How to increase chimney draft

Combustion products formed during the operation of the heating boiler, with the air flow are carried along the chimney to the street. The process of movement of the flow through the exhaust channel is called a burden. It arises due to the difference in pressure and density of cold air and heated in a furnace or boiler. Improper design of the chimney or its clogging lead to a decrease in the intensity of the air flow, and sometimes change its direction to the opposite. Weak traction reduces the efficiency of the heating system, and the reverse represents a health hazard. To improve the combustion of fuel in the boiler, you need to know how to increase the draft in the chimney.

Thrust check using available tools

The productive work of heating depends not only on the presence of thrust, the quality of the fuel also affects the combustion temperature. To exclude other factors, you need to check whether the air moves through the chimney. How to check the draft without a special device? To do this, you need the items at hand and simple actions:

1. A burning match is brought to the firebox, during normal firing, the flame retracts inside the furnace.
2. A lit candle is placed near the chimney and extinguished, the direction of air movement is determined by the smoke.
3. A piece of tissue paper is inserted into the hole in the channel and monitored for vibrations.
4. The traction is not only insufficient, but also excessive, while the heat is quickly carried to the atmosphere. The strong air flow causes the flame in the firebox to hum.

Lack of traction

It is important to determine why there is no traction. Reduced thrust provoke various reasons:

• improper chimney construction;
• low location of the edge of the pipe relative to the ridge of the roof;
• a large amount of soot deposits on the walls of the chimney or other forms of clogging;
• climatic conditions - low pressure, high humidity, strong wind;
• insufficient air flow due to poor ventilation of the room;
• violation of the tightness of the channel.

Having found out the reason for the reduction of thrust, immediately begin to correct the situation. Most of the listed defects can be eliminated by yourself.

What to do

And now let's figure out how to improve cravings. Structural errors, such as narrow pipe diameter or multiple channel bends, will have to be resolved by shifting, but other cases have simpler solutions. Insufficient height of the pipe is corrected by increasing, if brick was used, then additional laying is carried out. An additional detail is fixed on the metal pipe, bringing the structure to the recommended height - 5 m from the firebox.

The narrowing of the channel, caused by the accumulation of soot, reduces the volume of gas flowed. To clean the chimney, a simple device is made of a brush and a load tied to a rope. The device is lowered into the pipe and the translational movement cleans the passage.

Violation of the tightness of a brick chimney is eliminated by smearing the gaps with a solution, if necessary, shifting part of the pipe. With sufficient size and straight construction of the channel, they are gilded with a ceramic or metal pipe. The chimney becomes airtight, and the circular cross-section of the channel is more effective for the discharge of gases than the rectangular one.

Note! The diluted air in the room does not provide enough oxygen and has a low pressure, this provokes reverse traction. To increase the pressure, good ventilation is needed, it is enough to open the windows for a few minutes and the composition of the air will be restored.

In adverse weather there are several ways to improve traction.

1. If the outside temperature is low, cold air creates pressure that prevents outflow. To heat the pipe, you can burn some paper with it, it is also important to take care of the insulation of the structure.
2. Use strong wind to increase thrust allows the installation of the deflector. This device is placed on the pipe, at the time of exposure to air masses in it there is a low pressure, which increases the thrust. The diameter of the vent depends on the size of the chimney. In the absence of wind, the device has no reinforcing effect. The devices are made of stainless steel, they are resistant to high temperature and humidity.
3. A similar effect has a rotary turbine installed on the tip. It rotates under the action of the wind and creates air movement in the smoke channel. The design in the form of a ball with blades protects the smoke channel from precipitation and foreign objects. The turbine is installed for a gas boiler with a low temperature of exhaust gases.
4. To protect the mouth of the pipe from wind blowing allows the installation of a weather vane. The device rotates so that the smoke comes out from the leeward side, and the air flowing around it increases the thrust. Weathervane reduces the likelihood of tipping thrust in the chimney. So that the mobile part does not suffer from corrosion, it must be lubricated; periodically the vane is also cleaned of soot.

Note! One of the reasons for the lack of traction can be a closed chimney gate (flap), if this is the reason, then after opening the air flow is normalized.

Thrust stabilizer device

The thrust stabilizer is a pipe having an umbrella-shaped expansion. In this place is a hole for the flow of air. The work of the stabilizing device is controlled by the sensor. When gases accumulate from reverse thrust or poor passage through the channel, it heats up and turns off the boiler. After eliminating the causes of deterioration of the traction, the heater is turned on again. The stabilizer, by supplying additional air, optimizes the velocity of the gas through the chimney. It automatically changes the intensity of movement of products of combustion, depending on the situation, increases or decreases cravings.

Installation of forced traction

Even minimal traction is normalized with the help of a heat-resistant fan installed on the flue duct. The device is powered by an electric motor and requires the laying of a wire for mains supply. This is the most effective solution to enable the movement of air mass in the chimney, despite the weather conditions or other factors. Due to the rotation of the exhaust fan blades, a forced draft is created. The electrical device will improve the discharge of gases, even in the channels, where a small diameter of the pipe is selected by mistake. The insufficient height of the chimney is also compensated by the installation of the fan. Unlike mechanical devices, working only from wind energy, the electric fan is ready for operation under any conditions.

Good traction - an important component of the effective functioning of the heating system, work on its control and strengthening will ensure stable operation of the boiler or furnace.