What is an AOV?
AOV is simply an abbreviation for “Automatic Opening Vent”. An AOV system is a control system designed to vent air or smoke for use in natural & smoke ventilation.
So why do I need an AOV system?
AOV control systems are used mainly to control the ventilation of smoke in a fire. Changes to building regulations were made due to the results of investigations into smoke inhalation.
When a detector or call point is triggered an AOV control system will open actuators, windows or vents to create ventilation. This clears smoke for people leaving the building and vents smoke out of the area that has been triggered. The provisonal standard that is now available for reference is EN:12101.
What AOV products do I need?
We supply 2 systems for AOV control; AOV single zone or AOV multi zone. Each panel can be triggered by detectors or VCS call points. This will then activate actuators to open or close.
How do I decide which AOV system to fit?
You first need to decide what items you need to control on your system. You should work out how many items will need to open separately & then class each one as a zone. See the following examples:
Example 1 :
You have one roof vent or window which must open when the fire alarm is triggered.
In this situation you have 1 zone. You need to first see how the roof vent or window operates. If it is manual opening then you will need to add an AOV actuator which can be triggered to open or close. If there is already a fire system in place there may be smoke detectors fitted. In this situation you can link an AOV single zone to your fire system which will trigger when smoke is detected in that area. The AOV actuator when triggered will open, when reset it will close. VCS yellow call points can be added for override or system test. (If there is no fire system in place a detector can be fitted to trigger the system.)
Example 2 :
You have 4 floors, a window on each, and a vent for a shaft on the roof.
This situation would leave you with 5 zones. Here you would use an AOV multi zone panel which will be able to open/close each zone independantly. Under this condition it may be that the vent should open together with any zone that is triggered. (A roof vent will be on a smoke shaft or stairwell. Opening it together with a window will then create a chimney effect clearing smoke.)
In this case you can set the AOV multi zone with zone 1 as a “master”. A simple solution that will then trigger zone 1 together with any of the zones 2 – 5.
Again you would then need to add an actuator to each window/vent and either link to your existing fire system or add VCS call points & smoke detectors to the AOV multi zone system to trigger.