel (they are used much less often than plastic ones, because, despite their strength, they are prone to rust, condensation and make too loud sounds during operation);
• plastic (devoid of the shortcomings of metal analogues).

Varieties by scope:

1. Heated (for conditions where the appliance will be in contact with warm and cold air alternately, which can lead to frost formation).
2. Without heating (for rooms and systems where there is no possibility of freezing).

Check valve types according to product structure:

• single leaf;
• bivalve (the so-called butterfly or petal type);
• membrane;
• "blinds".

Varieties in shape (for ventilation ducts of different sections):

1. Rectangular.
2. Round (in the form of disks).

Where is it sold and how much does it cost?

You can buy a non-return valve in ventilation products and equipment stores. The cost depends on what type of valve and what size you need.

Approximate cost of various models:

• model VENTS KOM 125 mm - 290 rubles;
• VENTS KOM 100 mm - 250 rubles;
• VENTS KOM 150 mm - 290 rubles;
• VENTS KOM 200 mm - 320 rubles;
• VENTS KOM 315 mm - 550 rubles;
• VENTS KOM 1600x350 mm - 2500 rubles;
• VENTS GFK (gravity for a tee) 160 mm - 830 rubles;
• VENTS KOM 250 mm - 420 rubles;
• VENTS GFK (gravity) 140 mm - 760 rubles;
• VENTS KOM (rectangular) 1400x200 mm - 2010 rubles.

Do-it-yourself check valve for ventilation (video)

How to choose?

You need to choose the right check valve, paying attention to the characteristics of your ventilation equipment and choosing a model with the appropriate parameters.

The first step is to think about the ambient temperature at the place of operation of the product. Also, think about the rate at which blockages appear, as frequent blockages are common in ventilation operations in conditions of regular high winds (usually in open areas).

Even such data is already enough for a more or less competent selection of a product. When operating conditions are too cold, it is better not to use the butterfly valve, as it will simply freeze. But the problem with frequent blockages cannot be solved - valves of any type become dirty equally quickly.

You also need to think about which fan is installed, for which the valve will be mounted (if we are talking about a forced ventilation system). If the hood works too poorly (with low draft), then the check valve will simply become a duct damper, but it will not perform its main function.

It is necessary to select a fan with such power that it corresponds to the operating conditions. For example, for the kitchen, you need to take into account the value of the coefficient 10, and for the bathroom - 7. Do not be afraid to buy an additional exhaust fan to increase traction.

Installation rules

When the ventilation system has only one air intake point, through which it enters the mine or the environment (on the street, for example), it is enough to install one valve. But if the circuit is somewhat more complex, you will have to mount several valves at different points.

The second case requires compliance with the following installation rules:

1. A separate valve should be installed for each branch of the air intake stack and main duct. This is necessary to prevent the redirection of the air flow towards the hood when it is turned off.
2. It is recommended to install another valve at the ventilation outlet. This is not necessary if the channel is completely sealed (but even in this case it is recommended to install an additional device).

It is important to mount the device in places where it will not be difficult to get to. Dust and grease contamination is common, so the product will need to be cleaned regularly.

When choosing equipment (hood, fan), always keep in mind that the manufacturer could already have installed a non-return valve in advance. Then you do not need to install an additional device.

Household ventilation should be equipped using round or rectangular air ducts with basic parameters (dimensions). If there is a need for alternating operation of forced (fans) and natural ventilation systems, then two methods of fastening the check valve can be used:

1. Installing a tee directly after the ventilation grill, with mounting the valve on the branches to ensure natural ventilation (as in the photo above).
2. Acquisition and fixing of a grate with 2 holes for both types of ventilation (for example, there are grate slots for natural ventilation below, and above them a round hole for connecting an exhaust duct). But it is better to use the first method.

How to do it yourself?

If you decide to save money, or cannot find a suitable model, you can try to make the valve yourself.

You will need the following materials:

• lavsan tape (as much as possible);
• tee with a cover in diameter;
• a self-tapping screw with a spring that matches its diameter (it can fit on it);
• film or flexible plastic;
• long line;
• stationery knife.

The film must meet the following criteria:

1. Its dimensions should be slightly larger than the outlet (hole) of the ventilation duct.
2. When choosing a film, one should be guided by the fact that the thickness directly depends on the parameters (in terms of dimensions) of the cells - the larger they are, the thicker they are, respectively.
3. Do not use film with a rough surface.
4. Crumpled material is not suitable for the manufacture of the membrane.

Manufacturing instructions (also available in the diagram-image with details above):

1. First of all, we draw the markings on the grid. According to this drawing, we will mount the future halves of the membrane.
2. Using adhesive tape, we fix a film (but not yet cut) on a large-sized grill. Please note that the tape should not be stretched when attaching.
3. Next, with the help of a knife, we cut out the outline of future sashes (we make right and left outlines, like shutters on windows).
4. The final design must be airtight. You can check this as follows: when closed, the membrane should normally completely cover the lattice holes and at the same time there should be no various defects in the form of irregularities.
5. Be sure to glue the sash fasteners as carefully as possible.

If everything is done correctly, a home-made version will be no worse than a purchased one.

In multi-storey buildings, sometimes there is a problem of unpleasant odors from natural ventilation channels. They appear when the ventilation system does not work properly, when the exhaust air is not thrown out, but returns from one room to another. One way to solve the problem is a non-return valve for natural ventilation installed on the outlet from the ventilation duct. This situation occurs not only in houses and apartments, but also in all buildings with a gravitational ventilation system.

Ventilation systems for all types of buildings are divided into two groups:

• with natural motivation (gravitational);
• with artificial motivation (mechanical).

They differ in the mechanism of setting air in motion. Natural systems consist of structural elements:

• external windows, doors and other openings in building envelopes;
• ventilation shafts (ducts).

To organize a mechanical system, fans, an air duct system and other components are used. It is more convenient to set up and allows you to control the parameters of air exchange, but it is much more expensive than natural. Most apartments and residential buildings use gravity ventilation. For her, vertical ventilation shafts and tie-ins are arranged on each floor of the outlet to the premises. What types of non-return valves for natural ventilation are there and how are they used?

The principle of operation and types of check valves

The non-return valve for mechanical systems and natural ventilation belongs to the group of air dampers and regulators designed to change and shut off the air movement in supply and exhaust systems. If the device accepts only the "open" or "closed" positions, then it is considered to be on-off. In multi-position products during operation, the air damper takes several positions (with different throughput). Check valves are used to move air in only one direction and are two-position devices.

Structurally, check valves are available in the following types:

• petal;
• with a gravity grid.

Models with a gravity grate are installed at the end of a branch of the ventilation system. For example, at the exit from the exhaust network to the street. They are lattices in which the blinds are freely raised by air pressure and lowered by gravity. Such check valves are used only when air moves in a horizontal position.

In a natural ventilation system, such a product is not applicable, due to the peculiarities of its functioning. If you install it at the outlet of the ventilation shaft, then the pressure of the flow of air naturally rising through the channel rarely reaches such a value that the blinds on the grille can lift.

Valves of the second type consist of a body and petals that completely block the channel section when the air flow moves not in the design direction. They are conditionally divided into two groups - single-petal and two-petal ("butterfly" type).

In check valves of the first type, the petal, which blocks the movement of air, is freely fixed on the axis in the section of the product. The position of the petal depends on the angle of inclination of the valve and the air pressure. In a disconnected system, they can be in both open and closed positions, and when air moves in the right direction, the flow area increases in proportion to pressure.

Products with two petals are equipped with a spring retainer or counterweight. In the absence of air movement, the device is completely blocked. They are used in a vertical and horizontal position, unlike single-lobe, which, with the calculated movement of air from top to bottom, cannot be installed in the closed position when the system is stopped. All types of valves are produced for both rectangular and round ducts. The maximum speed of movement in the section of the check valve is 12 m/s.

Due to technical and structural features, double-leaf valves with a spring are not applicable in natural ventilation systems, since the pressure in them is not enough to open. Single-lobe devices work effectively as check valves in the natural ventilation system. Consider the application scheme.

Use in natural ventilation

A non-return valve for natural ventilation is used in a system using one channel for connecting a mechanical device (for example, a kitchen hood) and a grate. When there is a reverse draft from the street in a natural system, the valves are not effective due to the low air velocity. The same applies to the problem of unpleasant odors from neighboring kitchens.

Mechanical fans and cooker hoods may not always be connected to common house ventilation ducts. In some series of multi-storey buildings, taps on several floors are connected to one shaft, and when a fan cuts into it, the pressure increases so that the air leaves the channel not only outside, but also into neighboring rooms. But if the air duct leads out of the apartment without branches, then such structures are allowed.

Even if only one ventilation duct comes out of the kitchen, bathroom, or other room, it can be used for both natural and mechanical exhaust by installing a check valve. For example, the photo shows a diagram for a kitchen hood.

When using locking and regulating devices, do not forget that they are clogged with dirt, dust and grease. Check valves need regular cleaning and inspection to function properly.

Do the smells of cooking food return again, instead of leaving the premises forever? Agree, this is an extremely unpleasant situation, which you want to get rid of as soon as possible. Most likely the problem lies in the occurrence of reverse thrust. This is a common phenomenon that has many negative consequences.

We will help you get rid of unwanted odors with a simple and inexpensive tool. It will not require redevelopment of existing ventilation ducts or significant financial investments. It will be enough to install a check valve on the ventilation, which will solve the problem.

For an optimal result, it is necessary to know the design options for the valves, their pros and cons, as well as the rules for placement and installation in exhaust systems. All information is given in our article. It also contains useful videos with step-by-step installation instructions and photos that demonstrate the essence of the material presented.

In order to decide on the installation of a check valve, it is necessary to find out the possibility of back draft in the ventilation system of the house. Understanding this process will allow you to properly plan and implement air exchange in the premises.

Are you satisfied with the ventilation in your apartment? If you answered the question in the affirmative, then everything in your house was done by real experts, without flaws. But this is not always the case: very often ventilation shafts have irregularities on the inner surface or narrowing of the cross section. All this as a whole leads to the fact that the air flow can enter the apartment when the fan is off.

This phenomenon very often also occurs due to clogging of ventilation. The flow of air entering the general ventilation from the lower floors easily fills the apartments of the residents of the upper floors. This happens only when the fan in your apartment is turned off. So what happens? Keep the fan on all the time?

In this case, the energy consumption is too high, and the device will fail prematurely. The installation of a check valve will save the situation. Such a simple device will not increase the ventilation in the apartment, but it will provide a barrier to the air flow into your apartment.

Check valve types

There are two types of check valves: with vertical and horizontal dampers. The choice of a certain option should be made depending on the direction of movement of the main air flow in the ventilation shaft. The next important point is the material from which the dampers (curtains) of the check valve are made. Metal structures seem to be more reliable.

They are more durable, self-closing under the influence of their own gravity. The disadvantages include only the reaction of the metal to the impact of an aggressive environment. Galvanized (or otherwise treated) dampers will not corrode, but condensation will certainly collect on them.

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check valve design

The design of the check valve can be any. Ventilation options with butterfly curtains are the most popular among consumers. Such a unit works very simply: inside the valve body there is a vertical axis on which two curtains are located. When overpressure is created from the forced ventilation side, the shutters fold in and open access to the ventilation well.

When the fan is turned off, the curtains return to their original position due to the spring or counterweight. Such a valve for ventilation requires careful adjustment, since it can only block the air flow with a rather impressive effort from natural ventilation. As a rule, the non-return valve is not adjustable, so when choosing a product, you must immediately pay attention to its sensitivity.

Interesting is the design of the valve with a horizontal arrangement of shutters. In the normal position, all curtains are vertical. Loops are located at the top of each curtain. Curtains under the influence of their own weight tend to the ground and block the air flow. When the fan for forced ventilation is turned on, the curtains under the influence of pressure take a horizontal position and open the air flow.

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How to make a valve with your own hands?

Is it necessary to buy a ready-made check valve? You will have to solve this issue yourself. As you may have guessed, almost any man can make such a check valve. It makes no sense to make more complex designs on your own, for the reason that it will take a lot of time and the costs will be disproportionately higher than when buying a finished product. The price difference for valves is quite noticeable. The simplest designs are ten times cheaper than more complex counterparts.

By the way, expensive non-return valves are not available in retail trade, as they are sold complete with fans.

This makes a lot of sense: the design of the damper is calculated for a specific fan model, so it will work perfectly in tandem with this fan. In another set, a mismatch can greatly affect the operation of one of the devices.

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Tools and materials for installation

The check valve for ventilation is easy to install. You only need to have:

• check valve;
• assembly instructions;
• screwdriver (you can limit yourself to ordinary screwdrivers);
• self-tapping screws;
• sealant (or silicone).

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Phased work

First you have to dismantle the fan that you have successfully used. We install the non-return valve body in the ventilation hole and make marks on the places of the intended fasteners. The case is to be removed, and on the resulting marks you need to drill holes.

We return the case to its original place and through the holes we make marks on the walls of the well for ventilation. We remove the valve again, and holes will have to be made on the marks obtained. You definitely won’t be able to use a puncher, so you have to use a jumper (a device for making holes in concrete bases mechanically).

We hammer dowels of the appropriate size into the holes. It remains only to return the check valve to its place and wrap all the fasteners until they stop. Pay attention to the resulting holes or gaps between the check valve body and the ventilation well. If their size is visible to the naked eye, then the installation of the check valve will have to be supplemented with sealing. The simplest thing is to silicone all the gaps.

This moment cannot be ignored, since the air draft will not be sufficient to close the valve shutters. This will not harm ventilation, but the valve will either not perform its main function, or will not be fully. After completing all the described work, it is necessary to install the fan in its original place. On this, we can consider the mission accomplished: the ventilation will work reliably, the check valve will not let foreign odors into your house.

Currently, non-return valves have begun to appear on sale, which do not imply such drastic changes. Such devices are not mounted behind the fan, but directly in front of it. Such peculiar valves are overhead. They work no worse than previously described. The only peculiarity is that the valve will protrude somewhat above the plane of the wall. With a well-designed case, this can be the easiest solution to ventilation problems, and will give this device a certain charm to the design of the room.

Residents of apartments in multi-storey buildings are often faced with the fact that smells from neighbors through the ventilation ducts enter their premises. An unpleasant situation that the check valve for ventilation will help to cope with. How it looks, how it is arranged and where to put it, and we will discuss.

Why do you need a non-return valve for ventilation

During normal operation of the exhaust ventilation, air moves from the room to the street. Exhaust openings are located "in dirty or damp" rooms - a bathroom, a kitchen. The task of this part of the ventilation system is to remove odors and excessive moisture to the street. But sometimes a situation arises when air goes in the opposite direction through the exhaust ventilation - it enters the premises. This moment is called thrust overturning and they try to fight this phenomenon.

Why fight backlash? In the case of apartments, this is fraught with odors from neighbors, which is very unpleasant. If we consider private houses, portions of outside air in them reduce the temperature in winter. The second point is more dangerous and unpleasant - with reverse draft, the boiler may go out, combustion products (and carbon monoxide too) can return to the room from the chimney. In any case, the reverse movement of the air flow is an incorrect operation of the ventilation system and this phenomenon must be fought. The check valve for ventilation is just set to block the movement of air in the wrong direction.

Device and principle of operation

The check valve for ventilation is most often a piece of round or square pipe. In this segment, a piece of material (metal, plastic, mica) of a suitable shape is movably - usually on an axis - installed. This is the valve itself. In the closed state, it completely covers the pipe section, in the open state it should create as little resistance as possible. In order for everything to work correctly, it is necessary to set it so that when a reverse air flow occurs, the valve closes.

They put not only valves in the pipe for ventilation - there are options for a ventilation grill and a fan. In the case of a ventilation grill, a thin plastic or mica membrane can be used that is attached to the grill. There is also a butterfly valve and slats such as blinds. The same type of air return valve can be installed on the exhaust fan.

The principle of operation of this device is simple: during normal air movement, the valve is open and creates a slight resistance to air flow. When a reverse draft occurs, it closes, preventing the entry of foreign odors or cold air from the street into the room.

Troubles that may arise

Everything seems to be clear and logical: extraneous smells in the apartment are very unpleasant. Traction overturning in a private house is no less unpleasant, but also dangerous. In principle, with a properly calculated system, such phenomena should not occur, and the causes of occurrence must be dealt with. But not everyone has the opportunity and resources. It is easier to put a check valve for ventilation. This is true, but there are nuances that are worth knowing.

As you can see, putting a check valve on ventilation does not mean solving the problem once and for all. You will have to monitor the state of the system and put up with the shortcomings of this solution.

Kinds

The check valve for ventilation can be made of metal or plastic. Metal is most often galvanized, less often stainless steel. There is also a small group with a plastic case and a metal damper - most often called a “combined non-return valve for ventilation”.

How to choose on this basis? Just. Choose the material from which your air duct is made. They can be round or square models. Here again, we choose the same form as the existing / planned ones. Fortunately, the dimensions correspond to standard pipes used for air ducts.

Opening method

Check valves can open in different ways:

• Manual. The dampers are opened or closed manually, for this they have a special lever. This is not very convenient, in addition, due to the design features, they are not tight, so they cannot completely block the penetration of foreign odors.
• Electric. Forced to open simultaneously with turning on the fan or hood. Suitable only for ventilation systems with forced air removal (without natural circulation).
• Mechanical. The most common type. Open and close against air movement. They are placed both in tandem with a fan or extractor hood, and for natural ventilation.

A manual non-return valve can be placed on a forced air vent pipe to the outside. This is sometimes done - they are not taken out into the ventilation duct, but out into the street through the wall. In this case, it is better to have a damper that will open only while the hood is running. You can, of course, put a normally closed valve, but in cold weather it will freeze and stop performing its functions. Therefore, manual opening is more reliable in this case.

The most common are mechanical check valves. They are installed in about 90% of cases. Structurally, they can be of different types. Here we will talk about them in more detail.

Shapes of mechanical valves

Different flaps can be installed in the check valve. The force at which it will move away largely depends on the shape of the damper. If the damper is to be operated with a fan or exhaust hood, it is important that the weakest fan setting can open the damper. They say that the fan should push through the valve. If you want to maintain natural ventilation, it is necessary that the damper can "work" even from a slight movement of air.

The designs and forms of mechanical check valves for ventilation ducts can be as follows:

Choosing a valve for ventilation is really not easy. If you are guided by what the majority uses, you will have to stop at the clapperboard. With all its shortcomings, it works more reliably, opens even with natural ventilation. The most effective way to make the cracker quieter is to take silicone sealant, apply it to the thrust ring on the body (do not apply to the disk, as it will become heavier, which means it will be more difficult to turn). Lubricate the valve disc with soapy water and press it against the sealant ring - until polymerization begins. Then we move the valve aside, we get an o-ring that dampens the pops. The result is an almost silent closure, and almost hermetic.

Valve for ventilation: where and how to put

If made without the use of fans and hoods with motors, it is called natural. To make everything work, to block the reverse thrust, valves are installed immediately at the outlet of the channels. To maintain normal circulation, it is advisable not to use grids that block the valve. Yes, this option looks better, but ventilation suffers. Most likely, it simply will not work with a small thrust.

If you still want to install in front of the valve, you will have to put up with poor ventilation, slower odor removal and excessive moisture. Only the installation of a grate / valve of a larger diameter than calculated can help. In this case, air exchange will not be affected.

In the case of forced ventilation, the check valve can be either before or after the fan. This choice depends on the type of system and fan. Since duct models of fans are rarely used in private systems, it usually turns out that the damper is after the fan in the pipe. How far is not important. The main criterion for choosing an installation site is ease of maintenance, since the damper will have to be cleaned and checked periodically.

Installation in a kitchen with a hood

When installing a forced exhaust hood in the kitchen, many people want to maintain natural ventilation as well. To do this, you will need to install a tee at the inlet to the ventilation duct. Connect an exhaust hood with a non-return valve to one of its inlets, put only a non-return valve in the second. As you can see, the system is not too complicated, but it works.

How to connect the hood so that natural ventilation remains

Why does the hood also need to have a non-return valve? Because if it is not there, the reverse air flow can pass through the hood. Yes, it will not happen every time, but with a strong flow, it will.

When installing this unit, try to make sure that the check valve for ventilation is located as high as possible under the ceiling. As a result, the warmest and most humid part of the air will be removed, which is very important for the kitchen.

For bathroom and toilet

Bathroom ventilation can have its own exhaust duct - then everything is easy, simple and understandable. Before entering the ventilation duct, we put a check valve to block the flow of air that will move into the room. But not all apartments can boast of individual shafts for the bathroom and toilet. In some houses of the old layout, there is an exhaust duct only in the toilet. Bathroom ventilation is done by passing the box through the wall. In this case, we put a non-return valve for ventilation not only at the outlet to the ventilation duct, but also in the channel between the bathroom and the toilet. This will prevent bad odors from entering the bathroom.

There is an even sadder situation: when there is only one exhaust duct and it is in the kitchen. Actually, the installation logic does not change - you need to install the devices so that smells from one room do not get into another.

One check valve for ventilation is placed on the outlet to the dome hood (or on the channel that removes air from the kitchen), the second - on the pipe that goes from the bathroom. As you can see, if you understand the logic of work, you can determine the most successful installation location yourself.