When it comes to fire safety, most people immediately think of alarms and sprinklers. However, in a fire emergency, the most significant threat to life isn’t actually the heat; it’s the smoke.

 This is where an AOV (Automatic Opening Vent) becomes a building’s most critical line of defence.

At Meritas, we believe life-safety systems should work seamlessly with a building’s architecture. While fire dampers protect a property’s structural integrity, AOV systems are the primary tools used to manage smoke, ensuring escape routes remain clear for occupants and visible for fire and rescue services.

What is an AOV?

An AOV is a motorised fire safety device designed to help smoke and heat escape from a building. These vents are typically installed in strategic locations such as:

• Stairwells
• Lift shafts
• Corridors

The primary goal of an AOV is to maintain “tenable conditions”. Because smoke is often more lethal than heat, these systems are critical for providing a safe path for evacuation.

How AOV Systems Function

The operation of an AOV is both sophisticated and reliable. The process generally follows a specific sequence:

1. Detection: A smoke detector or manual call point sends a signal to a dedicated control panel.
2. Activation: The panel triggers electrical actuators.
3. Ventilation: The actuators automatically open the vents to a specific, tested angle to allow smoke to escape.

Types of Smoke Ventilation

Depending on the building’s complexity, AOV systems are categorised into two main types:

• Natural Smoke Ventilation: These use the natural buoyancy of hot gases, allowing smoke to rise and exit through roof-mounted vents or windows.
• Mechanical Extract: In complex structures, an AOV may work alongside powerful, balanced fans to actively pull smoke out of the building.

Compliance and British Standards

Navigating the regulatory landscape is essential for any building owner. To ensure safety and reliability, all AOV installations must comply with the BS EN 12101 series of standards. This rigorous testing ensures that vents, actuators, and power supplies can withstand the extreme pressure and temperature differentials present during a real fire.

Furthermore, the Building Safety Act 2022 has introduced a heightened emphasis on “industry competence”. It is no longer enough to simply install a vent; the system must be meticulously integrated into the building’s wider fire strategy.

The Importance of Maintenance

Even the most advanced AOV is useless if it fails during an emergency. Under the Regulatory Reform (Fire Safety) Order 2005, the “Responsible Person” has a legal duty to maintain these systems.

Specifically, BS 9999 dictates that smoke control systems require regular functional testing. During a maintenance check under BS 12101, we verify:

• Actuator Power: Ensuring actuators have sufficient power and signal response.
• Reliability: Confirming vents open fully and reliably.
• System Logic: Verifying that other levels achieve “lock-out” as intended.
• Failsafe’s: Testing the system’s performance in the event of a total power loss.

Why Choose Meritas for Your AOV Strategy?

An AOV is a robust first line of defence. By combining mechanical ingenuity with the principles of risk management, Meritas ensures your building remains a safe environment for all inhabitants. Whether you are managing a high-rise residential block or a commercial office, we provide the expertise needed to keep your smoke ventilation systems compliant.