As you know, the air in the ventilation ducts can move in both directions, which causes certain problems, because cold winter air can penetrate the room, as well as dust. That is why such a node as a non-return valve for ventilation should be present in the system - almost anyone can put it with their own hands.
Thanks to him, the air moves only in one direction, with the possibility of opening the valve only during operation of the fan or exhaust, which is very convenient.
Types of devices
There are several variations of the considered type of valves, but only some of them are widely used, we will consider their features in more detail:
|Swivel type mechanism||The simplest option, which is a block of round or rectangular section, in which a valve is located on the axis, which works thanks to the system of weights and counterweights. Control of such a device can be carried out both manually and in an automated way; it is possible either to completely block the flow or to regulate its intensity.|
|Butterfly valve for ventilation||This type of construction has the following device: on the axis, located in the housing, two petals are fixed, which open when the fan is turned on and close when it stops working. A simple mechanism is used very widely in the finished units, including the fan and the valve.|
|Flap valve for ventilation||The system is a series of horizontal or vertically positioned louvers that open when forced ventilation is turned on. Provide high-quality protection of communications and are most often installed at the outlet openings located in the walls|
Criteria for device selection
In order for ventilation with a check valve to work efficiently, it is necessary to take into account a number of factors and select products with optimal technical characteristics, this is important, since any errors can create many problems.
What to look for when buying
The correct valve selection is a guarantee of the absence of failures in the air exchange system and the provision of optimal conditions for the functioning of all communications.
The most important factors are the following:
- Estimated air velocity in the system, the safety device must open even with minimal movement of air masses. This is especially true for natural ventilation systems, where the thrust is very small, and sometimes the only possible option to ensure operation is a ventilation grate with a non-return valve and exhaust fans, this simple device will provide the desired draft.
- It is very important that the check valve for ventilation in an apartment or house is suitable for the characteristics of the fan. The easiest way is to buy both of these products in the same package, this ensures the correct functioning of the system. But if the units are purchased separately, then the thrust generated by the fan should ensure the opening of the valve.
- Another important factor is the climatic features of your region. For example, butterfly-type devices are prone to freezing during long-term negative temperatures, so they are best installed indoors, rather than on the output grilles. This will avoid freezing and jamming of the nodes.
Tip! In some rooms, the ventilation pipelines may eventually become clogged and covered with bloom, if you have a valve without an electric drive, even a small layer of plaque disrupts the balance of the device and causes it to malfunction, so remember to periodically monitor and clean the petals.
- It is also important to take into account the characteristics of the system installed in the room. If the ventilation box is rectangular, then the valve body should be the same, it will greatly simplify the installation work, otherwise you will have to make a self-made adapter. The size of communications is also important (most often pipelines are 100 by 100, but there may be other options).
Tip! It is best to purchase products of well-known companies that have proven themselves in the market. This ensures the quality of the product and its compliance with the stated parameters.
Some design features
There are a number of nuances that you should know when choosing a specific option:
- By the method of installation, devices of horizontal and vertical type can be distinguished. The first are installed on horizontal sections, the opening direction is chosen in accordance with the system, the second option is placed on the risers, and the direction of air in it is always from the bottom up.
- If you install a check valve, you should select a product with a convenient fastening system, it is best if this is an option with flanges or clamps
- Another important nuance is the installation location of the structure; if it is located in or near the outer wall, it is better to purchase an electrically heated version, this will prevent the blades from freezing at negative temperatures and prevent condensation in the system. If the valve is installed from the inside, then this option is not required.
A non-return valve in ventilation systems prevents the entry of cold air and dust into the room, allowing you to maintain an optimal microclimate.
The video in this article will help to better understand the features of the type of devices in question.