
2023 Author: Philip Bishop | [email protected]. Last modified: 2023-05-24 22:24
- What is a check valve for?
- Types of check valves for ventilation
- How to choose the right check valve
- Device Installation Recommendations
- How to make a check valve with your own hands
The ventilation system of the room is designed to provide fresh air flow, while removing waste, unpleasant odors and dust. It often happens that the ventilation installed in a multi-storey building does not cope with its tasks, and instead of clean air, extraneous odors from neighbors enter the apartment. To prevent this from happening, it is recommended to install a non-return valve for ventilation.
What is a check valve for?

A check valve is a design in which the blades of the valve itself, located on the axis, will move in such a way that the air entering the valve will not enter the apartment. Air masses in the check valve move in only one direction, and if it changes abruptly, the device closes, which prevents air from entering the room.
The main reasons for installing a check valve are:
- Lack of supply ventilation - it can be broken or clogged, and therefore the supply air simply does not enter the ventilation.
- Incorrect location of the exhaust pipe, as a result of the ingress of blown air into the ventilation.
- Stove heating is installed in the house, and when the stove is operating, the combustion draft increases in the chimney, which contributes to the return flow of air in the ventilation pipe.
- A powerful hood is installed in one of the apartments of a multi-storey building, and during its operation, the air flow in other apartments is disrupted.
- The presence of several hoods in one apartment will increase traction in one of them, which will lead to a violation of the outflow of air.
You can use a candle to check for draft in ventilation. Bring a lit candle in the ventilation and open the window. If the air flow is correct, the candle will go out.
Types of check valves for ventilation
Valves for ventilation can be classified according to the material of manufacture, most often they are made from:
- Plastic.
- Fine galvanized steel.
- Combined materials - steel and plastic.

A version made of plastic is often installed in apartments, offices, cottages. These check valves have an attractive appearance and will suit any interior style. In addition, the plastic valves can easily cope with natural ventilation tasks. Another undoubted advantage of them is their availability - plastic check valves are the cheapest devices among other analogues.
Models made of galvanized steel are used in industrial enterprises or in office buildings for household purposes. These valves have a robust design that allows them to function in supply and exhaust ventilation systems. In addition, enterprises always put forward increased requirements for fire safety, and steel valves do a good job with this task.
In buildings where natural ventilation is present, devices made of combined materials have proven themselves well. The body of the product is made of galvanized steel and the blades are made of plastic. Thus, the valve reacts to the smallest wind and ensures natural air exchange.
Depending on the design, ventilation check valves are:
- Petal. They are made in the form of a rigid damper, fixed on an axle, and contain the principle of operation of the rotary mechanism. With the flow of air masses, this damper rotates, thus closing or opening the air inlet.
- With gravity grid. Outwardly, they resemble blinds located vertically or horizontally. When the hood is turned on, the flaps open and begin their work. This type is installed in walls to protect communications.
- Membrane. They work on the principle of petal valves, however, the damper in such devices is much thinner, and when the wind blows, the membrane closes the grate, thereby preventing air from entering.
- Butterfly Similar in structure to the petal-type valve, however, it has two petals on the axis, which resembles the famous insect. When the ventilation is turned on, the petals open and, accordingly, when turned off, they close.

In addition, valves are available in horizontal and vertical types, with or without heating, and rectangular or round.

How to choose the right check valve
When choosing a check valve for your apartment, you must be guided by the following criteria:
- The appliance must be sensitive to even small air movements, therefore it is better to install an exhaust fan with a grill. This will promote normal air exchange and increase traction.
- The technical indicators of the valve must correspond to the purchased fan: the power of the latter must ensure full opening of the valve petals. Select the valve diameter to match the exact size of the fan.
- Pay attention to the operating temperature of the valve - some devices can only operate at medium temperatures.
- Depending on the shape of the duct, a suitable check valve with the same shape is selected. This is done for the convenience of installing the device.
Do not forget that if the valve is incorrectly selected, air exchange in the apartment can be disrupted and completely change its direction.
Device Installation Recommendations
When installing the valve in ventilation yourself, it is important to remember the direction of the air masses. If this issue is resolved, then you can proceed to the direct installation of the device.
To do this, insert the valve body into the ventilation duct and mark the holes for future fasteners. After that, drill holes at the designated points using a screwdriver or drill. It is also necessary to make holes for fastening in the ventilation.
Then insert the dowels and fix the non-return valve in the ventilation with a screwdriver. It is important to pay attention to the gaps between the valve and the ventilation: if they are too wide, they must be covered with silicone to ensure tightness. If this is not done, then the device will not be able to perform the intended function.

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How to make a check valve with your own hands
Having figured out the principle of the check valve, you can easily make it yourself at home. The simplest will be a membrane-acting valve. It will require a ready-made grid, a polymer film of medium thickness, adhesive sealant, fasteners.
The manufacturing process consists of the sequential execution of the algorithm of actions:
- Measure the dimensions of the ventilation opening and cut the grille so that its dimensions are 2 cm larger than the ventilation outlet itself.
- If there is a piece of plastic for the workpiece, then use a file to make the grid.
- The surface of the grid must be smooth so that the membranes fit snugly against it.
- Attach two squares of 0.5 mm thick foil on both sides of the grate. It is better to do this with a sealant.
- Drill holes in the grille for wall fixing.
- Place the grill in the vent and secure.
A self-made device will be able to work both with a natural ventilation system and with forced air circulation.
If there are problems with ventilation, it is still recommended to install a non-return valve, thus ensuring yourself comfort and the absence of unpleasant odors in the apartment.
