In modern architecture and building technology, smoke control pressure systems and smoke extraction systems play a crucial role in ensuring the safety of human lives and minimizing damage to buildings in the event of a fire. These technical systems are designed to control smoke spread within buildings and keep escape routes clear by efficiently extracting smoke and directing it outside.
Smoke and Heat Exhaust Systems: Types and Functions
The smoke and heat exhaustion system is based on the principle of natural smoke extraction through openings in the roof or facade, utilizing thermal buoyancy. This keeps the building as smoke-free as possible in the event of a fire while also aiding in heat dissipation to relieve the building structure. The main purpose of smoke clearance is to ensure adequate visibility conditions for personal safety, while heat dissipation supports building preservation and firefighter safety during extinguishing efforts.
Types of smoke and heat exhaust systems:
Natural Smoke Exhaust Systems
Mechanical Smoke Exhaust Systems
Smoke Differential Pressure Systems
Garage Smoke Exhaust Systems
Elevator Shaft Smoke Exhaust Systems
Heat Exhaustion Systems
Natural or mechanical smoke exhaust systems create smoke-free layers in the event of a fire, supporting the following functions:
Self and assisted evacuation of individuals through improved visibility and breathing conditions.
Interior firefighting operations by enhancing visibility, facilitating faster orientation, rescue, and fire suppression.
Property protection by reducing heat stress and smoke spread, safeguarding buildings and facilities.
Protection against operational downtime by enabling quicker fire control and reducing the risk of prolonged interruptions.
In large ventilation systems aimed at smoke dilution, although heat stress is reduced, smoke spread increases. Smoke Differential Pressure Systems (RDA) can protect and keep areas such as stairwells free from smoke intrusion. Opened heat exhausts only become effective in later stages of a fire, but they prolong the resistance time of the building structure by dissipating energy. Each of these systems requires specific products and individual design considerations.
Smoke Control Pressure Systems
Smoke control pressure systems, also known as "smoke and heat exhaust systems" , are an important component of fire protection in buildings. They are used to increase pressure in stairwells and escape routes in the event of a fire to prevent smoke gases from entering these areas. By creating positive pressure, smoke is prevented from entering these spaces, improving visibility and keeping escape routes clear for people. Smoke control pressure systems are legally mandated in many countries and must be installed and maintained in accordance with national building codes and standards.
The following describes the operation of an SCPS in the event of a fire:
Step 1: A fire starts in a unit, causing the apartment door to open and smoke or fire gases to enter the escape route. Residents flee to the stairwell.
Step 2: Smoke detectors detect the fire and activate the SCPS, or a manual call point is activated. The control panel responds.
Step 3: The following functions occur simultaneously: The supply air fan draws in fresh air and directs it into the escape route. The actuator in the roof area fully opens the window to expel smoke outside. The air in the escape route is thoroughly flushed with fresh outdoor air. The alarm siren sounds, the strobe light flashes, the door closers are de-energized, and the doors close automatically. The ventilation switches are deactivated.
Step 4: After the flushing phase, pressure control is activated to build positive pressure. Once the fire hazard is eliminated, the system can be returned to monitoring mode. After the alarm has been triggered, all non-safety-critical functions are deactivated.
Smoke Extraction Systems
Smoke extraction systems are specialized systems developed to efficiently remove and dissipate smoke in the event of a fire, facilitating the safe evacuation of individuals. These systems can be either mechanically or naturally ventilated and are deployed based on the specific requirements of a building or application. Mechanical smoke extraction systems use fans to extract smoke from a building and direct it outside, while natural smoke extraction systems rely on the principles of natural ventilation by venting smoke through specific openings in the building.
Positive Pressure Systems for Smoke Gas Control
Smoke gases not only pose the greatest danger to fleeing individuals in the event of a fire but also endanger rescue forces and impede their work.
Systemair's electronically controlled positive pressure systems provide a reliable and tested safety solution in case of a fire. Our systems not only support self-evacuation but also offer additional protection to emergency responders from smoke gases at high fire temperatures. They ensure clear visibility conditions and enable emergency responders to reach the fire source more quickly.
Depending on the requirements, various systems for smoke dilution and smoke clearance in stairwells are employed.
Mechanical Smoke Extraction Systems
In the event of a fire, swift action is crucial to ensure the safety of human lives and minimize damage to buildings. Effective smoke extraction plays a crucial role in improving visibility, keeping escape routes clear, and facilitating access for emergency responders to the fire source. A proven method for smoke extraction is mechanical smoke extraction systems, which are utilized in various buildings and applications.
Operation of Mechanical Smoke Extraction Systems
Mechanical smoke extraction systems utilize fans or blowers to efficiently extract smoke gases and hot air from a building and direct them outside. These systems can be installed in various areas of a building, including stairwells, escape routes, halls, or underground parking garages. They are activated once smoke or heat is detected by smoke detectors or fire detectors.
Advantages of Mechanical Smoke Extraction Systems
Rapid Smoke Extraction: Mechanical smoke extraction systems enable rapid and efficient removal of smoke gases from a building, improving visibility and keeping escape routes clear for individuals.
Protection for Emergency Responders: By removing smoke gases and hot air streams, these systems provide additional protection for emergency responders involved in firefighting efforts.
Damage Minimization: Effective smoke extraction helps minimize damage to buildings by limiting the spread of fire and smoke.
Regulatory Compliance: In many countries, mechanical smoke extraction systems are legally mandated, especially in public buildings, high-rise buildings, and parking garages, to ensure the safety of individuals in the event of a fire.
Design and Requirements
The design of MSES is carried out according to DIN 18232-5. Smoke extraction fans must meet the requirements of VDMA standard sheets 24177 and 24180 and have a suitability certificate. They must be temperature-resistant and elastically connected to the duct network. In the event of smoke extraction, the activation of the fan, bypassing of monitoring elements, and operation at the designed speed must be ensured. Regulation, for example, via frequency converters, is possible for ventilation operation.
Maintenance and Repair
Smoke extraction systems must be regularly maintained to ensure their functionality in the event of a fire. The maintenance intervals are based on the manufacturer's specifications. It is important that the systems are regularly inspected and tested to detect and rectify any defects or deficiencies at an early stage.
Smoke Extraction Systems: General Regulations
For all smoke extraction systems, the requirements of the DIN 18232 series and EN 12101 apply. The design should be coordinated with fire protection experts, authorities, and the fire department during the planning phase. There are specific requirements for components such as ventilation dampers, smoke extraction fans, and ducts. These must be fire-resistant and appropriately certified. Special solutions for smoke zone formation, such as for door areas, are possible and are explained in technical regulations.
The installation and maintenance of smoke control pressure systems and smoke extraction systems are subject to strict regulations and standards to ensure that they function properly in case of emergency. These regulations vary depending on the country and region but may include aspects such as minimum performance requirements, installation, maintenance, testing, and certification of systems. It is important for architects, engineers, and building operators to familiarize themselves with the applicable regulations and ensure that all systems are designed and operated in accordance with applicable standards.
Heat Extraction (HE): Functions and Protection Objectives
Heat extraction (HE) refers to wall or roof surfaces that open automatically above a specified temperature, for example, by melting thermoplastic materials, to divert the heat from the burning room to the outside. Through this process, energy is removed from the fire area, preventing or delaying further heating, particularly of load-bearing or separating components. In this way, heat extraction can extend the load-bearing capacity of components or reduce the required fire resistance of these components.
Heat extraction is used to divert fire heat from a fire compartment to the outside when desired or required. In some special building regulations, such as the Model Industrial Building Directive, the installation of heat extraction surfaces is either generally required or demanded when expanding fire compartment areas. An increase in heat extraction area can also lead to a reduction in the fire resistance requirements of load-bearing or separating components. Ideally, heat extraction surfaces should be placed in the roof or upper part of the wall.
Conclusion
Smoke control pressure systems and smoke extraction systems are essential components of fire protection in modern buildings and play a crucial role in the safety of human lives in case of fire. Through proper planning, installation, and maintenance of these systems, architects and engineers can maximize building safety and minimize potential risks in the event of a fire. It is important for all stakeholders to comply with applicable regulations and standards and to work closely with qualified professionals to ensure that these systems function properly and can be effectively used in case of emergency.