A Fire Dampers guidance document (NAAD22) was published in 2022, clarifying the responsibilities of building owners and occupiers in relation to fire dampers in their buildings, in addition to those of their HVAC system suppliers. There is evidence to suggest, however, that of an estimated 100 million fire dampers in UK buildings, many are still not meeting regulatory requirements. The delay in meeting compliance is a problem for all existing UK building stock, but there is a particular urgency for those with responsibility for healthcare estates. This is because sites such as hospitals are designated as Higher Risk Buildings under the Building Safety Act 2022. This entails additional responsibilities, which need to be addressed by both organisations and designated individuals.
This article reviews the ways in which fire dampers are employed in health estates, provides details of the requirements now in place for compliance with the Building Safety Act 2022, and offers practical guidance for the selection and installation of fire dampers in buildings such as hospitals, care homes, and medical centres.
Fire dampers: an overview
Fire dampers are installed in the ductwork of heating, ventilation, and air-conditioning (HVAC) systems to isolate and prevent the spread of fire. Buildings are divided into fire compartments. Central air supply is usually managed by air-handling units, and every room is connected with a duct for supply and extract air. The ducts run horizontally and vertically through the entire building, passing through different fire compartments — see Figure 1.
A method to prevent the passage of smoke and fire from one compartment to another must be provided wherever the duct passes through a fire compartment line. Fire dampers are installed in walls or ceilings with resistance to fire, to provide protection. When a rapid rise in temperature occurs, the fire damper is activated to close. As shown in Figure 2, without a fire damper in place, fire and smoke is able to spread rapidly through the ducts into other fire compartments.
As highlighted in Figure 3, in normal use, the fire damper is held open by a fusible link. When the temperature across the fusible link reaches 72°C, the blade is released and a mechanical spring closes the damper blade. Fire dampers with motorised control (actuated) are also widely used. To prevent the spread of ‘cold’ smoke transferring through the duct (smoke generated by the fire before the 72 °C release temperature is reached), fire dampers can be supplied with a spring return actuator (fail safe close), which will close the damper upon activation signal from the fire alarm panel (smoke detector).
Use of fire dampers is extremely widespread in UK building stock. In 2021 BSRIA estimated that around 146,000 mechanical curtain dampers and 70,000 motorised dampers are installed every year. These are for new-builds and replacements, which account for just 1 per cent of the annual market, indicating that the total number of dampers already installed in UK buildings could be as high as 100 million.
Employer’s responsibility
Since the introduction of the Regulatory Reform (Fire Safety) Order 2005, it is the employer’s responsibility to maintain its fire safety systems. In order to comply, damper testing should be carried out annually as a minimum. A fire damper test requires a visual inspection of the damper, and an activation or a drop test. Complying with testing procedures can be problematic, however. Everyday maintenance and minor adaptations — such as an electrician drilling a hole in a wall to run a cable, can impact on fire damper compliance as a fire wall could be breached, undermining the fire and smoke compartmentalisation strategy. Wear and tear (for example airborne contaminants) can also compromise the effectiveness of fire dampers.
A number of British Standards are in place with regard to fire dampers. These define: the performance of the fire dampers themselves; testing of fire dampers (particularly during the design of the units); installation methods according to the supporting construction, and classification of units to make product selection clearer for specifiers. There are new harmonised product standards for each of these issues:
- BS EN 15650: Ventilation for buildings — Fire dampers, which defines basic performance and requirements for fire dampers. This provides the mechanism for conformity marking against the Construction Product Regulation (CPR) 305/2011, and sets out the requirements for factory production control, documentation, and labelling, as expected from an AVCP 1 system product.
- BS EN 1366-2: Fire resistance tests for service installations — Part 2: Fire dampers, defining the standards that fire dampers must be tested to, including essential characteristics like (integrity (E), insulation (I), and leakage (S) of the fire damper, when installed in, on, or remote from, a supporting construction.
- BS EN 15882-2: Extended application of results from fire resistance tests for service installations — Part 2: Fire dampers, governing effective installation and guidance where buildings are adapted.
- BS EN 13501-3: Fire classification of construction products and building elements — Part 3: Classification using data from fire resistance tests on products and elements used in building service installations: fire resisting ducts and fire dampers. This is used by the Notified Body to collate all test data, and provide the final classification against the essential characteristics, for each installation type, within the criteria defined.
Building Safety Act compliance
Importantly, requirements placed upon individuals with responsibility for buildings incorporating fire dampers have been redefined in recent years. Dame Judith Hackitt’s independent review following the fire at Grenfell Tower (Building a Safer Future, published in May 2018) contributed findings which have been incorporated into the new Building Safety Act, which became law in April 2022. A significant amount of secondary legislation has been introduced since that time, and guidelines specific to fire dampers were published in the National Association of Air Duct Specialists guidance document (NAAD22). This document (covering design, selection, installation, and maintenance of fire dampers) is available for free download at https://www.naaduk.co.uk/naad22-guidance-document-app/.
The reforms to existing legislation have changed the way in which custodians of buildings must think, both during design and after construction of buildings. There are important updates for buildings of all types, with specific additional responsibilities for Higher-Risk Buildings (HRBs). This category encompasses buildings more than 18 metres in height, or with at least seven storeys. Hospitals, care homes, and buildings containing at least two residential units also fit within this category. HRBs were required to be registered with the Building Safety Regulator by 30 September 2023. Since 1 October 2023 all new-builds categorised as Higher-Risk Buildings must to be registered with the Building Safety Regulator prior to occupation. The testing regimes for fire dampers are dictated by the categorisation of the building involved, with additional responsibilities for those designated as Higher-Risk.
Dutyholders’ increased responsibilities
Firstly, under the Building Safety Act 2022, responsibilities have increased for all Dutyholders — for example individuals and organisations that commission, design, construct, or refurbish buildings. Those involved must now go beyond the requirements of the Construction (Design and Management) Regulations (CDM), ensuring that projects are not only safe to build, use, and maintain, but also that they are safe to occupy.
Secondly, the Act introduced the role of Accountable Person, referring to individuals/organisations that own, or have responsibility for, buildings during occupation, as well as those responsible for the repair or maintenance of common parts of a building — for example corridors and lobbies. Therefore, responsibility falls on Dutyholders to select ‘adequate and proper materials’ that are ‘appropriate for the circumstances in which they are used’, and to integrate these within the building design to facilitate them to be ‘applied, used, or fixed, so as to adequately perform the functions for which they are designed’. This must be achieved while ensuring that routine inspection and maintenance throughout the lifetime of the building can be achieved.
In addition to reviewing damper types, NAAD22 provides guidance on minimum regulatory requirements for routine maintenance, testing, and inspection, of installed dampers. It also covers installation, testing, and commissioning, of dampers during initial installation, as well as considerations for the correct design for, and selection of, fire dampers. Some key areas to study are the requirements relating to system design and damper selection, and the importance of detail and quality of workmanship during installation.
As an example, the person designing and selecting the fire dampers should understand:
1. The principles of compartmentation.
2. The standards and principles for testing FDs and SCDs.
3. The applications of FDs and SCDs.
4. The correct procedures for the selection and installation of FDs.
5. Building services spatial coordination.
6. The correct procedures for access to, regular testing, and maintenance etc of, FDs.
7. The importance of good behavioural and ethical competence.
Involve manufacturers at an early stage
Recognition is given that the required knowledge may not be held by a single party, and thus the involvement of a manufacturer at the early stage of design — who can support the Dutyholder with respect to the certified applications of the dampers, is recommended.
In the case of a new-build, once the building has been designed for compartmentalisation, and the damper is being selected, the type of supporting construction into which the damper is to be installed is crucial. The manufacturer must provide a Declaration of Performance (DoP) and Installation & Operating Manual (IOM) to the Dutyholder, specific to the supporting construction. The material structure of the wall itself is crucial. Without both of these documents, there is no guarantee that the installation will meet the required performance.
Failure to install a fire damper in accordance with the manufacturer’s IOM, without obtaining permission for an installation deviation, will render the fire damper non-compliant, with responsibility to underwrite the installation falling on those involved in this design decision.
Changes to building use
After installation, changes to building use which might impact the required damper classification are also critical, as they could void the original installation compliance. For example, if a change in use results in a fire damper protecting an escape route, a fusible link fire damper would need to be changed to a motorised fire damper.
The important thing to remember when specifying and installing fire dampers is that it’s not about the ductwork; it’s all about the walls or floors. When identifying the correct product and determining how it needs to be installed, you need to ascertain details of the compartment element as follows:
- Structure type.
- Installation location.
- Fire stopping execution/material.
- Fire integrity requirement.
- Connecting duct shape = damper model.
Check these project specific installation details against the documentation available from the fire damper manufacturer, ensuring that you are able to obtain a Declaration of Performance (DoP) and Installation & Operating Manual (IOM) specific to the specific supporting construction.
Dutyholders are required to ensure that ‘The fire damper shall be installed and sealed as in practice in a supporting construction in accordance with the manufacturer’s instructions’. For every application, the installation method (specified by the product manufacturer in the IOM) must be followed. The IOM needs to employ the same installation method and materials as those used in the fire test.
Technical support
Given the important role played by these products, and the comparative complexity of the requirements for Building Safety Act 2022 compliance, engagement with the fire damper manufacturer at an early stage is crucial to achieve compliance. Manufacturers with well-established and accredited fire protection laboratories are likely to be the best placed when a health estate project involves numerous types of supporting construction.
Trox, for example, has a modern fire protection laboratory, the International Centre for Fire Protection Technology (ICB) (in Neukirchen-Vluyn in North-Rhine-Westphalia in Germany), and has developed its range of fire dampers for a wide range of supporting constructions encountered in modern buildings — from solid walls and floors to lightweight partition walls (metal and wooden stud), solid wood / CLT walls and floors, sandwich panel walls, asymmetric shaft wall, ribbed concrete, composite ceilings, and hollow deck, among others. This has resulted in 3rd party Notified Body testing and certification of over 400 damper installations.
Trox supplies four fire damper variants to meet the requirements of varying system designs, all of which conform to the harmonised product standard (BS EN 15650), have been tested to BS EN 1366-2 / BS EN 15882-2, and classified for integrity (E), insulation (I), and leakage (S), to BS EN 13501-3. We can assist those specifying dampers by providing proven, declared performance within an extensive range of supporting constructions, and with multiple penetration seal options. The full accompanying installation details for the specific applications are available, and specifiers and contractors can be provided with the information necessary to ensure accurate selection and installation of Trox fire protection dampers. This is essential to enable those designated as Dutyholders or Accountable Persons to achieve and maintain regulatory compliance, and to safeguard building safety.
For those needing to extend their knowledge of compliance issues, Trox has developed training seminars on fire damper and smoke control damper testing, classification, and installation.