What a smoke control damper is - and isn’t.

Smoke Control Dampers play a vital part in the integrity of Smoke and Heat Control Systems. They are installed into the smoke shaft wall at high level in the corridor or lobby and are controlled automatically to open or closed positions. On receiving a fire signal, the smoke control system fully opens the Smoke Control Damper on the fire floor to exhaust smoke, while all dampers on all other levels remain closed to resist the passage of fire and smoke.

Smoke Control Dampers used with Powered Smoke and Heat Exhaust Systems must, therefore, be able to fully open to allow the extract of smoke and heat and remain closed to maintain compartmentation. Smoke Control Dampers used in this situation must be tested as multi-compartment Smoke Control Dampers and are designated as suitable by the addition of a suffix ‘multi’. In addition the symbols ‘i – o’, ‘ o – I’ or ‘I – o’ indicate whether the damper has been tested from inside or outside or both. To be a multi-compartment damper they must be tested and certified as ‘o-I’.

Smoke Control Dampers must also demonstrate integrity ( E )and insulation ( I ) in the closed position and be classified in accordance with EN 13501-4 Fire classification of construction products and building elements – Part 4 Classification using data from fire resistance tests on components of smoke control systems. The insulation and integrity of a Smoke Control Damper should match the fire resistance of the wall into which it is being installed. In the certification, it is declared as ‘EI’ followed by the number of minutes to which it is tested. For example, EI120 declares that the Smoke Control Damper is tested for integrity and insulation for 120 minutes and may be used in a 2-hour fire compartment wall.

Smoke control dampers must be tested for durability to demonstrate its operational reliability over the life of the system and this is determined by opening and closing cycle tests in accordance with EN 1366-10 Fire resistance test for service installations – Part 10 Smoke Control Dampers. Where Smoke Control Dampers are used only for smoke control or within a combined smoke control and environmental systems, they must demonstrate their suitability with the addition of C300 or C10,000 where the number of tested cycles is indicated.

If Smoke Control Dampers are to be used in the vertical and/or horizontal installation into a wall they must be tested in this orientation and given the classification of ‘Vew’ and ‘How’ to demonstrate compliance.

Smoke control dampers must resist the passage of Smoke under pressure and this performance is also described in EN 1366-10 and classified as ( S ). The addition of ‘500’, ‘1000’ or ‘1500’ indicates the suitability of use under these pressures in Pa.

In addition, the Smoke control damper must also remotely signal both its open and closed position and move to those positions within 60 s of receipt of a signal. The addition of ‘AA’ indicates the automatic activation of the damper by actuators with strength and durability when subject to tests in EN 1344-10.

The Construction Products Regulation (CPR) came into force in July 2013 and introduced a mandatory requirement on manufacturers to only place products onto the European Union market which comply with relevant harmonised standards. BS EN12101 is the certification which covers all smoke and heat control systems.

The testing process for all smoke control products includes Notified Body Third-Party Accreditation, ongoing Factory Production Control, and traceability of all products through the manufacture's system.

Demonstration of compliance with the CPR involves the manufacturer issuing a Declaration of Performance (DoP) for each product. As these products are life safety equipment, they must be tested to an Assessment & Verification of Constancy of Performance (AVCP) Level 1. This means that the manufacturer must appoint a Notified Body accredited to the relevant part of EN12101 to issue the manufacturer with a certificate of constancy of performance. This allows the manufacture to issue the DoP.

The certificate of constancy of performance will include, type testing of the product, initial inspection of the Factory Production Control, continuous surveillance, and assessment and evaluation of the Factory Production Control. The DoP will contain information about the essential characteristics of the product. These characteristics will indicate the suitability of the product for the required function.

For Smoke Control Dampers, demonstration of their suitability for installation into specific situations is given within the DoP and as an example EI 120 (Vew – I – o) S1500 C10000 AA multi would allow the damper to be installed vertically in a wall of fire resistance of 120 minutes with smoke leakage resistance suitable for a multi-compartment smoke extract system. In addition, it has the durability to be used for environmental control and is operated by actuators giving accurate feedback on their open and close position.

There is concern that uncertified and wrongly certified products are still being promoted and installed in Powered Smoke and Heat Exhaust Systems. Dr Barbara Lane in her report Grenfell Tower Phase 1 Report Appendix J Lobby Smoke Control – requirements and provisions clarifies that the lower test BS EN 1366-2 is a standard for natural smoke ventilation systems due to the lower pressures applied in the test and further confirms that the dampers used in Grenfell were neither certified fire dampers nor smoke dampers. She further clarifies the certification by referring to BS EN 12101-6 Smoke and Heat Control Systems – Part 6 Specification for pressure differential systems – Kits which states

‘if different pressurized or depressurized zones are connected to the same fan or set of fans by a common system of ductwork and/or shafts, smoke control dampers shall be used'.

In summary, designers and specifiers need to be aware of requirements for Smoke Control Dampers. Only Smoke Control Dampers, tested to BS EN 1366-10, classified in accordance with EN 13501-4, and certified to BS EN 12101 - 8 Smoke and Heat Control Systems – Part 8: Smoke Control Dampers can be used within Powered Smoke and Heat Exhaust Systems