Exhaust fan with non-return valve: features, pros and cons, how to choose

Exhaust fan with check valve provides air exchange in rooms, and prevents the penetration of unpleasant odors from the general ventilation. Such devices differ in design, type of control, materials and other characteristics. In this article, let's break down the features of check valves, pros and cons, as well as a few criteria to focus on when choosing.

Features

The functionality of such a ventilation device is primarily influenced by the type of check valve. It has such features:

• The flaps of the valve can be silicone, plastic or metal. In the home, devices made of plastic or silicone are used. They do not deteriorate from moisture, do not make a ringing noise and do not require maintenance. Metal devices are installed in industrial ventilation systems.
• The shape of the check valve must match the cross-section of the ventilation pipe. It can be rectangular and work on the principle of louvers - horizontally arranged blades move under the influence of flows from the fan. At round models flaps of the valve can be half or one-piece.
• Manual operation is more reliable and does not depend on electricity supply. Automatic control allows more accurate and faster adjustment of the exhaust fan.
• The capacity of the check valve depends on its size - the larger it is, the wider the duct, respectively more air passes through it.

The design of exhaust fans comes in two types. Axial models consist of a fan on the axis, which creates a draft of air from the room. The performance is high, but the equipment is noisy. Ducted exhaust fans are made in the form of a snail with a turbine inside. They work quieter, but they cost significantly more than axial models.

Pros and cons

Exhaust fans with a non-return valve have such pluses:

• Unpleasant odors from neighbors: tobacco smoke, soot, fragrances of deodorants or cologne from the bathroom and toilet do not enter the room.
• Exhaust fans with non-return valves can be installed in rooms of any size, in small bathrooms.
• They are compatible with various types of ducts.
• The devices are mounted on the wall or ceiling.
• Protection against moisture prevents short circuits. Therefore, silicone or plastic exhaust fans are installed in wet rooms.
• There are models with a timer, a humidity sensor.

Cons:

• The flaps can flap when there is a strong draft, when they close. This is especially audible in gusts of wind. 
• If the exhaust fan is installed in the kitchen, you need to periodically clean it from grease.
• Quality equipment does not come cheap.

How to choose a check valve

Pay attention to such technical characteristics:

• Power allows you to determine how much electricity the exhaust fan will consume per unit time.
• Performance of the device indicates how much air is drawn out of the room per unit time.
• The operating voltage determines how much power the power grid should have.
• The level of noise that the equipment emits is specified in the documents. This indicator depends on what material the flaps of the valve are made of, how securely the parts are fixed.

For domestic conditions, most often install systems with self-closing flaps. There are also controlled and self-closing types of check valves.