Most private houses and cottages are equipped with gas, solid and liquid fuel autonomous heating systems. The efficiency of heating the coolant largely depends on the quality of the output of the combustion products and the volume of fresh air entering the furnace. When the boiler is turned off, it becomes necessary to close the outlet channel so that warm air from the room does not suck in and foreign objects do not enter the furnace. To perform these tasks, a chimney damper is used - a simple but effective device invented many centuries ago almost simultaneously with the advent of the first furnaces. The part can be supplied with the boiler or purchased separately. If you have ordinary household tools and the ability to handle them, you can make a damper for the chimney stove with your own hands. To do this, you should familiarize yourself with the purpose, principle of operation and manufacturing technology of this device.
Definition of the concept of chimney flaps
The chimney damper is a device with which the channel coming from the furnace is completely or partially blocked for the removal of combustion products. The product can be used in heating and ventilation systems. The valve in the chimney works similarly to a water ball valve cut into a water pipe.
By performing various manipulations with the help of a gate, the size of the pipe section is regulated. This allows you to increase traction to quickly warm the room or reduce it in order to save fuel and maintain the combustion process at the desired level. The valves in the chimney are made of hard metal that can withstand temperature extremes, mechanical stress and corrosion.
Device and principle of operation
Since the chimney gate is exposed to high temperatures, moisture and chemically active substances, the part is made of cast iron or stainless steel - materials with high performance characteristics.
Structurally, the valve on the chimney pipe is a shut-off equipment, consisting of a body and an adjustable element having a different configuration and tuning technology. The intensity of the movement of furnace gases is adjusted by displacing the valve horizontally or around its axis. The valve is made according to the configuration of the pipe and can be installed in channels of rectangular, square and round cross-section.
The principle of operation is to adjust the thrust by expanding or narrowing the outlet channel. During kindling and to achieve maximum temperature in the furnace, the valve completely releases the pipe. When the desired temperature is reached and the stove is switched over to continuous combustion, the damper shuts off the chimney until the optimum ratio of the incoming air and the exhaust gases is reached. In the periods between the use of the boiler, the device is in a closed state.
The range of application of gates is almost unlimited. They are mounted in potbelly stoves, heating boilers, stoves in a bathhouse. The installation of dampers prevents the combustion products from blowing into the room when back draft is formed.
Types of chimney flaps
Different types of damper can be used to control the flow of combustion products.The choice is made based on the configuration of the channel and the material of its manufacture.
The following design solutions are possible:
- Retractable installation. The product is a round or rectangular plate moving along the guides inside the pipe. Due to the presence of openings inside the channels, the frame is held in the nest, holding tightly in the pipe. Adjustment is carried out by feeding the plate forward and backward to achieve a given result. More often, retractable devices are used in square brick pipes. In channels of circular cross section, they also perform their functions effectively.
- Throttle A classic swivel gate for a chimney consists of a steel or cast-iron plate rotating around its axis. The rod is inserted into the holes in the walls of the pipe and is not removable. The gas flow is adjusted by turning the frame to a certain angle, after which the product is fixed. Various models are equipped with manual or electric drives, including those with remote control.
The air damper can be an independent or auxiliary element of the chimney. Its task is to close the chimney from blowing out strong gusts of wind and after the end of the furnace. Traction adjustment is due to the force of the spring, which connects the pipe to the damper. It is not difficult to make such a gate for a chimney with your own hands, but it will bring many benefits.
Advantages and disadvantages
Like any engineering design, furnace dampers have their pros and cons.
Among the advantages include:
- the ability to adjust traction;
- saving fuel by reducing the volume of air supply to the furnace;
- heat preservation of the furnace after closing the chimney;
- blocking wind blowing.
Design disadvantages:
- throttle type products are unreliable, can wedge and not be closed from soot adherence;
- rotary devices make it difficult and sometimes impossible to clean the channels;
- Proper adjustment requires experience and skills.
With proper installation and proper handling, the gates allow you to make the boiler furnace more convenient, economical and safe.
Methods for installing a chimney damper
There are the following rules and methods for installing the gate in the chimney:
- in masonry - at a height of 60-80 cm from its base;
- in a steel pipe - butt-to-butt (into sockets) in a section that is not insulated;
- the height from the outlet of the metal chimney is at least 150 cm to prevent thermal deformation;
- the shutter should move in the grooves and rotate on the shaft freely, without jamming;
- production of a hole in the valve for the release of carbon monoxide during early blocking of the channel.
In all cases, marks should be made on the damper handle with the help of which its position in the pipe is tracked.
Do-it-yourself damper manufacturing
The initial step in the manufacture of a valve on a chimney pipe with your own hands is to take measurements and draw up a drawing. Based on the project, materials and equipment are calculated.
To work, you will need:
- drill, grinder, welding machine;
- hammer;
- vise;
- pliers;
- core;
- tape measure, compass, marker;
- stainless steel sheet 2.5-3 mm;
- rod for the frame.
Particular attention should be paid to product dimensions. The holes for the shaft must exactly match horizontally. An allowance of 1-2 mm should be taken, as the steel expands when heated. The frame should not touch the inner edges of the guides, and the throttle should not touch the walls of the pipe. Before final fixing, the product should be checked in all operating modes.
