Automatic Smoke Vents – How do they Operate?

As part of a building fire safety system, it may be essential to have automatic opening vents. These automatic smoke vents are often required as part of buildings regulations, making it safer for people in the event of a fire. Automatic systems are the best type of vent to install, as they will open automatically and begin to vent out smoke immediately. They are often used in commercial and communal residential buildings, like blocks of flats, especially when there is only a single stairway.

What is an automatic opening vent? 

An automatic opening vent, or AOV, is a smoke ventilation system that is used to remove smoke. It’s an important part of the fire safety system, as smoke is actually a bigger killer than fire itself. Choosing an AOV is an important decision for anyone in charge of a building.

An AOV is fitted into the roof and may be used in more enclosed spaces, like stairwells or smaller rooms. This is where smoke inhalation could become detrimental very quickly, and where people are more likely to need some assistance. The AOV will be activated and will open up immediately, venting out the smoke to reduce buildup inside the property.

It is also useful for fire safety teams and firemen. Clearer air gives them better visibility, so they can rescue the people inside the building who require help.

How does an AOV system work? 

An AOV will usually be placed at the highest point of an escape route, and also a smoke shaft. There should be smoke detectors and manual control points spread across the building – usually one on each floor at least.  When an alarm is set off in a specific point within a building, this will then cause the smoke vent to open. A control panel is used to control the vents, as well as the fire alarm system. The vents can also be wired into a building management system, controlling all vents from one point.

The control panel should come ready to install and to be wired into the system. A good control panel will use LED indicators to show that the vent is working correctly, and will have a break glass panel. These can then be networked to control various automatic smoke vents around the building.


Even if buildings regulations don’t specify smoke vents for your particular building, it is something that many buildings have installed anyway. Talk to your building planner if it is a new build. Later down the line, you can get in touch with a supplier of smoke vents, who will be able to give you more information. They can provide a survey to see where smoke vents should be fitted and then, if you choose to go ahead, can also install the vents.

AOVs are complex systems that require a thorough understanding of buildings and fire regulations. Make sure you fully understand what is required for your building before choosing to progress. Contact the relevant bodies and conduct your own research into how an automatic smoke vent might work for you.