Proper smoke ventilation in a building is not only essential for saving people’s lives in the event of a fire, but it is also regulated strictly by law. Automated Opening Vents – also known as AOV – are an integral part of this system.

Simply put, automatic opening Vent is a system which is used to vent air or smoke in a building and is used in both natural and smoke ventilation systems. The devices help to avoid smoke build up inside a building, which aids both occupants and fire rescue personnel who have entered the building to put out the fire.

This system is integrated into a complete smoke or natural ventilation system, where components work together to clear the building of smoke in the case of an emergency. These are often positioned at the highest point in a smoke shaft, or at the top of an escape route. This allows a path for the smoke to travel up and out of the building.

The automatic opening vents are opened upon detection of fire, which happens via smoke detectors which are usually fitted on every floor of a building. When the fire is detected, these devices, along with any other doors or louvers, will open automatically, thus playing their role in the removal of smoke from the building.

It is possible for fire fighters to override the systems if necessary, however. If this happens, the override facility is placed at several manual call points around the building, which can be used by fire personnel to control the fire in the way they see fit.

All the manual call points are mounted to a central control system, which is powered by mains power. Due to the importance of the AOV system, there is often battery back up to ensure that in the case of mains failure, the smoke ventilation system will be able to deploy and protect the occupants of the building from fire.

As can be imagined, the timing of the opening of the vents is very important. For this reason, Automatic Opening Vents open rapidly once a fire has been detected, meaning that building occupants have the best chance of escaping quickly.

In addition to stairwell AOV and smoke shaft AOV, there may also be automated opening windows which also assist in clearing smoke from a particular place. These again will be deployed upon detection of smoke by the smoke detection systems that the building has in place.

In addition to the mechanical nature of the system, the evacuation of smoke from the building is also designed around the nature of hot gases. Smoke and other hot gases are naturally buoyant, which means they will rise automatically to the highest points in the building. It is for this reason that the automatic opening vents and other vents are placed here.

As the hot gas rises automatically, it travels out through the opened events which were activated when the smoke was first detected. As it is the heat, smoke and any other toxic gases that pose a significant health risk, this risk is drastically reduced when they are drawn out of the building through the open vents.

In addition to this, it is necessary for replacement or “make up” air to enter the building at lower points to provide the rising thermal current that is necessary to help hot gases and smoke rise to the top of the building. For this reason, windows and doors many open automatically at the bottom of the structure at the same time as the AOVs open.

With 90% of fatalities in a fire caused by smoke poisoning, there is little doubt of the need for efficient systems like these to help save lives. Automated Opening Vents are just one component of a system that has to power to drastically reduce the danger of fire in any building.