Ventilation grille with non-return valve: device and types + installation recommendations

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

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

We will also analyze the process of self-assembly and the rules for operating this device.

Design and advantages of the grille with valve

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

The stationary part is the lattice itself. It acts both as a decorative element and as a barrier protecting and closing the valve from accidental damage.

Since the grille closes the ventilation hole, no smell penetrates from the street, all kinds of small particles. When lowering the temperature from the outside, the grill prevents heat loss

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

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

They produce a valve for plastic grilles, since they have to be operated under aggressive moisture conditions.

A cutaway flange looks like a circle. Its diameter is from 11 to 15 cm. By means of a flange, the valve is integrated into the duct

Such a ventilation grill has several advantages:

1. It will protect against street air, both cold and too warm.
2. Insects or dust will not enter the room.
3. The room will be protected from odors.
4. The presence of a sound-absorbing effect will not allow the penetration of extraneous sounds.
5. Simple installation and maintenance.
6. Aesthetic look of a decorative lattice.

The main disadvantage is that with minus, the blinds or petals can freeze. To solve this problem, a heater is built into the system.

When is a check valve grill 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 extreme need for it, but for prophylaxis, it is still worthwhile to install a grate.

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

The following factors can cause reverse thrust:

1. The absence of air into the room or a reduction in its volume.
2. Debris entering the hole.
3. Failure of the elements that control the movement of air flow.
4. The operation of hoods of high power.
5. Not taken into account when designing a house, the wind blowing constantly.
6. The presence of several pieces of equipment in the ventilation system, working simultaneously with the outflow of air.

All these circumstances create the 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 these factors will not appear. It is better to secure your ventilation system by installing a grill 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:

• gravitational single-wing;
• petal;
• membrane;
• butterfly.

Ventilation grills are made of plastic and galvanized metal.

Now check valve vents are very popular. With their help control the air flow. Often these products are used in bathrooms and toilets.

The former do not tolerate subzero temperatures, therefore, they are mainly used for indoor installation. They have low weight, high corrosion resistance, long life, low price.

Outside, metal gratings are usually installed. So that in winter they do not freeze, they use heating. The shape of the lattice can be rectangular, round.

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

View # 1 - single-leaf gravitational grate

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

The work is based on the fact that the air flow, having the right direction, pushes the flap and then moves freely through the duct. A reverse avalanche pulls the valve to the core of the grate and closes it.

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

There are two options for the execution of such models - with a displaced axis of fastening of the damper relative to the axis of the duct pipe and with a counterweight located outside or inside the device.

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

View # 2 - membrane version of the device

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

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

In the design of the membrane lattice there are no mechanical elements and complex mechanisms, therefore, they are reliable and durable. The membrane itself is made of weightless synthetic material.

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

View # 3 - petal lattice models

The petal design is similar to the gravity model. Here the valve is in the form of blinds. His work is based on gravity.

In the basement or garage, it is better to install a petal galvanized grate. The valve controls the air supply by turning in the clockwise direction

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

View # 4 - model with butterfly locking device

Butterfly valve has two curtains. Its closure occurs under the influence of mounted springs. You can install such a model in any position.

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

Having chosen such a grate, it is necessary 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

No matter what configuration the system has, the ventilation grille with a non-return valve must be positioned so that the reverse draft is blocked regardless of the number of fans and hoods working.

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

1. Test the valve for possible jamming. Incorrect orientation will prevent airflow from opening the damper.
2. Compare the dimensions of the product with the shape of the ventilation duct.
3. To additionally fix on the wall the area adjacent to the hole.
4. Mark the locations for fasteners by attaching the grille to the ventilation hole.
5. Drill holes for dowels and install them.

Next, mount the grille using self-tapping screws. If the installation is done on wood or drywall, use a drill with appropriate drills.

Concrete, brick will be able to drill a hammer drill with a drill. For ceramic tiles use special drills. The disadvantage of this method is the visibility of the heads of the screws.

Indoors, the grilles are also mounted on snap clips, which are released for products made of aluminum. They are mounted on the frame and inserted into the ventilation opening

For outdoor installation, this method is not recommended, because under the influence of atmospheric phenomena fasteners may weaken.

Sometimes the grilles are mounted on self-tapping screws from the inside to the end of the ventilation opening. You must act here very carefully and do not overtighten the bolts. Otherwise, the grill in the corners could be damaged.

This method of attachment is reliable, self-tapping screws are not visible.

If it is impossible to install the grille in the usual way, there is another way. Installation is also carried out on self-tapping screws by means of mounting plates of various lengths

It is easier, but less reliable, to fasten the grate to glue such as liquid nails, budamex, foam silo, dragon, titanium.

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

After the installation of the ventilation grill, the joints must be sealed.

Some operating tips

When choosing a grill, three main criteria should be taken into account: the size 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 existing types of ventilation grills and features of their operation.

Under the influence of low temperatures, grilles equipped with shutters can become covered with ice.

As a result of icing, the valves will not completely close the duct inlet. Then the return 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, ice must be regularly removed.

Conclusions and useful video on the topic

How to improve ventilation at home with a ventilation grill:

How to install the ventilation grill:

The grille with a check valve in the design is an important element of the ventilation network. It contributes to the creation and maintenance of a favorable climate, prevents negative conditions. Having spent a small amount on its purchase, you will significantly increase the level of comfort in the house.

You yourself installed a ventilation grill 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 a suitable version of the grill or how to install it? Feel free to ask your questions in the block below - our experts and competent users will try to help you deal with all the nuances.