The part of the system nobody looks at until it fails
When people talk about smoke ventilation, they talk about the vent. The automatic opening vent (AOV) is the visible part, so it gets the attention: free area, size, finish, actuator type.
The control panel decides whether any of that works. It is the component that detects the fire signal, opens the right vents in the right order, keeps them powered when the mains goes down, and tells you when something is wrong. A well-chosen AOV on a poorly specified panel is still a poorly specified system.
This guide explains what an AOV control panel actually does and sets out the checks worth making before you put one on a specification or an order.
What an AOV control panel actually does
An AOV control panel is the power supply and decision-maker for a natural smoke ventilation system. It does four jobs.
It listens for a fire signal. The panel takes inputs from smoke detectors in the protected area, from a fire alarm interface, and from manual devices such as break glass call points. Each input is monitored, so a cut or shorted cable shows as a fault rather than silently disabling the system.
It decides what to open. On a confirmed signal, the panel drives the AOV actuators to open. In a typical residential stair core, that means the vent at the head of the stair and the vent on the fire floor. Larger panels can control separate zones, so a fire on one floor does not open every vent in the building.
It gives the fire service control. A firefighter's override switch, usually at fire service access level, lets the attending crew open or close vents manually regardless of what the automatic system has done. Ventilation buttons on each floor let building users open vents for everyday airing where the design allows it.
It keeps the system alive without mains power. The panel holds standby batteries that must open the vents and hold them in position during a mains failure. It charges those batteries, monitors their condition, and reports when they are failing.
Around those four jobs, the panel provides fault indication, status LEDs or displays, and volt-free contacts so the building's main fire alarm or a building management system can see what the smoke ventilation system is doing.
The standards that apply
The key product standard for the panel's power supply is BS EN 12101-10, which covers power supplies for smoke and heat control systems. Ask for evidence of compliance, not just a claim of it.
|
Document |
What it covers |
Why it matters for the panel |
|
BS EN 12101-10 |
Power supplies for smoke and heat control systems |
Sets requirements for the panel's power supply and standby operation |
|
BS EN 12101-2 |
Natural smoke and heat exhaust ventilators |
Covers the AOV the panel drives; the panel must match the actuator's electrical demand |
|
BS 7346-8 |
Code of practice for planning, design, installation, commissioning and maintenance of smoke control systems |
Sets out how the system should be designed, installed and kept working |
|
Approved Document B, Volume 1 |
Fire safety in dwellings, including common parts of blocks of flats |
Sets the functional requirement for smoke ventilation of common stairs and corridors |
|
BS 9991 / BS 9999 |
Fire safety design of residential / non-residential buildings |
Alternative design routes that may set different ventilation requirements |
Standards are revised regularly. Check the current edition of each document with BSI or the government's published Approved Documents before you rely on it, and confirm whether the project is being designed under an older edition.
In a higher-risk building (at least 18 m or 7 storeys with at least two residential units), the smoke control design forms part of the Building Safety Act approval process. Swapping a specified panel for an "equivalent" after approval may need to be managed as a change, so get the specification right first time.
What to check before you specify one
Most panel problems trace back to one of these eight questions going unasked.
1. Is it independently certified to BS EN 12101-10? Ask for the certificate and check it names the exact model, not a product family.
2. Can it carry the actuator load? Add up the current draw of every actuator the panel will drive, including when several open at once. Leave headroom for future changes.
3. Is the battery standby adequate? Confirm the standby period the panel is certified for and that the battery size quoted is the one that achieves it with your actuator load.
4. Does it have enough zones? One zone may suit a single stair. Multiple stairs, corridors or lobbies usually need separate zones so the right vents open for the fire floor.
5. How does it interface with the fire alarm? Check the inputs and outputs match what the fire alarm contractor is providing, and agree who owns the interface before installation.
6. Are the right field devices compatible? Detectors, break glass units, vent switches and the firefighter's override must be compatible with the panel. Mixing brands without confirmation is a common source of faults.
7. What cable does it need? Fire-resistant cable is required between the panel and its field devices. Confirm the cable category and maximum run lengths with the manufacturer.
8. Can it be maintained? Look for clear fault indication, an event log, and easy battery replacement. Ask whether spare parts and technical support are available in the UK.
Common specification mistakes
• Specifying the vent and leaving the panel to the installer. The panel then gets chosen on price, and its rating may not match the actuators.
• Undersizing for simultaneous opening. A panel that copes with one actuator at a time can fail when the stair vent and the floor vent open together.
• Treating the fire alarm interface as someone else's problem. If neither contractor owns it, it is often the last thing tested and the first thing to fail.
• Ignoring maintenance at design stage. Batteries have a finite life. A panel in a locked riser with no clear fault indication is easy to forget until it is needed.
• Accepting "equivalent" substitutions without evidence. An alternative panel needs the same certification, capacity and compatibility as the one it replaces.
Frequently asked questions
What is an AOV control panel?
An AOV control panel is the power supply and control unit for a natural smoke ventilation system. It receives signals from smoke detectors, the fire alarm and manual call points, opens the automatic opening vents, and keeps them working on battery power if the mains fails.
Does an AOV need a control panel?
Yes. An AOV actuator needs a monitored power supply and a control signal to open on a fire condition. The control panel provides both, along with standby power and fault monitoring.
Which standard applies to AOV control panels?
BS EN 12101-10 covers power supplies for smoke and heat control systems. BS 7346-8 gives guidance on design, installation, commissioning and maintenance. Always check you are working to the current edition.
How often should an AOV system be tested?
Smoke ventilation systems need regular testing and periodic servicing by a competent person. The frequency depends on the building type and the applicable guidance, so check BS 7346-8, the manufacturer's instructions and the building's fire risk assessment.
Can one control panel run several AOVs?
Yes, provided the panel is rated for the combined actuator load and has enough zones for the building's layout. Check the manufacturer's data before connecting additional vents.
Choosing the right panel
The right AOV control panel is the one that matches your actuators, your zones, your fire alarm interface and your maintenance regime, with certification to prove it.
Browse our range of AOV control panels, or speak to the Inbuild team with your vent schedule and actuator details. We can help you check load, zoning and compatibility before you commit to a specification.
This article is general guidance. Smoke ventilation design must be carried out and verified by a competent person against the current standards and the specific building.
