A ventilation grill with a non-return valve is needed to block air flows entering the room. This part helps to solve the problem with bad odors, which appears due to the ingress of air masses from other rooms or the formation of backdraft. Before installing the grille, it is advisable to study the features of its design and purpose, advantages and disadvantages, get acquainted with the existing types, installation and operation rules.
Ventilator grille with non-return valve
The non-return valve grille is an element that includes a protective casing, a fastener, a damper and an outer cover. The damper from the valve can be opened by forced circulation of air masses that move under pressure. The grille is connected to the duct using a flange, it is available in various sizes and can be combined with any type of appliance.
Most of the grilles are made of plastic, this is the most suitable material, since the part is used in rooms with a high level of humidity. It most often has the shape of a rectangle, due to such a design, the lattice is able to close not only the ventilation shaft, but also affect part of the wall. The movable element of the part can be in the form of a circle, rectangle, petal or butterfly, it opens only in one direction.
Advantages and disadvantages
A grille with a non-return valve, regardless of its type, is one of the most popular elements due to a large list of advantages. In the list of pluses, consumers include:
- preventing the traction element from overturning and air ingress from the street or from adjacent rooms;
- good noise absorption, reliable protection of space from unnecessary sounds;
- beautiful appearance that allows you to place elements in interiors of any type;
- no problems during installation and during operation, practicality and reliability;
- wide assortment and selection, variety of dimensions, shades and design options;
- acceptable cost of items.
Among the shortcomings, consumers note the risk of freezing of the gratings in winter and the insufficient performance of some models. You can solve the problem with freezing after installing a heater built into the fan.
Operating principle
The ventilation grill with a valve works according to the standard principle: the exhaust air mass passes through the outer cover using a valve and lifts the damper. After the flow pressure drops, the damper begins to close and becomes a reliable barrier against unnecessary odors, insects, dust and dirt. This detail is indispensable in kitchens and bathrooms, as well as in the rooms adjacent to them.
The check valve prevents the flow of air masses and noise, this is the main difference between such a grill and a conventional analogue without additional protection. The part can be installed both from the outside and from the inside of the building, connecting it to the end side of the air duct and sealing the butt elements.
Existing species
Ventilation grilles with a valve are divided into several varieties, taking into account the type and shape of the locking device. Parts made of plastic are placed indoors, since they do not withstand temperature extremes. Metal counterparts are ideal for outdoor installation, in order to prevent freezing, special heating is used.
Gravity single leaf
These models are standard designs with a circular or rectangular closure. Their principle of operation is to move the damper part using the air flow in the correct direction, which then continues to move freely through the duct. Then the valve is pulled to the base of the ventilation grill and closes it. Gravitational elements are presented in two types: with an offset axis, where the damper is fixed, and with an internal or external counterweight. The device must be installed vertically or horizontally, otherwise the lid will not close completely and will not protect the room.
Petal
Petal variants have a structure similar to their gravitational counterparts. They are equipped with louvred valves, the operation of which is based on the principle of gravity. In the presence of several flaps, such devices function much better. Valves on them can be installed only over the entire area or on one hole.
A ventilation grill with a petal valve is considered the most versatile and practical.
Membrane
Membrane elements are the most popular, lightweight and flexible plates are used as flaps. Due to slight resistance, they close under the influence of gravity. Due to their simple layout and ease of operation, these grilles can be installed in ventilation systems with standard air circulation. To prevent deformation of the membrane under an increase in the pressure of the air jets, the grilles are supplemented with rigid ribs. They serve as a support for the baffle when excessive thrust is generated.
Butterfly
Butterfly valves have two shutters and close under the influence of the springs installed in them. These grids can be placed in various positions; when choosing, they pre-check the operation of the springs under the influence of air pressure. In more innovative versions, the spring force can be changed. It should be borne in mind that butterfly devices work only in forced-type ventilation systems and are not suitable for natural draft circuits.
Selection rules
The choice of a lattice element depends on the design features of a particular ventilation system; in some cases, the parameters are indicated in advance. You can also select a part using special monograms designed for specific requirements. For large systems, air flow and speed become the main selection criteria, so they require custom-made grilles with a special regulator. In addition to technical requirements, attention must be paid to the aesthetics and design of the elements.
In most cases, the choice of a particular model depends on the shade of the part, the need for adjustable blinds and fine mesh. Additionally, they check the noise and aerodynamic properties, characteristics and areas for installation, the installation location, for example, on the floor, ceiling, wall or door. An important parameter is considered the absence of problems during maintenance, the size of the duct or hole, as well as the ability to consume air during operation. At the beginning, you must always take into account the dimensions of the ventilation duct and its geometry, as well as the operating conditions.
The choice of gratings for industrial premises should be entrusted to professionals. If we are talking about details for apartments or houses, you can choose them yourself if you have a project or a ventilation system diagram.
Installation and operation
A ventilation grill with a non-return valve for flowing natural ventilation is installed on the outer part of the wall, some parts are allowed to be fixed in the ventilation shafts. At the first stage, the device is connected to the duct using a connecting flange, filling the gap between it and the wall with a sealant. After the foam hardens, its excess is removed with a clerical or construction knife.
At the next stage, the lattice must be fixed on the supporting surface using dowels or self-tapping screws. You need to choose a fastener taking into account the weight of the part and the material from which the walls of the building and the body of the lattice are made. After completing the installation work, the device can be started in test mode. If the installation is carried out correctly and without errors, in compliance with all safety requirements and rules, the grille will work as stably as possible.
A properly installed grill with a non-return valve is an important part of the hood and ventilation system. With its help, you can reliably protect the air duct from external currents and create an ideal microclimate in the room.
