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January 22, 2021


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Smoke control

Fire Protection: Your Complete Guide to Smoke Control Systems, Regulations and Building Codes

In this guide, you’ll learn the smoke ventilation regulations and guidelines, understand how to determine the standards for smoke ventilation and discover how to choose the correct smoke ventilation systems for your building.

What is smoke control? And what are smoke ventilation systems? 

What is a smoke control system?

A smoke control system is a mechanical structure that essentially controls the movement of smoke in the event of a fire, preventing it from spreading through a building. Smoke control systems are designed to protect the people inside buildings and ensure firefighting personnel can access the premises without suffering smoke related injuries or complications.

SmokeControlAssocation-smoke-20As a critical life safety system, it is vital that smoke control solutions are installed and maintained by a competent person with the necessary expert knowledge in order to ensure optimum performance should a fire break out in the building.

What are the types of smoke control and smoke ventilation systems?

Dedicated smoke control systems include natural extractions (which don’t require a power source as they are triggered by hot smoke’s innate buoyancy) and mechanical extraction systems (which use powered fans). AOVs (Automatic Opening Vent) are a popular type of natural smoke control system – they are activated to open by either a smoke detector (which is triggered by hot smoke’s innate buoyancy), or a manual alarm.

Other types of smoke control systems include atrium exhausts, opposed airflow and smoke reservoirs.

What is the difference between a smoke control system and a smoke clearance system?

Smoke control systems are different to smoke clearance systems. Smoke control systems work to limit the spread of smoke during a fire, whereas smoke clearance systems help ventilate smoke after a fire has been extinguished.

How to choose the correct smoke ventilation system for your building

How do you know which type of ventilation system is best for your building

The type of smoke ventilation system you procure will depend on the type of property you’re trying to protect. Different buildings require different levels of smoke control management, and you have a legal obligation to ensure the utmost safety. Typically, multi-story buildings, factories, warehouses and malls will require specialised systems.

For example, in a large single-story warehouse, a fire is able to spread much faster than in other buildings. This comes down to the large size of the compartment – smoke is able to rise quickly into the roof space, spread laterally, and then when the roof space is full, start to ‘build down’. Importantly, “the rate at which this occurs varies according to the nature of the combustible contents and the geometry of the building. In an unventilated situation, a building with a volume of 10,000m3 can become smoke logged in just a few minutes.”

On the other hand, industrial and manufacturing sites might need industrial ventilation systems, which dilute air full of contaminants with fresh air, and they collect and remove any dust or smoke that pose a risk to a building’s occupants. In the event of a fire, these harmful toxins could be spread in the smoke. Likewise, industrial and manufacturing sites are additionally prone to harmful toxins in the air. As a result, industrial ventilation systems protect individuals from contaminant, are economically efficient, provide quality control to the air, and boost air quality.

On the other hand, in flats and maisonettes, smoke containment in communal areas and escape routes will be significantly important, especially if the building is several storeys high, to ensure that firefighting personnel can successfully undertake their responsibilities.

When correctly installed, smoke control systems should keep escape and access routes free of smoke, facilitate firefighting operations, reduce the risk of the fire developing further and protect the building’s contents from smoke damage.

Smoke ventilation guidelines, regulations and standards

How should smoke vents be tested?

Smoke control systems should be maintained every six months to ensure all parts are performing and functioning to the highest standard. Typical maintenance of a smoke vent should occur regularly. For Automatic Opening Vents, smoke detectors should be tested with a telescopic smoke testing unit, and in doing so, their sensors will test the AOVs. Every 12 months, smoke detectors should be cleaned to prevent contamination and false alarms.

An important test you’ll need to consider is mitigating AOVs trap hazards when closing. As we explore in our article ‘Smoke control systems – typical maintenance issues’: “To ensure that motorised AOVs do not present a ‘trap hazard’ when closing, switches adjacent to them have to remain depressed to keep the closing operation going. In other words, the mechanism must stop as soon as the switch is released. This configuration is known as mitigating the risk of the trap hazard to a passing occupant. All AOVs within 2.5m of floor level must have some form of ‘mitigating procedure’ or safety device fitted and checking these forms part of the inspection.”

After inspecting AOVs in action, they should be assessed for wear and tear, and fixed where needed. You could also add a repeater panel to your smoke vents, which will signal a green, amber or red light depending on whether any faults are present.

A suitably qualified installer should be used to fit smoke control and ventilation systems, and should be experienced in fire strategy verification, system design, installation and commissioning in accordance with the relevant industry standards.

Read more about installation standards in this guide from the Smoke Control Association.

What are the building regulations for fire safety, installing smoke vents and automatic opening vents?

Constructing, renovating or even maintaining a building comes with a handful of responsibilities. Fire safety is of upmost importance, and you need to adhere to the correct building regulations to prevent injury or death.

How should official documents influence how you choose and install your smoke ventilation systems?

Building regulations outline the minimum requirements you need to pay attention to. When it comes to fire safety and smoke control systems, there are four main regulations you need to be aware of.

1) FIRE SAFETY – Corresponding building regulation: Approved Document B

  • It is mandatory to install fire detection systems and fire alarm systems. These must provide instant identification of a fire, as the sooner action is taken to contain the fire and evacuate or inform those inside the building, the higher the chance of safety.
  • Secondly, Approved Document B outlines that you must provide multiple fire exits or routes out of the building and into fresh air – known as ‘means of escape’. Only in exceptional circumstances is it adequate to have one fire escape.
  • In order to ventilate smoke from a corridor or lobby, Approved Document B also outlines that if an external window is located on the external wall, an AOV can produce effective smoke ventilation. However, developers often use external walls for scenic window views, in which case, a vertical smoke shaft can be used (provided it has an automatic opening smoke shaft).
  • Approved Document B also outlines that basements should have one or more smoke outlets.
  • In the wake of the Grenfell Tower fire, the Ministry of Housing, Communities and Local Government published a new clarified version of Approved Document B, primarily updating the language to plain English and restructuring its guidance.

2) SMOKE CONTROL AND VENTILATION – Corresponding building regulation: Approved Document F

  • This outlines the types of acceptable smoke ventilation systems for different buildings, depending on their size, type and the number of people who would need to evacuate in the instance of a fire and the how floors above ground level are reached (stairs, elevator etc).
  • Usually, more than one AOV (Automatic Opening Vent) is required to effectively reduce the level of smoke inside the building. This is especially true for stairwell ventilators – as the build up of heat and smoke can inhibit access for firefighters and also injure or kill residents.

3) CONSERVATION OF FUEL AND POWER – Corresponding building regulation: Approved Document L

  • According to the regulation, smoke vents should have a U-Value of 3.5 W/m2.K or lower.
  • The better-insulated something is, the lower its U-Value will be. Approved Document L regulates the amount of excessive heat loss smoke vents have, and how much thermal insulation they should provide.


  • The smoke vents you procure to install in any building must comply to BS EN 12101, and AOVs must be CE marked to meet this regulation.
  • BS EN 12101 standards are only given to products after they undergo a series of rigorous tests.
  • In the event of a fire, this standard ensure that the AOV system can be trusted to perform its role in removing smoke from the building.

Visit the IFSEC Global Directory to compare smoke ventilation systems.


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