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AOV Design
AOV surveys, system design and cause and effect for new and replacement smoke control systems across London and the South East.
From reviewing existing vents and controls to agreeing the cause and effect with you or your fire engineer, with safe access for future maintenance considered in the design.
Fire Systems Ltd surveys and designs new and replacement AOV and smoke control systems for housing associations, local authorities and commercial clients across London and the South East. Because we also look after the fire alarms that trigger them, we consider the whole sequence from the detector in the lobby to the vent at the top of the stair.
Design. We design the replacement or new system to BS 7346-8, with safe access for future maintenance, and agree the cause and effect with you or your fire engineer.
For delivery of the agreed system, see AOV Installation
Smoke Control Competence and Certification
Fire Systems Ltd is certified under the IFC Certification SDI 19 scheme for the installation, commissioning and maintenance of smoke control systems (certificate IFCC 3453), audited by a UKAS-accredited certification body. We are members of the Smoke Control Association and NICEIC registered for the electrical work involved.
Our smoke control engineers work to BS 7346-8 and hold manufacturer training on the systems we install. On housing projects we act as Principal Designer and Principal Contractor under CDM 2015.
AOV Design and Equipment Selection
BS 7346-8. The code of practice for planning, design, installation, commissioning and maintenance of smoke control systems.
BS EN 12101. The product standards for smoke control equipment, including natural smoke and heat exhaust ventilators (Part 2) and power supplies (Part 10).
BS 8519. The code of practice for fire-resistant cables that must keep working during a fire, which we follow when selecting smoke control cabling.
Approved Document B. Sets out when new and altered buildings need smoke ventilation to common stairs, corridors and lobbies, and how large the vents must be.
BS 9991 and BS 9999. The codes of practice for fire safety design of residential and non-residential buildings, including smoke ventilation.
CDM 2015. AOV installation is construction work, often at height and in occupied buildings, and needs proper planning and competent people in the Principal Designer and Principal Contractor roles.
What an AOV system includes
Control panels and power supplies. Networked AOV panels with standby batteries, so the vents still open if the mains supply fails.
Vents and actuators. Windows, roof vents, shaft vents and louvres, opened by chain or linear actuators sized for the vent.
Detection. Smoke detectors in the lobbies and corridors that trigger the right vent on the right floor.
Firefighter controls. Override switches that let the fire service open or close the vents manually.
Fire-resistant cabling. Cabling that keeps the system working during a fire.
Interfaces. Links to the fire alarm, door holders and any smoke shaft, set out in the cause and effect.
When to Review an AOV System
A survey helps establish whether an existing system needs repair, replacement or changes to its cause and effect.
Repeated faults: Panels that keep going into fault, open circuits and missing cabling, often down to the age of the installation.
Fire risk assessment actions: The assessor has found vents that do not open, interlocks that do not meet the standard, or a system that does not match the fire strategy.
Obsolete equipment: Panels and actuators that are no longer made, so repairs are slow, costly or impossible.
Higher-risk buildings: Buildings of 18m and over need smoke control that is checked monthly and fully documented for the golden thread.
Refurbishment: Window replacements, new doors or changes to the stair core that affect the smoke ventilation.
Not sure whether to repair or replace? We survey the system, test it against the cause and effect and give you a clear, costed recommendation for both options.
From Survey to AOV Design
Survey. We inspect the existing vents, actuators, panels, detection and cabling and test the system against the cause and effect.
Design. We design the replacement or new system to BS 7346-8, with safe access for future maintenance, and agree the cause and effect with you or your fire engineer.
We consider safe access for future maintenance and agree the cause and effect with you or your fire engineer.
Continue to AOV Installation
For ongoing checks and repairs, see AOV Maintenance
Defining the Cause and Effect
The cause and effect sets out which detector opens which vent, which doors release and what the fire alarm does. Where it is missing or no longer matches the building, we produce one.
The system includes the detector, panel, vent, door holders, fire alarm interface and firefighter override. These connections are tested together at commissioning.
Safe access for future maintenance is considered in the design, alongside the equipment and the cause and effect.
In Practice: Survey and Design for a Six-Storey Block
A London housing association asked us to look at an AOV system in a six-storey residential block that kept going into fault. Our design engineer surveyed the system and found open circuits and missing cabling, most likely down to the age of the installation. The building’s smoke ventilation relied on six magnetically held doors, a vent at the head of the stairs and a vent at the top of the smoke shaft, and the interlocking between them did not meet the required standard.
Design. We recommended a full replacement and produced a design and detailed quotation. The new system comprised eight mains supplies, eight networked AOV control panels across six floors, eight chain actuators, seven smoke detectors and eight firefighter override switches. New cabling was selected to BS 8519, and the layout allowed for safe access for future maintenance.
Read about installation, commissioning and handover on AOV Installation
AOV Design Questions
What is a cause and effect?
A document that sets out exactly what happens when each device operates: which detector opens which vent, which doors release and what the fire alarm does. We commission every system against it and produce one where it is missing.
What documents will we receive?
Design, installation and commissioning certificates, O&M manuals, logbook documentation and a building plan showing every device, cable route and network schematic, ready for your golden thread records.
