Smoke Extraction and Ventilation Ducts: The Unsung Heroes of Fire Protection

In building safety, fire protection systems are like silent bodyguards, and smoke extraction ducts and fire-resistant ventilation ducts are crucial for protecting people from the harm of fire and smoke. It should be noted that in a fire, the most terrifying thing is often not the fire itself, but the smoke! When thick smoke and toxic gases fill the air, visibility is completely obscured, the air becomes unbreathable, and escaping becomes extremely difficult. Moreover, high-temperature smoke can accelerate the spread of the fire. Therefore, a well-designed duct system is not just a casual installation; it is a matter of life and death!

Chapter 1. Smoke Extraction Ducts: Racing Against Smoke

The task of Smoke Extraction Ducts (SED) is clear: quickly extract smoke during a fire to buy time for people to escape, facilitate firefighters’ rescue efforts, and prevent flashover.

When are they most needed?

• Large spaces (such as shopping malls, office buildings): Smoke spreads rapidly, quickly reducing visibility.
• Parking lots (especially low-ceilinged ones): Smoke sinks at an alarming rate, quickly blocking escape routes, which is extremely dangerous.
• High-rise buildings: The stack effect can accelerate the upward spread of fire, causing significant trouble.
• Spaces with high ceilings (over 15 meters): Automatic sprinklers are less effective, making smoke extraction crucial.

What are the rigid design requirements? (According to European standards)

• High-temperature resistance: Whether equipped with fans or not, ducts must withstand the high-temperature smoke generated during a fire. If the duct is located within a fire compartment, its fire resistance should be comparable to the fire intensity in that compartment. This is the most basic requirement.
• Maintaining performance when passing through firewalls: When ducts need to pass through firewalls, the fire resistance of the penetrating part must be as strong as that of the wall . This prevents fire and smoke from spreading through the ducts.
• Not to be designed casually: Smoke extraction is not just about installing a few pipes. It requires careful analysis of fire size, space dimensions, smoke descent speed, etc., to ensure that escape routes remain visible in critical moments.

Chapter 2. Fire-Resistant Ventilation Ducts: Safeguarding Fire Compartments

Fire-Resistant Ventilation Ducts (FRVD) are mainly used to ensure the integrity of fire compartments, preventing fire and smoke from spreading from one compartment to another through the ducts.

The importance of fire compartment integrity: The fire resistance of a building depends on whether each fire compartment (composed of firewalls, floors, and doors) can remain stable, fire-tight, and heat-insulating for a specified period (such as 30, 60, 90, 120 minutes). Ducts and other components passing through fire compartments must not compromise this integrity.

European practices vary: European countries have different views on the risk of smoke spread through ventilation systems:

• Some countries consider the risk of smoke spread through ventilation systems to be low.
• However, many countries require that if a ventilation system serves multiple fire compartments, automatic smoke and fire dampers or fire/smoke dampers must be installed where the ducts pass through fire compartments.
• In some regions, there is more flexibility; fire dampers are not mandatory as long as safety goals are met.

The main point is: Ducts passing through fire-resistant components must themselves be fire-resistant. Ordinary galvanized iron ducts are inadequate because:

• They are prone to softening and deformation in a fire.
• They may become rapid channels for fire and smoke, accelerating the spread of the fire.
• They do not meet internationally recognized fire safety standards.

Chapter 3. New Materials: Better Than Steel

Faced with complex building structures (ducts passing through multiple compartments, varying functional area requirements) and harsh fire conditions, selecting the optimal duct system is extremely challenging. JOINBLING^®, a leading Chinese innovator, has broken through the limitations of traditional steel ducts and provided better solutions. 

The rise of self-supporting fire-resistant duct systems:

• Core materials: High-performance calcium silicate boards (such as professional flre calcium silicate board) are used. These materials inherently possess excellent fire resistance, moisture resistance, and dimensional stability.

What are the advantages?

• Duct systems: Including fire-resistant wrapped steel duct systems and self-supporting fire-resistant duct systems.
  • Single-layer structure, lightweight yet rigid: Easy to transport and install (can be prefabricated on-site or in factories); in some cases, supports do not require additional fire protection.Good performance: Aerodynamic performance (airflow, leakage rate) is close to that of high-quality steel ducts, and the surface roughness coefficient (affecting resistance) is comparable to that of steel.Durable: Moisture-resistant and weather-resistant.Certified: Passed tests according to international standards such as EN 14306, with fire resistance ratings ranging from 30 to 120 and even 180, and bearing the CE mark.Large size: Laboratory-certified for use in large-scale projects.
  • Flexible: Can be combined with mineral wool or gypsum boards for sound insulation and thermal insulation, and can also be used to upgrade the fire resistance of existing steel pipes.

Advanced calcium silicate board self-supporting systems represented by JOINBLING^® offer excellent fire resistance, simple design, strong engineering applicability, and authoritative certification. They are an excellent choice for many buildings today, especially those pursuing safety and sustainability. They not only comply with regulations but also protect people’s lives and property.

Conclusion: Preparedness Before a Fire is True Safety

For buildings, smoke extraction and fire-resistant ventilation ducts are not just cold building materials, but precisely calculated and strictly regulated components that act as barriers to protect people during fires. Understanding their functions, using innovative materials, and complying with standards mean practicing “prevention first, life first” in building design and use. Choosing the right duct system is like adding an insurance policy to the building, keeping potential dangers at bay.