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What Is An AOV & Do I Need One For My Business?

If you’re managing the safety elements for a business, office space, residential unit or shopping centre, you’ve probably come across the term ‘AOV’, but what does it actually mean and how does an AOV make your building safer?

We’ve put together a complete guide on AOVs so you can determine what will work best for you.

What does AOV mean?

AOV is an abbreviation of ‘Automatic Opening Vents’ designed to help ventilate and extract smoke from buildings during emergencies and in the event of a fire.
Unlike some systems, AOV roof lights don’t remove smoke mechanically but naturally, by allowing smoke to leave via roof openings that are triggered by detectors or fire alarms.

How does an AOV work?

AOV systems are generally coupled with an alarm or detector system to work in the event of a fire. During an emergency, a detector will trigger an AOV to automatically open.

The main objective of an AOV is to help remove smoke and heat from a building, particularly common usage space where residents may be trying to escape, or in office spaces where the majority of staff are housed for example.

During the design and construction phase of a building, Automatic Opening Vents are applied to create shafts and fire fighting lobbies which can be used by fire crews, helping to manage and tackle fires more effectively. In most cases, both common usage space and fire fighting lobbies are designated in the same area.

Mechanically, AOVs are operated by actuators which, when triggered by a detector, will raise the roof light to a predetermined, optimised angle, to allow for maximum natural ventilation.

What are the benefits of an AOV?

Using AOVs reduces the amount of smoke and heat contained in a building during a fire. Firstly, this benefits residents or workers inside, as they are likely to inhale less harmful smoke during evacuation.

As the design and operation of AOVs makes use of convection, an enhanced visibility is created when an AOV is present in a smoke situation, as the smoke and heat is allowed to rise, leaving lower levels more clear than they would be without ventilation.

‘Flashover’ is also reduced; the situation in which heat is drawn back down into a building as natural air flow encourages regulation of heat throughout the building.

Aside from increasing life protection, AOV’s also reduce the financial impact of a fire, simply by allowing smoke to exhaust, resulting in lower overall building damage.

What are the different types of AOV?

Single Units

An R2 AOV is a standalone unit which can be insulated or un-insulated for use in either heated or unheated situations, such as smoke shafts.

Xtralite single units have an opening of 140 degrees, which allows for optimum natural ventilation.

Louvred Vents

Louvred vents aren’t typically designed for heated spaces, as they aren’t insulated. However, they can be added to preformed upstands and work on roof pitches up to 90degrees, meaning they are versatile and can be used on a number of installation projects.

Louvred, covered vents are also applicable on end of corridor situations to reduce opening risk.

What sort of buildings use AOVs?

AOVs can be found in a multitude of buildings and designs, including single stair blocks in flats, common escape routes of larger flat blocks, enclosed car parks, shopping areas, office blocks and office common escape routes and basement areas.

Where can are AOV’s used?

There are four main situations in which AOVs are employed

Stairwell AOV

Stairwells make use of AOV roof lights or louvres to promote natural air flow and remove smoke through convection.

End of Corridors

AOVs can be used at the end of corridors, by employing louvered components which increase safety and minimise day to day risk.

Bottom and side hung AOV windows can also be used.

Smoke Shafts

Smoke shafts couple roof lights with doors to exhaust heat and smoke.

BRE Smoke Shafts

BRE smoke shafts are generally deployed in buildings over 18m & provide a smoke shaft adjacent to fire fighting shafts / stairwells.

Do You Need AOV for Your Business?

Commercial and multiple occupancy buildings are required by law to provide clear escape routes, free from smoke to allow residents or workers unimpeded escape, as well as provide first responders and fire crews access during an emergency.

Want More Information?

Download our 'Case For Natural Smoke Ventilation in Fires' PDF for more information and technical information on all AOV's.