Smoke in the premises is extremely dangerous for the life and health of people who can get severe poisoning from smoke and carbon monoxide with severe or irreversible consequences. To prevent this from happening, in the complex of measures for fire protection of buildings, one of the mandatory components is a smoke protection system, which is a special system of supply and exhaust ventilation devices. Our company "Alfa-Project" will design smoke ventilation systems for you at a highly professional level.

The design of the smoke exhaust system must take into account all the necessary requirements in accordance with the regulatory documentation. The provision of non-toxic parameters of the air environment during the evacuation of people and cleaning the premises from harmful impurities in the air depends on the competent drafting of the project. We always warn our customer that any subsequent reconstruction of the premises requires a change in the remote control system, since it significantly affects the quality of smoke extraction and requires a recalculation of the project.

For more information on the development of a smoke removal (DU) project and the procedure for performing work, please call 211 11 22 , via the online form

WHAT IS A FUME PROJECT?

A smoke protection system (smoke removal, DU) is a complex of organizational measures, space-planning solutions, engineering systems and technical means aimed at preventing or limiting the danger of smoke from buildings, structures and structures in case of fire.

Smoke removal (DU) is a controlled gas exchange of the internal volume of a building in the event of a fire in one of its rooms, preventing a damaging effect on people and material values ​​of the spreading combustion products, which cause an increased content of toxic components, an increase in temperature and a change in the optical density of the air environment. Smoke exhaust systems can be with artificial and natural induction:

1. Exhaust with artificial induction (smoke ventilation) is carried out through special shafts made of non-combustible material, with a standardized fire resistance limit of their fences, which is carried out using valves and forced exhaust, while smoke removal provides for automatic opening of valves in case of fire and switching on fans from fire alarm detectors, installed in the building or remotely from buttons installed on each floor in fire hydrant cabinets.
2. In smoke removal systems with natural induction (exhaust ventilation), it is carried out through special devices: smoke hatches, smoke shafts with smoke valves, which open automatically when the fire-prevention automation is triggered, through non-blown out lanterns that can be opened.

Design stages of the smoke exhaust section

The design process includes the following steps:
• determination of the list of premises, corridors to be equipped with remote control systems, selection of premises for installation of the remote control system, determination of the list of staircases and lift shafts that require external air supply;
• examination of available ventilation shafts for suitability as smoke extraction systems;
• calculation of remote control systems and air pressurization for the installation of ventilation equipment of the required parameters;
• providing the customer with working drawings of the control system, specifications of equipment and materials for approval.

Design of smoke exhaust for industrial buildings
When designing the remote control of industrial buildings, you can choose any of two systems - mechanical or natural. In the first version, special axial, radial (centrifugal) and roof fans are used, the systems have a branched network of air ducts and separate fire zones. As for the natural method of smoke removal, in this case, windows that are located higher than a person's height or fire-prevention skylights with opening ventilation hatches are used.

Design of smoke exhaust for civil buildings
The dimensions of the areas of country houses and cottages are significantly smaller than industrial ones. Therefore, ventilation and smoke removal is carried out using automatic window openers, which react to a dangerous fire situation, rain, wind, heat and can open and close themselves.

The composition of the smoke removal project (DU)

• Explanatory note;
• Calculation of smoke removal systems;
• Calculation of air pressurization systems;
• Selection of ventilation equipment, including valves, air ducts, fans, etc .;
• Axonometric diagrams;
• Hardware Specification;

The list of initial data for the development of control systems:

• Section AR. Architectural and space-planning solutions.
• Subsection HVAC. Heating, ventilation and air conditioning.
• Section PPM, BCH. Fire safety measures.

Normative documents for the smoke removal project:

• Federal law of the Russian Federation of July 22, 2008. No. 123-FZ. Technical regulations on fire safety requirements;
• GOST R 53300-2009. Smoke protection of buildings and structures. Methods of acceptance and periodic tests;
• GOST R 53301-2009. Fire-prevention valves for ventilation systems. Fire resistance test method;
• GOST R 53296-2009. Installation of elevators in buildings and structures. Fire safety requirements;
• GOST R 53299-2009. Air ducts. Fire resistance test method;
• SP 7.13130.2009. Heating, ventilation, air conditioning. Fire safety requirements.

The cost of developing a smoke exhaust project

For each order, we find the most optimal technical solution that best fits into the customer's budget. The cost of designing a smoke exhaust system and you can get answers to other questions by phone 211 11 22 at any time convenient for you, or with the help on-line applications or send an application by e-mail and we will contact you.

Smoke removal automation is a technology for providing buildings and premises with air that does not require significant financial costs. Today, this system causes a lot of controversy among builders and designers of residential, industrial and public buildings and structures. However, they all agree that the principle of automation is the most effective means of controlling the ventilation system and its individual elements (filter, duct, silencer, etc.). Thanks to her, a person does not need to monitor every part of the ventilation, since this function is performed by a computer. This allows you to reduce the staff of the enterprise and reduce the cost of wages to the required minimum. Prevention of accidents and emergencies is also carried out through the automation of dam removal.

The main advantage of automatic smoke extraction is the ability to continuously control the temperature and humidity of the air inside the room. In addition, the system provides for a manual control mode when there is no possibility of working on "autopilot". Another advantage concerns the ability to control the performance of ventilation systems, taking into account specific parameters and environmental factors. An example of this is the presence of people inside a ventilated room, the time of day or season.

The automated smoke exhaust system can have a design of any complexity: from simple supply systems to ultra-modern innovative air flow distribution systems. The latter are even able to track the parameters set by the operator and maintain them at a certain level.

The simplest smoke exhaust systems are built on the basis of control units that are combined with a general communications network or are integrated into existing monitoring and dispatching systems. Their price is low, which determines their quick payback and popularity among designers.

More sophisticated smoke control distribution systems are able to process a huge number of signals using special programmable sensors and modules to collect information. The consumer interface and software are developed taking into account the needs of each specific customer. Such systems have the function of constant monitoring of air temperature and humidity parameters, they also provide the ability to automatically turn on and off the ventilation system, which significantly saves energy resources.

Thanks to the use of automatic smoke removal in one room, several types of ventilation can be installed at once. This is especially important for industrial, industrial buildings, large office or shopping malls. Constant control over all elements of the system is carried out by a computer, which can react to the slightest changes in air flow indicators. This not only does not cause any particular difficulties on the part of the personnel, but also implies significant savings in the payment of energy resources.

Detailed design of a smoke exhaust automation system

I offer you a real project of a smoke exhaust automation system for an administrative building.

Scheme 1: Smoke exhaust automation project
Scheme 2: Smoke exhaust automation project

Modern large industrial enterprises cannot be imagined without smoke exhaust systems. After all, they are considered emergency ventilation systems and provide the necessary conditions in order to evacuate people when a fire breaks out.

A large-scale industrial enterprise cannot do without a smoke exhaust system in modern conditions. Such a system on an industrial scale is one of the elements of fire safety and makes it possible to create acceptable conditions for the evacuation of a large number of people from premises that have been exposed to a fire, at the optimum time.

Design of smoke exhaust and protection systems. Purpose of anti-smoke ventilation.

The main task of the system is to quickly remove smoke and combustion products from the room in the event of a fire. It is especially important to have such systems in areas where there is no free access to fresh air. It is also necessary to remove smoke and combustion products along the route of people during evacuation. At the moment of fire, a complex of engineering systems responsible for safety is activated (fire extinguishing, smoke removal, sound notification, access control, communication with services and other evacuation systems).

Objects where smoke extraction systems are required

To ensure the safety of people, it is necessary to remove smoke in case of fire. in a multi-storey building for any purpose (residential, business center, etc.), office buildings, shopping centers and other places of large gathering of people, on the territory of underground parking lots, in warehouses.

When you need a smoke exhaust system

Systems are necessary in absolutely any building, but their significance is actualized where the movement of people is limited by objective reasons - for example, in prisons, or hospitals, or high-rise buildings with intricate corridors. A sudden outbreak of fire will sow panic, and in the absence of a smoke exhaust system, many people will die just because they did not manage to find the right way out in time.

In such conditions, the smoke exhaust system will provide people with fresh air, concentrate carbon monoxide and prevent smoke from spreading through the premises, interfering with vision and breathing.

Often, the system works in tandem with room ventilation, therefore, when developing the latter, specialists pay attention to the selection of equipment that can continue to work in conditions of smoke and high temperatures.

System advantages

Increased smoke during a fire is one of the reasons for the disorientation of people and, as a result, panic and possible death. Smoke exhaust systems deal with this problem very effectively. In addition, one of their indisputable advantages is the localization of carbon monoxide, which is dangerous to human health and life.

System design principles

The essence of ventilation and smoke removal systems is the same. The only difference is that materials are used to form the smoke exhaust system that ensure its normal functioning at high temperatures. This is achieved by using ferrous metals in their creation. A prerequisite for the installation of smoke exhaust systems is an agreed and approved project.

By the principle of creation, systems are static and dynamic. The static system consists in simply turning off the ventilation system at the moment of strong smoke and, accordingly, stopping the spread of smoke. In this case, there is no installation of smoke exhaust as such, which makes the static system very cheap.

The dynamic principle is considered more effective. The exhaust ventilation system in this case operates alternately to remove unsuitable air from the premises and supply fresh air. With a smoke exhaust system, it is possible to use several fans, each of which has its own function. At the preliminary stage, a technical assignment is prepared, our designers select optimal solutions and prepare a smoke exhaust project for approval.

In some cases, a stand-alone system, used only in emergency situations, may be a suitable option.

Regulations

The regulatory framework (SNiPs, SP, GOSTs) governing the design, installation, testing of smoke ventilation is constantly being improved. Changes and additions are made to the standards, updating these documents for modern realities. The ventilation must comply with all applicable requirements. Otherwise, the first fire check will bring a lot of trouble.

• SP 7.13130.2009: Fire safety requirements. Heating, ventilation, air conditioning
• GOST R 21.1101-2009: Basic requirements for design and working documentation
• SP 60.13330.2012 (SNiP 41-01-2003) - Heating, ventilation, air conditioning
• GOST 21.602-2003: Rules for the implementation of working documentation for heating, ventilation and air conditioning

How smoke ventilation works.

Most effective automatic system... The facility houses sensors and a control panel. If signals from one or more sensors indicate the presence of fire, it automatically opens smoke exhaust valve and the pumping of air from the room begins. There are also systems that are started manually from a central control panel or using special buttons located in easily accessible places.

Smoke exhaust systems equipment

Exhaust implemented in various ways. Smoke extraction fans can force air, which leads to the expulsion of combustion products into the outlet ducts. Also, fans are installed in the ducts and work for the hood. Increased requirements have been set for the smoke exhaust equipment (resistance to high temperatures, reliable operation in extreme conditions, etc.).

Design features

The system parameters are calculated without fail, taking into account all the characteristics of the object. The number of smoke receiving devices, the power of the equipment are determined, the automation is selected, a decision is made on the type of ventilation. Design solutions must necessarily meet the requirements of regulatory documents.

System maintenance

To ensure uninterrupted operation of the system in the event of a fire, maintenance should be carried out regularly. It includes checking the integrity of air ducts, serviceability of valves, fans, sensors and other system elements. Security systems need to be checked for quality of work, measured and updated technical reports, which are presented at the request of the inspector.

In the absence of a project, executive documentation, protocols for checking security systems, the inspection organization can issue fines, issue instructions for eliminating shortcomings, and even close / seal the facility. We recommend that you carry out checks of engineering systems and in advance.

OV project Smoke extraction Production and warehouse base

LLC "Darna" MO, Istra district

System selection

When choosing one or another smoke extraction system, it is highly desirable to be guided not only by economy. The choice should be optimal, first of all, from the point of view of safety - in this case, it is necessary to consult with the specialists of the VeerVent company, who provide professional assistance in the selection and installation of smoke removal systems. In addition to consulting assistance, our employees successfully carry out the installation of these systems throughout Russia.

The company "VeerVent" carries out both the design of smoke removal and installation using certified equipment that meets all building rules and regulatory documents, with subsequent commissioning.
The team of VeerVent LLC is a team of professionals with extensive experience.

Description:

This article provides the basics of smoke control technology with a list of typical preparatory steps for the design of these systems and a list of common design tasks.

Smoke exhaust system design basics

C. E. Magdanz, Project Development Manager, Alvin and Associates, Omaha, Nebraska, USA

The time of evacuation of people from a burning building is calculated by professional firefighters in seconds. Fire flares up quickly, and smoke - also a very serious hazard - spreads faster than fire. The natural reaction to fire is to flee. However, it is difficult to quickly escape from large or high-rise buildings, tunnels and underground structures. Escape from the fire is impossible for physically helpless people, some hospital patients (seriously ill or undergoing surgery), and prisoners. For such cases, smoke extraction systems provide the necessary protection.

This article provides the basics of smoke control technology with a list of typical preparatory steps for the design of these systems and a list of common design tasks.

Terminology

The term “” is used broadly herein as the process involves the use of the physical properties of materials and structures, equipment, and various techniques (alone or in combination with each other) to control and remove smoke. Physical parameters are passive characteristics such as, for example, the smoke permeability of structures. Equipment - fans, openable windows and smoke detectors. Methods - design solutions such as room insulation, smoke removal aeration, mechanical smoke removal system. Room insulation is based on the physical properties of structures designed to prevent the spread of smoke by isolating the fire source. The smoke exhaust aeration system uses separate devices, not connected to the duct system, designed to remove smoke due to the natural pressure difference inside and outside the building. A mechanical smoke extraction system uses equipment (fans, air ducts, valves, detectors) to control the movement of smoke by mechanically creating the necessary pressure differentials. The normal operation of mechanical smoke extraction systems depends on the physical properties of the building structures.

Closely related to smoke extraction is the fire extinguishing task, for which the physical properties of structures (fire-resistant barriers), equipment (sprinklers) and methods (room insulation) are used. The placement of fire-resistant partitions and sprinkler systems is regulated by various regulatory documents, and these documents do not require mutual approval. Thus, fire retardant and smoke-tight baffles are often inconsistent with the zoning of the sprinkler system. An example of an object with coordination of fire extinguishing and smoke removal systems is a building project with an atrium, in which the signal for switching on the mechanical smoke removal system is the flow of water in the pipes of the sprinkler system.

Purpose of smoke exhaust systems

The purpose of smoke exhaust systems is as follows:

Preventing the spread of smoke from the ignition source.

Preventing smoke from entering the escape route (ensuring acceptable conditions for people evacuated from the building).

Providing a microclimate outside the source of fire, allowing firefighting personnel to work normally.

Protecting people's lives.

Protection of property from damage.

This list does not include the creation of normal conditions in the room where the fire source is located, nor does it specify a condition that determines that escape routes and means must be clearly defined and reliably separated from other areas of the building.

Development of smoke control systems

The smoke extraction concept is quite old. As soon as a person first built a hearth in his home, he immediately realized the need for a hole for the release of smoke.

The modern practice of smoke control dates back to the 1940s, when it became apparent that smoke spreads through the air ducts of ventilation systems far beyond the fire source. This predetermined the appearance of fire protection valves and static smoke protection systems.

Smoke dampers and dynamic smoke evacuation systems began to emerge in the 1970s when it became clear that blocking smoke paths in a static smoke control system was at odds with the need to supply fresh air to hospital operating rooms. In operating rooms, supplying clean air to the patient is the first line of defense against infection. When the operation is in progress, it is unacceptable to shut off the supply of clean air, especially when there is smoke in neighboring rooms. For this reason, many operating room air conditioners have been designed to supply 100% outdoor air (assuming no smoke outside).

With certain standards in place, OEMs will be able to specify fan performance at both normal and elevated temperatures in specifications. This will allow designers to select fans taking into account their characteristics both during normal operation and in the smoke exhaust mode.

A useful tool used in the design of smoke exhaust systems is aerodynamics computer modeling. The essence of the numerical modeling method is that the volume of a room is represented in the form of a certain (finite) number of "thin" zones. The ignition source occupies a relatively small number of such zones. The computer is used to solve a set of aerodynamic equations describing the jet flow on a time scale, thus simulating the propagation of smoke. The correctness of the modeling was verified in the course of full-scale field studies. The check confirmed the high accuracy of computer modeling, its usefulness and applicability were recognized. However, since computer simulation is quite difficult, it requires appropriate qualifications to carry it out. The most suitable field of application for computer models is non-standard buildings of complex configuration.

Research is carried out in related fields as well. So, for example, the optimal placement of smoke sensors in rooms and air ducts is determined, the phenomenon of "bridging" is studied in the case of smoke in atriums (when clean air flows through a layer of smoke at a certain location of the exhaust openings), the reliability of protection against smoke of staircases by creating excessive pressure is investigated.

Concerning the prospects for further research, we can point out the problem of maintaining the system's operability. For example, now no protection by means of smoke removal is provided for the places of laying communications. Another issue is the strength and reliability of smoke protection structures (see the sidebar "Smoke protection structures").

Smoke extraction methods

Smoke control and extraction systems can be either static or dynamic. In the presence of smoke in the building, the static method involves stopping all the fans, as a result of which the smoke propagation slows down due to the insulation of the premises when the air exchange stops (the basic method of combating smoke).

In a dynamic system, when smoke occurs, all or some specific fans continue to operate in normal or special mode, creating overpressure areas according to the smoke control scenario. Fans in dynamic systems can be separate to remove smoke and supply clean air for pressurization, or both in sequence.

Dynamic smoke extraction systems can be used alone or in combination with smoke protection barriers. An example of a separate dynamic smoke exhaust system is an air curtain that creates an air flow to prevent the spread of smoke. Smoke extraction systems are more common, the effectiveness of which depends on the reliability of smoke protection structures. An example is an atrium with an exhaust hood (Fig. 1), a staircase with overpressure (see the sidebar "Overpressure in staircases"), overpressure in elevator shafts and shelters, overpressure in sandwich zones (fig. 2). In typical sandwich systems, the ignition floor is in the exhaust zone, and one or two floors on top and one floor on the bottom are in the overpressure zone. Zoning smoke exhaust systems with a single supply unit for all zones are very complex. To simplify installation, commissioning and long-term operation, designers should provide a separate ventilation unit for each zone.

All smoke exhaust systems interact with other engineering equipment of the building, the power grid and fire safety system are of the greatest importance. Since the smoke protection dampers are closed by a fire signal, it is permitted not to install these dampers in the air ducts of the smoke exhaust system, since this system must work during a fire. However, this exclusion does not apply to fire-retardant dampers, which must be installed in the air ducts of the smoke extraction system at the points of passage through fire-resistant partitions.

It should be noted that many elements related to smoke protection are not controlled by the HVAC engineer.

It is very important for the designer of a mechanical smoke exhaust system to coordinate his work with other specialists in order to ensure the reliability and correct placement of the protective partitions, to check the power supply of the equipment, communication with the fire alarm and fire extinguishing system. The correct functioning of the gas fire extinguishing system can be impaired by the operation of the smoke exhaust system, since the air movement required for smoke removal can lead to a decrease in the gas concentration to a level insufficient to extinguish the fire.

Smoke exhaust systems equipment

Equipment for smoke removal systems can be both special and general purpose. Special equipment is used only in the presence of smoke. General purpose equipment is typically used for other HVAC needs and also serves to remove smoke in the event of a fire.

Special smoke removal equipment, as a rule, is not replaced during the life of the building, it is always used in the same way, in accordance with its intended purpose. Specialized equipment is relatively easy to operate as it serves a single purpose. However, such equipment requires a special place and regular maintenance, since its reliability depends on it. Examples of special equipment are fans for pressurizing stairwells and for extracting smoke from atriums.

Regular maintenance of general equipment is due to its daily use; the building does not need to take up extra space, since the same equipment is used for different purposes. At the same time, there are a number of disadvantages - the complication of regulation due to multifunctionality, the possibility of accidental damage to the smoke exhaust system during the reconstruction or renovation of HVAC systems. An example of the use of HVAC equipment for smoke removal systems is a supply fan of an air conditioner to create overpressure in zones in a sandwich system.

Structures in which smoke extraction systems are usually used are high-rise buildings, prisons, hospitals, covered markets, underground structures, transit tunnels. Premises inside buildings with the need to install these systems - atriums, escape stairs, elevator shafts, shelters, theater stages, smoking rooms.

Preparation for design

1. Familiarize yourself with the requirements of regulatory documents and the wishes of the customer, which determine the need for the installation of smoke removal systems. The regulations provide the minimum required requirements. Customers sometimes make demands in excess of the required minimum, especially when it comes to protecting property.

2. If it is anticipated that a smoke exhaust system will be required in this facility, check it against the regulations. (If you believe an alternative solution is possible, be prepared to discuss this issue.) Regulations generally allow for different design approaches. Once the need for a smoke exhaust system has been established, select the appropriate options and options.

3. After choosing the design principle, check it with the normative documents and discuss the procedure for acceptance tests. Sometimes the acceptance test method can influence the design choice.

4. When designing a system, strive for its possible simplification. In the future, the customer will have to serve it as vital for the building.

5. Remember that system testing and fire drills will be the first stress on the system. Consider weather conditions when thinking about drill scenarios. If the heat exchanger freezes during a real fire, this is not a problem, but during a drill it is unacceptable.

6. Do not forget that the purpose of regulatory documents is to protect people, while the designer's task is broader. The project requires the development of a cost-effective system that meets both customer and regulatory requirements. For the designer, this can be a trade-off task.

7. Keep minutes of all discussions and decisions made. Using all the design documentation, draw up a diagram of the interaction of the smoke exhaust system with other HVAC systems.

Design problems

Since the placement of fire-resistant partitions has a significant impact on duct routing, they should be placed before drawing up a detailed ventilation scheme. Changing the location of these partitions later can become a very big problem for the designer of the smoke exhaust system. An example is the situation with a sandwich system where a fire-rated partition divides rooms on the same floor. Moving the baffles can entail reworking the air distribution, especially if a separate air handling unit is used for each smoke zone.

The only reliable method for full-scale testing of a smoke exhaust system is to create a source of hot smoke. Since this is practically impossible, cold smoke is usually used in tests. Thus, the real test of the efficiency of the smoke extraction system is postponed until a fire breaks out, which, fortunately, is rare. And due to the rare possibility of full-scale testing, the improvement of smoke removal systems, supported by serious arguments in favor of the new technology, lags behind everyday HVAC systems (heating and cooling).

Since the design principles for flue systems can vary and are rarely testable in reality, educating standards officials, planners, architects and building owners is challenging and challenging. And since the leading developers of smoke exhaust systems are HVAC engineers, they must also become leaders in the process of training other specialists.

Smoke-tight structures

The integrity of smoke-tight structures may not be ensured in the following difficult situations:

1. Building codes often do not explicitly indicate when smoke-tight ceilings (smoke barriers) should be made. There are only indirect indications of this - the requirement for the installation of smoke protection valves.

2. If the regulations specify the installation of smoke barriers, this most often coincides with the requirement to install fire-resistant partitions (fire barriers). However, the production of flame retardant devices under development with independent testing laboratories usually only gives certification for fire resistance and temperature. Even if some of the manufacturers in their laboratory tests these devices for tightness, building codes currently do not require or recognize certification of smoke barriers for this indicator.

3. When ducting through fire-rated partitions, it is usually necessary to install fire-retardant valves (although there are some exceptions). However, if this fire barrier must also be smoke-tight, few manufacturers can provide complete fire / smoke dampers that have a certified leakproof perimeter seal. In fact, many valve specifications do not include a perimeter seal as the seal can interfere with thermal expansion of the valves. However, many local regulatory authorities require contractors to install a seal on the valves despite the specification variance.

4. Flame retardant devices are tested in laboratory conditions, which often do not correspond to reality. For example, some piping systems exhibit significant thermal elongation (displacement), and all piping is subject to displacement due to seismic loading. In tests by independent test laboratories, pipelines are rigidly attached to fire barriers; this means that in real conditions the pipelines must be rigidly attached to each crossed fire-resistant partition. When asked if the seal is elastic, the valve manufacturer says yes. When asked how elastic it is, he answers “more than 25%”. When asked what is the thickness of the sealant layer, he answers "1 cm". Thus, the physical value of the permissible displacement within the elasticity of the seal is 3 mm, which is less than the normal elongation of the steam line of a not very long length. In the absence of a rigid attachment of each steam line or condensate line to each fire-resistant partition, the first time the system is used, either the thermal insulation of the pipe or the flame protection device will be damaged. Some specialty industries (such as the manufacture of computer microcircuits) use ideas such as rubber gaskets (of the same type found on the gearbox levers of front-wheel drive vehicles) to keep smoke out of fire-rated baffles.

Overpressure creation in stairwells

Although this article does not provide a detailed explanation of the method of creating overpressure in staircases, it must be pointed out that for multi-storey buildings with many doors leading to the stairs, the creation of overpressure is a problem.

An overpressure of 12 Pa gives a load on a 0.9 x 2 m door of about 2 kg. During fire and smoke, the position of the doors leading to the staircase differs from the usual one. A good design should define how much pressure needs to be maintained for smoke protection separately for most doors closed and most doors open situations and how the overpressure will affect the effort required to open the doors. Assuming that the automatic control is working properly, uniform overpressure in a high staircase can be ensured by supplying air at several places. Do not forget to provide a place for routing air ducts to a variety of air inlets.

Some local codes allow simpler solutions to be used instead of pressurizing stairwells. These include natural ventilation or smoke-free ventilated shelters.

Reprinted with abbreviations from ASHRAE magazine.

Translated from English by O. P. Bulycheva.

The calculation is carried out on the basis of methodological recommendations to SP 7.13130.2013 "Calculated determination of the main parameters of smoke ventilation

1. When calculating systems for removing smoke from open rooms for various purposes (halls) and atriums, the designers assume that the minimum width of the room is underestimated. In some cases, this affects the determination of the area of ​​the fire site and, as a consequence, the performance of the smoke control ventilation system decreases.

2. Making a mistake when selecting a fan for a smoke exhaust system: designers forget to bring the calculated static pressure of the fan to standard conditions. This can be done using the formula:

_____________________________________________ Psv = 1.2 * (PsmN + Pd) / ρsmN

Where P smN is the static pressure in front of the fan (based on the calculation result) at the temperature of the flue mixture;
P d - resistance of air ducts and elements that do not take part in the calculation when determining P smN;
ρ smN is the density of the smoke mixture at its temperature

3. When selecting the fan according to the graphs, there is a confusion of total and static pressure. The calculation determines the static pressure. And the manufacturer's nomograms are made for full pressure. In this case, a fan with a reduced performance is selected.

4. The bottom of the exhaust smoke ventilation valve must be higher than the escape door opening.

5. The damper of the compensating smoke exhaust system should be located in the lower part of the room. As a rule, at a distance of 500 mm, so as not to interfere with the cleaning of floors.

6. The use of an exhaust smoke ventilation system without a supply compensating ventilation system is unacceptable.

7. Air imbalance during anti-smoke ventilation is not more than 30%.

8. Determination of the flow rate of the compensating supply air supply to compensate for the smoke exhaust system must be performed according to the mass flow rate (unit kg / s).

9. When smoke ventilation is in operation, the pressure drop across closed doors (especially evacuation doors) should be no more than 150 Pa. Otherwise, an adult will not open the door, and what can we say about children.

10. When designing smoke exhaust systems for corridors, it is imperative to take into account the corridor configuration, see clause 7.8.

11. When designing a smoke ventilation system for staircases of multi-storey buildings of type H2, it is possible to divide into zones (device of several valves) to reduce the pressure on closed escape doors.

12. The removed combustion products must be thrown out at a distance of at least 5 m from the place where the outside air is taken from the supply smoke ventilation.

13. If the roof and walls are made of combustible materials, then the discharge of combustion products must be carried out at a height of at least 2 m from the level of the roof, otherwise, protection with non-combustible materials should be provided.

14. It is not allowed to install general smoke ventilation systems for premises for various purposes. For example, if the joint venture requires smoke removal from the meeting room and the corridor, then it is necessary to design two separate systems and it is prohibited to combine them.

15. When providing back pressure in the safe areas, it is necessary to take into account that the supplied air must be heated. As a rule, an electric heater is chosen.

16. In front of the fans of anti-smoke ventilation systems, it is necessary to install motorized check valves (normally closed fire-retardant valves with a reversible drive) in accordance with clause 7.11, clause 7.13, clause 7.17. If the valve is located outdoors, the valve must be electrically heated. It is worth paying attention to the fact that the installation of a gravity check valve is a violation of clause 7.19. Since this valve does not maintain its position when the power supply is turned off.

In conclusion, I would like to add that the calculation and design of fire ventilation systems should be carried out by professionals. You can always contact our company for advice on smoke removal and air pressure systems, as well as order a project.