DW/145 – the new Guide to Good Practice for the Installation of Fire and Smoke Dampers – addresses the practicalities of damper system design and installation. Peter Rogers reports.
It is only in the past few years that those working with fire and smoke dampers have had universally accepted guidelines to follow. The turnaround began in 2007 when the Association for Specialist Fire Protection (ASFP) published the Grey Book as an industry guide to design and installation. The Ductwork Group of the HVCA collaborated in the Grey Book's production and continues to support its content, but created DW/145 to address the practicalities of system design and installation.

The guide clarifies the matters that must be addressed when fire and / or smoke dampers are to be installed within a building's ventilation ductwork system. It brings together the disciplines involved in the overall process, from specification and damper manufacture to a compliant installation.

It is the responsibility of all team members to ensure they recognise and understand all aspects of the process from design to handover, or run the risk of contributing towards a non-compliant installation. A client-appointed Construction Design and Management (CDM) co-ordinator oversees the process from design through to installation.
The initial responsibility for ensuring a compliant installation lies with the design office and the final responsibility with the on-site fitter.

As well as the importance of the type of fire-separating element / barrier in which the damper is to be mounted, there are three main design criteria to be met:

(i) The installation should meet the system design specification with regard to its fire classification.
(ii) The damper should be installed in accordance with the manufacturer's tested method.
(iii) The damper should be fixed either within or directly adjacent to the fire-separating element / barrier and be supported independently of the connecting ductwork.

Key activities and responsibilities to be considered for the project are:

· Fire / smoke compartmentation - Fire strategy drawings indicating fire and smoke compartmentation, the type and classification of the fire barrier and its construction.
· System specification and design - Designs must consider access during installation, and current and future maintenance inspections required by legislation. System specifiers and designers submit a proposal to the building control and / or fire authority for approval, incorporating a tested damper arrangement.
· Compliance with Building Regulations - Either E and / or ES criteria. The method of installation must have been successfully fire tested by an independent body on behalf of the damper manufacturer.
· Damper specification - Size, type, installation method and accessories required must be specified, ensuring that the requirements of the building control authority and fire officer are met.
· Damper assembly selection - Including dimensionally detailed guidance on how the damper assembly is to be installed and any requirements for damper unit expansion.
· Programmed activity sequence - A sequenced installation programme of activities must be provided.
· Fire-separating elements / barriers - A designated team member ensures fire barriers and penetration accommodate damper arrangements specified in the agreed design.
· Penetration seals - It is imperative that the penetration seal system is as tested by the damper manufacturer.

DW/145 places emphasis on engineering solutions being project specific and not generic specific.

System design must be project-specific and based on the fire strategy of the building. The system designer is responsible for defining and specifying all aspects of the installation, from damper location to final inspection, and compliance with current Building Regulations.

Damper manufacturers will provide dimensionally detailed guidance on how the damper is to be installed, including any requirements for expansion. Once selected, it is imperative that this guidance is adhered to.

The system designer should make all team members aware of the design, to query any aspect that could result in the installation of a non-compliant damper. Appendix D of DW/145 lists these considerations in detail.

All of the manufacturer's testing information must also be available. For a full list of technical information see section 4.3 and appendix G.3.1 - 8 of DW/145.
The damper fitter should check the operation of the damper before installation so that any malfunction can be corrected. Any substitution or deviation must be approved by the design office to avoid a non-compliant installation.

The design office must liaise with the designated principle contractor to ensure a practical sequence is established that allows all parties to complete each element of the installation.
Following installation, the damper fitter and installation supervisor carry out pre-handover checks to ensure the installation is compliant. These include checking the dampers are clean and free from damage, ensuring all internal and external control devices are accessible and in good condition, verifying the dampers are installed the correct way up relative to the airflow access, making sure the damper blades can be reset via the access panels in the adjacent ductwork connections, and confirming the damper has been left in the open position.

The installation must be formally handed over to the CDM co-ordinator for final inspection, who records the report in a register that is retained by all interested parties.

· DW/145 can be purchased online at www.hvcapublications.co.uk , by calling 01768 860405, or by e-mail from hvcapublications@welplan.co.uk

• Peter Rogers is chairman of the HVCA Ductwork Group