The fire, as well as the followingthe spread of smoke in the room leads not only to large financial losses, but also to death. Most of us believe that in a fire, the main danger comes from exposure to high temperatures, but sad statistics prove that exposure to harmful substances and products of combustion is no less dangerous to health.
Operating principle
The natural smoke removal system is based onair heat flow principle. It has several ways to control the mechanisms: remote control of smoke exhaust hatches using infrared rays, control panels and special sensors, as well as manual buttons.
Natural induction ventilation systemscan be used in all types of premises, you just need to choose the necessary scheme. SNiP (sanitary norms and rules) determine all the necessary indicators of fire resistance for each type of premises.
Depending on the purpose of the enterprise and itspatency can be installed various combinations of the system: separate windows with electronic control for enterprises with small crowds of people or special complex systems that meet the more serious fire safety requirements.
Design and calculation of smoke hatches
The design of smoke removal systems is carried out in several stages.
First of all, it is necessary to study all the technical documentation on the installation site.
The next stage involves the inspection of existing ventilation shafts (if available) and their detailed analysis. And only after that you can proceed directly to the calculations.
Inspection of the design object is very importantstage, because only after it you can choose the most suitable equipment for the premises. If there are no ventilation shafts at the facility, the specialists determine whether there is a possibility of additional communications. If there is such an opportunity, you can start the calculation.
Smoke hatches
Hatches are designed to ensure that with their help:
- Natural uniform lighting.As is known, overhead lighting is twice as effective as side lighting. Since smoke hatches light up almost every square meter of space, the cost savings of lighting are quite substantial. In addition, natural daylight improves performance and improves well-being, which is very important in office space.
- Natural ventilation.The constant circulation of fresh air ensures the maintenance of a comfortable temperature in the room, which again allows us to significantly save the cost of artificial ventilation.
- Smoke removal. The removal of smoke in an emergency situation ensures the efficient use of escape routes and the effective work of rescue services.
- Significant simplification of engineering systems. Smoke removal hatches in certain cases can eliminate the need to use artificial air vents.
Smoke hatches control systems
Smoke removal hatches are controlled with the help of specialized systems of three types: ventilation control system, smoke removal control system and mixed system.
Systems are also divided according to the type of control mechanism. They can be of three types: pneumatic, electric and pneumatic-electric.
Smoke removal hatches activate control systemautomatically using special sensors that respond to rising air temperature or smoke in the room. However, at the request of the client, the smoke removal system can be additionally equipped with remote and manual start-up devices, as well as launch through a fire alarm system.
In addition, the ventilation control systemhatches can be equipped with special sensors and weather station. In this case, with strong wind and precipitation, smoke exhaust doors will automatically close.
Practical recommendations for installation of smoke hatches
The main condition under which the installation of hatchessmoke removal can be considered correct, is their uniform location on the roof of the building. However, if materials of different burning intensity are located indoors, uneven placement of hatches is allowed.
When installing the hatches should take into account the angleroof: if it is less than 12 degrees, then the maximum distance from the edge of the roof to the hatches is 10 meters, if it is more than 12 meters - the distance increases to 20 meters.
The distance between the hatches must be at least 20 meters and not less than the sum of the long sides of the two hatches (or their diagonals).
From a practical point of view, much more efficient.its task will be to cope with a large number of small hatches, rather than a small number of large ones. A roof slope of less than 12 degrees implies a mandatory installation of at least one hatch per 200 square meters. m, more than 12 degrees - 400 square meters. m
Smoke removal hatches can be installed onroofs with different types of coating: membrane, reinforced concrete, etc. It is mandatory to take into account the layout and load, calculated at the design stage. The most frequent consequence of errors at this stage is overcooling of the room in winter and overheating in the hot season.
Special requirements
When determining the number of smoke hatches in crowded places, their area should be equal to or more than 3% of the floor area of this room.
Методика расчета площади люков дымоудаления theater is as follows: if the floor area of the stage is less than 150 square meters. m, the smoke hatches should be at least 3% of it. If the surface area of the scene exceeds 150 square meters. m, the area of the smoke hatches is calculated by the formula: A = 0.5 √ 2F-100 (F is the surface area of the scene floor).
Thus, the article discusses in detail the types of smoke hatches and issues of their installation.
