Fire dampers should be installed where ductwork or air transport systems pass through fire-resistance-rated walls, floors or partitions. Their role is to maintain the fire compartmentation of the building. When a fire occurs and the damper closes, it helps to prevent flames, hot gases and smoke from spreading through the opening created by the duct or pipe.
In practice, this means that every penetration of a fire compartment by a duct or transport system must either be sealed in a fire-resistant way or protected with a correctly selected and installed fire damper.
Fire dampers and fire compartments
Most modern building regulations are based on the concept of fire compartments. A fire compartment is a part of the building designed to contain a fire for a specified period of time. Walls, floors, ceilings and doors forming the compartment boundary have a defined fire resistance, such as EI 60 or EI 90.
Whenever a duct or transport line passes through this boundary, it creates a potential weak point. If the penetration is not properly protected, fire and smoke can bypass the compartmentation and spread quickly. The fire damper is installed in or close to this penetration and designed to close when a fire is detected, so that the overall fire resistance of the boundary is maintained.
Typical locations for fire dampers
Typical installation locations for fire dampers in buildings include:
- where ventilation or air-conditioning ducts pass through fire-rated walls between fire compartments
- where ducts pass through fire-resistant floors between storeys
- where process air or exhaust ducts from industrial equipment penetrate fire-resistant partitions
- in shafts and risers where ducts run vertically through several fire compartments
- at the interface between fire compartments and technical rooms, plant rooms or filter units
In each case, the designer must consider the fire strategy for the building, the required fire resistance of the barrier and the specific conditions for the duct or transport system.
Who decides where a fire damper is required?
The final responsibility for deciding where fire dampers are required normally lies with the fire safety designer and the building owner, within the framework of the applicable building regulations. The designer will:
- analyse the fire strategy and compartmentation of the building
- identify duct and transport penetrations through fire-rated barriers
- determine where a fire damper is necessary or where alternative protection is acceptable
- specify the fire resistance, type and installation conditions for each damper
Installers must then follow the design and the product documentation. Any deviation from the documented installation conditions should be clarified with the designer and the supplier.
Special systems such as pneumatic conveying
In industrial plants, there are often additional systems where material or air is transported under pressure or vacuum between compartments, for example pneumatic conveying lines, dust extraction and process air systems. These systems can also create paths for fire and smoke spread if they pass through fire-rated walls or floors.
In such cases, a standard HVAC fire damper may not be suitable. The damper must be selected for the medium (air, dust, powder), pressure range and possible explosion risks, and it must still meet the fire resistance and installation conditions required by the building regulations and the project design.
How FireSep fire dampers fit typical installation locations
FireSep fire dampers are intended for installation where air or pneumatic material transport passes through fire-resistant barriers, for example in ductwork, process air systems or compressed-air conveying lines. The dampers are CE marked in accordance with CPR 305/2011/EU and manufactured in compliance with EN 15650. Fire resistance is documented through testing in accordance with EN 1366-2 and classification in accordance with EN 13501-3, based on tests performed by DBI.
For each damper type and configuration, FireSep provides product documentation describing the permitted installation situations, such as wall and floor types, allowed orientations, sleeve and fixing details and perimeter clearances. This documentation helps designers and installers ensure that the installed damper is used within the scope of the documented testing and installation conditions, and that it can be included in fire safety solutions designed and documented in accordance with the Danish Building Regulations (BR18).