Fire protection of air ducts: purpose, varieties, methods

In the process of designing ventilation systems, it is important that the fire protection of the air ducts be made correctly. The engineer must first of all take care of the safety of the people in the building. At the same time, properly performed protection of air ducts from high temperatures plays a significant role in this process.

Requirements and norms

To remove from the premises of used air, a ventilation system of the channels passing through all floors and crossing various fire compartments is used. In the event that the fire protection of the ducts has been ignored, in the event of a fire, smoke and a flame may spread in a matter of seconds from the place of ignition to the building as a whole.

In accordance with fire regulations and regulations, each ventilation system must fully meet the fire protection requirements of the air ducts. It is possible to conduct air ducts through fire walls, partitions and ceilings only if all precautions are strictly observed. In addition, any possibility of transferring fire and smoke through floors and staircases should be excluded.

What is the fire resistance of air ducts for?

With the use of modern materials that protect the air duct system, you can simultaneously solve several problems:

• Increase the strength, service life and stability of the ventilation system to external negative factors.
• Protect against ventilation the ventilation ducts.
• Prevent the emergence of situations that pose a danger to life and health of people if they can not be evacuated in a timely manner from the building in which the fire has arisen.
• Also, the fire protection of the smoke exhaust ducts makes it possible to increase the thermal insulation performance of ventilation systems.

Areas of use

The need to provide adequate fire protection for ventilation systems has led to the development of a wide range of methods and means that will reliably protect air ducts from exposure to high temperatures. To date, they have found their application in the arrangement of various types of channels, smoke removal and air conditioning systems, as well as technological ventilation, gas systems and much more.

Varieties

Depending on the characteristics of the action, chemical composition and application, the fire protection system of the ducts can be represented in the following variations:

• Roll coatings of mineral or chemical composition, which are characterized by a high level of fire resistance.
• Fire protection mixtures. This is a kind of plaster, which covers the elements of the ventilation system to protect them in case of fire.
• Mounted fire retardant smoke ducts, which is fixed by means of fasteners or special adhesives.

• Fire retardant coatings, which contain fire retardants. These are substances characterized by their ability to transform into an insulating coating, preventing the supply of oxygen, which is the catalyst of the combustion process. These substances have special chemical properties: they do not degrade the properties of the treated surface, do not react with metal and water, cause corrosion of the first, do not interfere with the performance of finishing and repair.

In our country the most popular means of fire protection of ventilation systems are finished materials. They are produced in the form of perlithophosphogel, asbestos-cement slabs and gypsum-fiber or gypsum boards. Their use makes it possible to increase the overall fire protection index, and also creates an additional heat-absorbing and heat-shielding layer.

If the required fire safety index is in the range of 15-150 minutes, then with the use of flame retardants it can be up to 240 minutes. These materials do not pose a health hazard, although their price is quite comparable, and sometimes even lower than that of protective varnishes and paints.

Methods of fire protection

In most cases, the fire protection of air ducts is carried out mechanized, traditional and combined by means of special materials, compositions and coatings.

1. The mechanized method is the most effective and high-tech. However, its use requires the availability of specialized equipment.
2. Traditional fire protection ducts (its price, compared with the previous method, much lower) is performed through reinforcement, which increases the load on the fixing of air ducts. This option does not require the use of special equipment. However, this procedure is very laborious.

Combined treatment of air ducts combines the advantages of the two previous methods. It is produced manually with the use of combined compounds, which are applied to the metal surface, after which this composition is laid on the foil basalt cloth. This method, due to its quality and economy, is very popular.