Ventilation grille with check valve: device and types + installation recommendations

Sometimes ventilation not only removes exhaust air outside, but also becomes a source of unpleasant odors.This happens as a result of the entry of air masses from adjacent rooms or from the outside due to the occurrence of reverse draft.

To solve this problem, a ventilation grille with a non-return valve was invented, blocking air flows trying to enter the room. In this article we will get acquainted with the design features of such a grid, its main advantages and reasons for use.

We will also analyze the process of self-installation and the rules of operation of this device.

Design and advantages of a grille with a valve

The model includes three main parts: fixed, movable, flange for connection air duct.

The stationary part is the grille itself. It acts both as a decorative element and as a barrier that protects and closes the valve from accidental damage.

Since the grille closes the ventilation hole, smell and all kinds of small particles do not penetrate from the street. When the outside temperature drops, the grille prevents heat loss

It has a rectangular geometry and is made of plastic. The structure should cover not only the ventilation shaft, but also cover a little of the wall.

The mobile part visually looks like a petal, round or rectangular, although sometimes you can find an unusual shape - a “butterfly”. It only opens in one direction.

The valve for gratings is made of plastic, since it has to be used in conditions of aggressive moisture.

The flange in cross-section looks like a circle. Its diameter is from 11 to 15 cm. The valve is integrated into the air duct using a flange

This ventilation grill has a number of advantages:

1. It will protect from both cold and too warm street air.
2. No insects or dust will enter the room.
3. The room will be protected from foreign odors.
4. The presence of a noise-absorbing effect will prevent the penetration of extraneous sounds.
5. Easy installation and maintenance.
6. Aesthetic appearance of the decorative grille.

The main disadvantage is that if the temperature is below zero, the blinds or petals may freeze. To solve this problem, a heater is built into the system.

When is a grille with a check valve needed?

The advisability of installing a grille with a check valve is due to the presence in the ventilation system reverse thrust.

Therefore, if this phenomenon is absent, there is no urgent need for it, but for prevention it is still worth installing a grille.

A high-quality valve shutter should be so sensitive that it can quickly respond even to weak air movement

The following factors can cause backdraft:

1. Lack of air flow into the room or reduction in its volume.
2. Debris getting into the hole.
3. Failure of elements that control air flow.
4. Operation of high power hoods.
5. The wind that was not taken into account when designing the house was constantly blowing.
6. The presence of several pieces of equipment in the ventilation system, the air outflow operating simultaneously.

All these circumstances create conditions for the appearance of reverse thrust. In this case, pure oxygen does not enter the room. There is no guarantee that at least one of the listed factors will not appear. It is better to protect your ventilation system by installing a grille with a check valve.

Existing varieties of such gratings

There is a classification of ventilation grilles equipped with a valve.

Depending on the type of locking device, they are:

• gravity single-leaf;
• petal;
• membrane;
• butterfly

Ventilation grilles are made of plastic and galvanized metal.

Nowadays, ventilation grilles with a check valve are very popular. With their help, air flows are controlled. Such products are often used in bathrooms and toilets.

The former cannot tolerate sub-zero temperatures, so they are mainly used for indoor installation. They have light weight, high corrosion resistance, long service life, and low price.

Metal grilles are usually installed outside. To prevent them from freezing in winter, heating is used. The shape of the gratings can be rectangular or round.

They are characterized by high heat resistance, so they are used for installation in hot shops, large kitchens, and outside buildings. The big disadvantage of these products is their susceptibility to corrosion and heavy weight.

Type #1 - single-leaf gravity grille

This model has an extremely simple design. The locking element here has the shape of a circle or rectangle. It is a structure with a locking mechanism eccentrically fixed to the axis.

The work is based on the fact that the air flow, having the correct direction, moves the damper and then moves freely along the air duct. An air avalanche of reverse direction pulls the valve to the frame of the grille and closes it.

The working leaf of the gravity single-leaf grille opens under the influence of the pressure of air masses coming from the room. The advantage of the design is that it works automatically

There are two versions of such models - with a displaced damper mounting axis relative to the axis of the air duct pipe and with a counterweight located outside or inside the device.

The device is installed strictly vertically or horizontally. Otherwise, the damper will not close completely and will not provide adequate protection of the room from the outside atmosphere.

Type #2 - membrane type of device

This type of grating is the most common. Here, a light and flexible membrane acts as a sash. Since it has little resistance, it closes under the influence of gravity.

Due to its simplicity and reliability, the model is used in ventilation systemswhere air flow circulates naturally.

There are no mechanical elements or complex mechanisms in the design of the membrane grid, therefore, they are reliable and durable. The membrane itself is made of weightless synthetic material

To prevent membrane deformation as a result of increasing pressure of air jets in the system, these models are reinforced with stiffeners. The membrane partition rests on them if excess draft occurs.

Type #3 - petal grille models

The petal design is similar to the gravity model.Here the valve is shaped like a louvers. Its work is based on gravity.

In a basement or garage, it is better to install a galvanized petal grille. The valve regulates the air supply by turning it clockwise

The device functions more efficiently if it has several doors. The valve on such a grill can be installed only on the hole or over its entire area.

Type #4 - model with a butterfly-shaped locking device

The butterfly valve has two curtains. It closes under the influence of built-in springs. This model can be installed in any position.

Spring devices operate exclusively in ventilation systems with forced ventilation. They cannot work in networks with natural draft

Having chosen such a grille, you need to check how the springs work under the influence of air pressure. In the latest models, the spring force can be adjusted.

Step-by-step installation instructions

Whatever the configuration of the system, the ventilation grille with a check valve must be placed so that the reverse draft is blocked, regardless of the number of operating fans and hoods.

Before installing the grille, you must perform the following steps:

1. Test the valve for possible jamming. Incorrect orientation will prevent air flow from opening the damper.
2. Compare the dimensions of the product with the shape of the ventilation duct.
3. Additionally reinforce the area adjacent to the hole on the wall.
4. Mark the mounting locations by placing the grille against the ventilation hole.
5. Drill holes for dowels and install them.

Next, install the grille using self-tapping screws.If the installation is carried out on wood or drywall, use a drill with appropriate drill bits.

Concrete and brick can be drilled with a hammer drill with a Pobedit drill bit. Special drills are used for ceramic tiles. The disadvantage of this method is the visibility of the screw heads.

Indoors, grilles are also installed on clip-latches, which are produced for products made of aluminum. They are installed on the frame and inserted into the ventilation opening

This method is not recommended for outdoor installation, because... Under the influence of atmospheric conditions, the fasteners may become loose.

Sometimes the grilles are mounted with self-tapping screws from the inside into the end of the ventilation opening. You need to be very careful here and not over-tighten the bolts. Otherwise, the grille in the corners may be damaged.

This method of fastening is reliable; no self-tapping screws are visible.

If it is impossible to install the grate using the usual method, there is another way. Installation is also carried out using self-tapping screws using fastening plates of various lengths

It is simpler, but less reliable, to attach the grille using glue such as liquid nails, Budamex, Penosil, dragon, titanium.

The adhesive layer is applied evenly to the back of the grille or around the hole along a pre-applied contour. The product is fixed with mounting tape, which is removed after the glue has dried.

After completing the installation of the ventilation grille, the joints must be sealed.

Some operating tips

When choosing a grille, you should take into account three main criteria: the dimensions of the entrance to the ventilation duct, its geometry, and operating conditions.Perhaps you need a decorative grille that does not have a check valve in its design? In this case, we recommend that you familiarize yourself with the existing types of ventilation grilles and features of their operation.

When exposed to low temperatures, louvered grilles may become coated with ice.

As a result of icing, the valves will not completely close the duct inlet. Then the return flow of air into the room will inevitably begin.

In addition, due to the formation of ice, the clearance will decrease and the performance of the hood will drop. To solve this problem, the ice must be removed regularly.

Conclusions and useful video on the topic

How to improve home ventilation using a ventilation grille:

How to install the ventilation grill correctly:

The grille, which has a check valve in its design, is an important element of the ventilation network. It helps create and maintain a favorable climate and prevents negative conditions. By spending a small amount on its purchase, you will significantly increase the level of comfort in your home.

Have you installed a ventilation grill yourself and now want to share your experience with other visitors to our site? Leave your comments about the installation process, write recommendations under this article.

Or maybe you still have questions about choosing the appropriate grille option or installing it? Feel free to ask your questions in the block below - our experts and competent users will try to help you understand all the nuances.