Ensuring compliance in smoke ventilation life safety systems

This feature looks to reiterate the importance of using fully compliant life safety products and outlines the steps being taken to improve industry awareness.

Accurately determining whether or not a life safety product or system is fit for purpose is crucial in maintaining the highest levels of protection in buildings. Despite this, compliance for smoke vents has proved to be somewhat problematic since the introduction of the BS 7346-1 standard in 1990 and its replacement EN1210102 in 2003.

Part of the problem stems from the fact that evidence of compliance is not commonly available for specifiers and building owners, making it difficult to determine if the life safety product used is fit for purpose and compliant with the standard.

Use of NSHEVs

Whilst clarification was provided in 2013 by mandating the 2011 Construction Products Regulation within the UK and the 2017 Grenfell Tower tragedy resulted in several initiatives being proposed and implemented, we still see non-compliant smoke vent applications installed and a lack of accurate product information remains a key contributor to non-compliant life safety products being placed onto the market.

For many years the use of windows for life safety smoke ventilation (commonly called AOVs or NSHEVs) has been common practice. In residential high-rise applications NSHEVs naturally exhaust smoke from common escape routes (corridors and escape stairs) to aid means of escape and provide smoke-free access for firefighting personnel. They are also utilised to bring in replacement air to stairs and common corridors to balance pressure, especially as part of a mechanical extract smoke ventilation system. In non-residential applications, life safety smoke ventilation systems utilise NSHEVs predominantly in atria applications for natural smoke extract and replacement air intake to aid means of escape. They also provide replacement air intake as part of a mechanical atria smoke extract system. 

Natural smoke extract shafts are seen in both residential and non-residential applications where NSHEVs are utilised at the head of the shaft to exhaust to atmosphere in addition to the head of the escape and firefighting stairs.

An NSHEV is a single product that generally comprises two components: the ventilator and actuator that automates it. To comply, both components must be tested together as a single product at an accredited test facility to all declared annexes of the standard. It must also be manufactured/completed under a third-party audited factory production control (FPC) process. 

NSHEVs generally fall into three distinct categories:

• Vertical intake and extract ventilators
• Inclined intake and extract ventilators
• Horizontal intake and extract ventilators

Understanding, application and evidencing of compliance relating to these products has, in general, been poorly applied and policed, resulting in increased risk to the building occupants should a non-compliant product fail as they attempt to exit the building. A large contributor to this issue is the accuracy and consistency of sales and marketing collateral, which can often be misleading, resulting in ill-informed procurement and sign off decisions.

Consistency and accuracy

In response, The SCA has put in place an initiative to ensure that all of its members’ commercial collateral relative to EN12101-2 and window actuators is consistent and accurate, more recently producing a document which provides information on natural smoke and heat exhaust vents (NSHEVs) usage, methodology and, importantly, compliance/certification requirements.

The applicable part of EN12101 for an NSHEV is part 2, the 2003 version being harmonised in the EU therefore utilised within the UK construction market. Whilst the UK has now left the EU, harmonised European Norms (hENs) remain a requirement and products must be suitably certified. Compliance to hENs within the construction industry, especially within the field of life safety smoke ventilation is improving; however, lack of awareness and at times ignorance still contributes to non-compliance.

Like other SCA guides, the NSHEV guidance document bridges design guides, legislation, product certification, product application and best practice. It is an informative guide for all stakeholders involved throughout the lifecycle of a building during all RIBA stages and for clients and organisations that inherit buildings who are accountable to maintain their life safety systems under mandatory legislation.

Assuring performance

Regardless of the certification requirements by region, smoke ventilators utilised for life safety means of escape should be certified to EN12101-2: 2003, with the proof of compliance being the Declaration of Performance (DoP).

The completed and certified NSHEV on site should comply with the initial type tested sample with an audit trail in place to prove the correct manufacturing and completion processes have been followed. 

The DoP should declare all essential characteristics for the NSHEV aligned to its application and regulatory requirements. An actuator fitted to a window is therefore non-compliant unless the two products have been tested together to the annexes of EN12101-2, completed under a third-party audited FPC process, placed onto the market via a DoP and certified aligned to the market upon which the NSHEV is being placed.

To meet this requirement all SCA members have formally agreed to only install certified smoke ventilation products in addition to attaining SDI-19 third-party audited smoke ventilation specialist installer Certification.

The SCA has also agreed a procedure to address misleading or inaccurate documentation and information regarding NSHEV compliance and will act or forward the information to Trading Standards for further action should the offending company fail to address the issue. 

Committed to compliance

The SCA is committed to the continual improvement of life safety compliance within the industry to ensure legislation is upheld and building occupants are safe. The new document provides an overview of NSHEVs and offers insight into their application, performance requirements and the certification route to compliance, serving as a much-needed reference for the industry.

To download the free SCA guidance document ‘Guidance on Smoke and Heat Exhaust Ventilators. Applications and the use of Actuators and Ventilators’, please visit the SCA website.

For more information, go to www.smokecontrol.org.uk