For the productive operation of the ventilation network, it is necessary to adjust the volume and speed of the air masses passing through it. For this purpose, a special device is mounted on the chimney - a slide damper for ventilation.
Description of the concept
The ventilation gate serves to restrict or completely block the passage of air flow. The device has the shape of a valve. Parts similar in design are used in cooker hoods and water drainage systems. Gates are used for air ducts from any material, including polypropylene and plastic in general. Since fire safety rules require that the chimney be made of refractory material (brick or steel), a metal damper must be used for it.
The mechanism of operation of the part is identical to that of the usual valve used to control traction in the pipe. When the fuel is ignited, an open throttle activates the movement of air flows. While the wood or peat burns out, the part is left only slightly open to prevent smoldering too quickly. When the process is complete, you can close the passage. The ventilation gate operates according to a similar scheme: it activates, then blocks the flow of air. An element can control the flows from the main node to the outgoing branches.
Gate classification
The classification of valves for ventilation can be carried out on several grounds. They differ in shape, design, installation method on the chimney, methods of control of work.
In shape
The cross section of the airway may be in the form of a circle or a rectangle. Accordingly, the part to be installed is selected. According to statistics, a gate for a round duct is used very rarely. It can only be mounted on a tube of an appropriate shape. Rectangular gates for ventilation are more common.
There are situations when it is impossible to install a round ventilation gate, only mounting rectangular parts is permissible. This includes systems with electric heaters, as well as cases where the valve needs to be hidden, but there is not enough free space.
By design
The most popular and reliable designs are retractable. They are widely used in tin and brick chimneys. This type of device provides:
- passage of air masses with a minimum of losses;
- greatest tightness;
- simplicity of the chimney cleaning procedure.
There are rotary models. They do not have high reliability - the movable component of the mechanism easily fails. Use them when the design or technical features do not allow you to mount a retractable product. In the middle of the device is a twig. A sheet of metal is attached to it, rotating around its axis.
By type of management
In addition to traditional handicrafts, there are automatic gates, as well as devices with hydraulic and pneumatic control. The electrically operated gate for ventilation is opened and closed by pressing a key (usually a remote control).
According to the material of manufacture
Gates for chimneys are made of steel sheets of various types. The material may be chrome plated, alloyed or coated with anticorrosion.Parts intended for installations that do not require high temperatures can be made from other materials, such as plastics.
Features of installation and installation methods
The most common type of installation is to place the device in front of the fan outlet. When their location is identical, the mounted gate is called launcher. Such a part protects the power plant from excessive heating.
The ventilation device is only started when the damper is in the closed position. If done differently, the fan will receive excessive load. If this rule is regularly neglected, the equipment will become unusable.
Some products are designed to be installed directly in the chimney. Others are supposed to be mounted using fixing fasteners. This includes the flange method.
Wafer joint
The easiest method to perform is to install the valve directly into the chimney pipe. This type of placement of the part is attractive in that it involves the use of additional parts for mounting the mechanism. However, not all types of gates are designed for installation in this way.
Another method is the installation of a valve in front of the chimney outlet or in the furnace itself. In this case, the part becomes a component of the heating structure. However, there is a height restriction. The installed valve must be at a height of no more than 1 m.
Flange connection
When fixing the valve using a flange, certain installation standards must be taken into account. The chimney-fixing parts must be located at a certain distance from the damper itself. Mounting them together with the gate is prohibited. Also, fasteners must be placed strictly on a certain side of the flange. This connection requires additional sealing.
How to make a gate for do-it-yourself ventilation
To make a slide equipped with a sliding plate for ventilation with your own hands is quite simple. First you need to find out the dimensions of the cross section of the chimney using construction tape. Based on them, prepare a simple drawing.
The most affordable materials for home flaps are galvanized sheet and stainless steel. It is necessary to prepare 2 sheets of one of these metals. A thickness of 0.7 mm is suitable. A frame is placed between the sheets, the parameters of which depend on the dimensions of the chimney. Bends are made around the perimeter of the shutter. A hole is cut in the center to combine the two nozzles. For fastening, a heat-resistant hermetic composition is used. A plate is inserted between the layers to block the traction.
Using a chimney flap allows you to control the draft level. You can buy ready-made gates in a shell made of carbon steel sheets or make a part at home.
