What is an anti-return valve for hoods: types, purpose

Cooker hood — the same familiar attribute of modern kitchens as microwave, hob, fridge and freezer, etc.

For each type of household appliance, an appropriate place is selected taking into account the requirements of the device.

The hood, which frees us from unpleasant odors in the kitchen, requires not only proper placement above the stove.

It is important to correctly mount its duct to ensure reliable operation.

And here, for the first time, many consumers are faced with such a concept as an anti-return valve.

We will tell you about this element, so that it becomes clear to you what it is and why the part is installed in the device.

Extractor anti-return valve

The concept

Anti-return (or non-return) valve — this is an additional part, usually in the form of a grill, which is specially installed inside the duct pipe.

It is made of plastic or metal. In use, requires regular cleaning.

Purpose of the part

The main purpose of the hood — removal of unpleasant kitchen odors. The device does not just pick them up, but literally collects them, draws them into itself. And then through the duct leads outside the room.

The duct is sometimes mounted in the window. But most often it is built into the ventilation duct. He must be in every kitchen. A decorative grill is used to separate the channel from the interior. It is in her place that the duct pipe is inserted.

However, there may be times when the air stream changes direction. And instead of moving from the premises to the ventilation, on the contrary, it enters the apartment from the ventilation duct.

The cause of the change in direction is the resulting reverse thrust. It may appear, for example, due to strong winds.

Important: the main task of the anti-return element — neutralization of back draft, protection of internal premises from cold air and unpleasant odors from the street or from the ventilation shaft.

Types of Anti-Return Valves

In exhaust devices, reverse elements of different types are installed.

• Membrane— special protective film that allows air to pass in only one direction: from the kitchen.

• Blinds (petals)— several records, the device of which is similar to window blinds. The plates in the absence of reverse thrust can have a horizontal arrangement, allowing air to pass between them. And with it, take a vertical view and block the access of street air.

• Bivalve (butterfly)— two wings that close and open.

They use different ways of driving. The grill may close under the mechanical influence of an air mass of a different direction. Electric control is also possible.

Is an anti-return valve required

By purchasing a range hood, many buyers cannot decide for themselves whether they need this part. Perhaps the installer is imposing a service they do not need?

To decide, we turn to the advice of professionals. They give the following clarification. The need for anti-return valve

is determined in each case individually and depends on the characteristics of the mounting of the duct.

• If his the pipe has a simple direction in a straight line, check valve necessary!
• If this the pipe has twiststhen you can refrain from installing the valve. The reverse thrust in this case will be extinguished by these angles and turns. The grill in this case can be installed additionally, but you can not do this.

We conclude: check valve — an additional way to provide clean air in the kitchen. Now you can make the right decision whether your device will need such an addition.