In the process of designing ventilation systems, it is important that the ventilation ducts are properly protected. An engineer must first of all take care of the safety of people in the building. At the same time, well-executed protection of ducts from the effects of high temperatures plays an important role in this process.
Requirements and Norms
To remove used air from the premises, a ventilation system of channels passing through all floors and crossing various fire compartments is used. If the fire protection of the ducts was ignored, in the event of a fire, smoke and flame can spread in a matter of seconds from the place of ignition to the building as a whole.
In accordance with fire regulations and rules, each ventilation system must fully meet the established requirements for fire protection of air ducts. Air ducts can be led through fire walls , partitions and ceilings only if all safety precautions are strictly observed. In addition, any possibility of transferring fire and smoke to floors and stairwells should be excluded.
What is fire protection for ducts for?
When using modern materials that protect the duct system, several tasks can be solved simultaneously:
- Increase the strength, durability and resistance of the ventilation system to external negative factors.
- Protect ventilation ducts from fire.
- To prevent the occurrence of situations that pose a danger to the life and health of people in case of impossibility of their timely evacuation from the building in which the fire occurred.
- Also, the fire protection of the smoke exhaust ducts allows to increase the thermal insulation performance of ventilation systems.
Areas of use
The need to provide adequate fire protection for ventilation systems led to the development of a wide range of methods and means that will reliably protect air ducts from high temperatures. To date, they have found their application in the arrangement of various types of channels, smoke exhaust and air conditioning systems, as well as technological ventilation, gas systems and much more.
Varieties
Depending on the features of the action, chemical composition and application, the fire protection system of the ducts can be presented in the following variations:
- Mineral or chemical roll coatings characterized by a high level of fire resistance.
- Fire retardant mixtures. This is a kind of plaster, which covers the elements of the ventilation system to protect them in case of fire.
- Mounted fire protection of smoke exhaust ducts, which is fixed by means of fasteners or special adhesives.
- Fire retardant coatings, which contain flame retardants. These are substances characterized by their ability to turn into an insulating coating that prevents the ingress of oxygen, which is a catalyst for the combustion process. These substances have special chemical properties: they do not worsen the properties of the surface being treated, do not react with metal and water, cause corrosion of the former, and do not interfere with 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 perlite-phosphogel, asbestos-cement plates and gypsum-fiber or drywall sheets. Their application allows to increase the overall fire protection index, and also creates an additional heat-absorbing and heat-shielding layer.
If the required fire safety indicator is in the range of 15-150 minutes, then when using fireproof plates it can be up to 240 minutes. These materials do not pose a health hazard, despite the fact that their price is quite comparable, and sometimes even lower than that of protective varnishes and paints.
Fire protection methods
In most cases, fire protection of ducts is carried out in a mechanized, traditional and combined way through special materials, compositions and coatings.
- The mechanized method is the most effective and high-tech. However, its use requires specialized equipment.
- The traditional fire protection of the air ducts (its price is much lower compared to the previous method) is through reinforcement, which increases the load on the duct fasteners. This option does not require the use of special equipment. However, this procedure is very time consuming.
Combined ductwork combines the advantages of the two previous methods. It is made manually using combined formulations that are applied to a metal surface, after which this composition rests on a foiled basalt sheet. This method, due to its quality and economy, is very popular.