AOV System Smoke Control From Colt

What is an AOV (Automatic Opening Vent) system?

Smoke ventilation systems in buildings often use AOVs (automatic opening vents). Smoke vents have an automated opening and closing system. A central control panel activates this system when it detects smoke.

How do Automatic Opening Vents Work?

When you turn on the smoke ventilation control system, it opens the automatic vents to let smoke out of the building. If they did not do this, smoke could start gathering in different parts throughout the building.

Smoke ventilation has obvious benefits for anyone still in the building. It improves visibility and reduces the levels of harmful toxic smoke, gases and toxins. This increases the chances of a safe escape dramatically.

Smoke vents assist in safe evacuation for individuals and facilitate quicker access for firefighters to the building and the fire. Additionally, they help minimize the risk of smoke inhalation.

They not only have cleaner air to breathe, but they also experience a drastic improvement in visibility. Firefighters need good visibility to navigate unknown buildings quickly and efficiently. We usually place automatic opening smoke vents on roofs to keep people safe. They are installed in areas like stairwells, lobbies, corridors, or other escape routes.

Types of Automatic Opening Vent

AOVs can come in the form of glazed or insulated casement, louvred or ‘flap’ ventilators with controls taking the form of:

  • A spring to open magnetic release (with manual reset)
  • Electric actuators or
  • Pneumatic controls

View our range of automatic opening smoke vents:

Coltlite highly insulated natural louvred ventilator

Colt AXS natural flap ventilator

Colt EN-Seefire

View our full range of smoke ventilation products here.

When do you need automatic opening vents in your building?

Find more information and guidance on designing smoke control systems in England and the related regulations in the resources below.

The most common types of buildings where AOVs could be required are:

  • Large single-storey buildings, such as factories and warehouses
  • Shopping centres
  • Multi-storey Residential buildings
  • Other multi-storey buildings with a fire fighting shaft, generally over 18m tall
  • Buildings with atria
  • Car parks where smoke and fume extraction is required

To determine the exact requirements, seek specialist advice due to differences in building layouts, heights, location, etc.

However, in England, smoke ventilation requirements for multi-storey residential buildings change with height. The below image provides a simple overview of this. Similar, but not identical requirements exist in Wales, Scotland and Northern Ireland.

Fire Safety Standards and Building Regulations

Find more information and guidance on designing smoke ventilation systems in England and the related regulations in the resources provided:

Automatic opening vent maintenance

Properly maintaining smoke vents after installation is critical to ensure their functionality and compliance with the law.

A competent person must service AOVs annually to comply with RRO and BS: 7346-8 requirements.

Additionally, they should undergo testing on a weekly, monthly, and 6-monthly basis. The weekly and monthly checks can be done by someone who knows the system, like the Responsible Person. However, the 6-monthly tests must be done by a certified smoke control specialist. Colt is an example of a certified smoke control specialist who ensures that everything is following the rules.

If any of the vents are found to be non-functioning during routine testing, or have become damaged, immediate action needs to be taken to remedy the faults and/or failures. The local fire service also needs to be notified within 24 hours of the fault being discovered, along with a remedial plan.

If it is not possible to repair or replace the faulty components immediately, the "Responsible Person" should carry out a risk assessment to determine if any additional measures should be put in place until full performance is restored - these might include putting in place a waking watch or relocating the building occupants or employees until repairs can be carried out.

For more information on AOV maintenance, read our blog.

Talk to us about automatic opening vents.

Whether you need to design and install or maintain a smoke ventilation system with AOVs, Colt can help. Talk to us about your requirements by emailing us at or calling us on 02392 451111.