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Automatic Opening Vents
IFC SDI 19 certified AOV and smoke control installation, testing and maintenance to BS 7346-8 for housing providers and commercial buildings in London.
From replacing failing systems to monthly checks and 24/7 repairs, Fire Systems Ltd looks after AOVs and smoke control for their whole life under IFC SDI 19 certification, tested together with the fire alarm.
An automatic opening vent (AOV) is a window, roof hatch or shaft vent that opens by itself when smoke is detected. In most blocks of flats it sits at the head of the stair or on each floor's common corridor or lobby, and it is there for two reasons: to let smoke escape so residents can still use the stairs, and to give firefighters a clearer, cooler route to the fire.
Smoke, not flames, is what stops most people escaping. A single flat door left open can fill a corridor with smoke in minutes. If the vent at the top of the stair fails to open, or opens on the wrong floor, the one escape route in the building can become impassable.
Fire Systems Ltd has worked in fire protection since 1992. Our own directly employed engineers install, commission and maintain AOVs and smoke control systems for housing associations, local authorities and commercial clients across London and the South East, usually alongside the fire alarm that triggers them. Because we look after both systems, we test them together and prove the whole sequence works, from the detector in the lobby to the vent at the top of the building.
IFC Certified for Smoke Control (SDI 19)
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). The scheme is run by a UKAS-accredited certification body, which audits our procedures and inspects our work. We are also members of the Smoke Control Association.
Our smoke control engineers work to BS 7346-8 and hold manufacturer training on the systems we maintain. Our Technical Manager, Dax Patel, verifies each engineer's competence before they are authorised, and every qualification and expiry date is held in our Mango QMS, which stops anyone being allocated to work they are not certified for.
SDI 19 sits alongside our other certifications: BAFE SP203-1 (fire alarms), SP203-4 (emergency lighting), SP207 (evacuation alert systems), SP101 (extinguishers), DS301 (domestic detection), NICEIC, and ISO 9001, 14001 and 45001.
The Regulations and Standards Behind Smoke Control
Smoke control is covered by fire safety law, building regulations and a set of British and European Standards. These are the ones that shape our AOV work:
Regulatory Reform (Fire Safety) Order 2005. Article 17 requires the responsible person to keep fire safety facilities, including smoke ventilation, in efficient working order and good repair.
Fire Safety (England) Regulations 2022. Since 23 January 2023, residential buildings of 18m or seven storeys and above must have smoke control systems checked every month. Any fault that cannot be fixed within 24 hours must be reported to the local fire and rescue service.
Building Safety Act 2022. In higher-risk buildings, smoke control records form part of the golden thread of building information, and the Accountable Person must be able to show the system is managed.
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 7346-8. The code of practice for planning, design, installation, commissioning and maintenance of smoke control systems. It is the standard we service to.
BS EN 12101. The product standards for smoke and heat control equipment, including natural smoke and heat exhaust ventilators (Part 2) and power supplies (Part 10).
BS 9991 and BS 9999. The codes of practice for fire safety design of residential and non-residential buildings, including smoke ventilation.
We also follow the cause and effect for each building: the document that says exactly which detector opens which vent, and what the fire alarm does at the same time. Where there isn't one, or it no longer matches the building, we produce one.
Our AOV services
Installation & upgrades. New systems, replacements and upgrades, commissioned against the cause and effect
Servicing & repairs. Monthly checks, annual services and 24/7 repairs to BS 7346-8
Why Some Buildings Depend on Smoke Control More Than Others
Every building with a common escape route benefits from keeping it clear of smoke, but in some buildings the AOV is doing a far more critical job.
General needs blocks of flats: Most purpose-built blocks are designed for residents to stay in their flat unless the fire is in their home. That only works if the common corridors and stairs stay usable, so the AOV is what makes the stay-put strategy safe. In a single-stair block there is no second way out.
Higher-risk buildings of 18m and over: Firefighters need a clear stair to reach the fire floor. Smoke control in these buildings must now be checked monthly under the Fire Safety (England) Regulations 2022, and faults reported to the fire service.
Sheltered and supported housing: Residents may move slowly, need help from staff, or wait in their flat for the fire service. Corridors and stairs need to stay clear of smoke for longer, so a vent that fails to open has a bigger impact.
Hotels and student accommodation: People are asleep, in an unfamiliar building, and may not know where the stairs are. Smoke-free corridors give them time to find the exit.
Not sure whether your system does what your fire strategy expects? We survey the building, test the system against the cause and effect, and tell you plainly what works, what doesn't and what it will cost to put right.
AOVs for the Whole Life of Your Building
Most clients come to us for one of two reasons. Each has its own page with the detail:
A system needs installing, replacing or upgrading. AOV installation and upgrades
An existing system needs servicing or repairing. AOV servicing and repairs
Because the same certified team installs and maintains both the AOVs and the fire alarm that triggers them, every building's smoke control records stay together.
Experience across thousands of homes
Installation. A faulty, non-compliant smoke vent system replaced across six storeys in four days, with eight networked panels, eight actuators and eight firefighter switches, while residents stayed at home.
Maintenance. Monthly AOV inspections across 1,500 homes since April 2022, at 96% compliance, and AOV maintenance across around 3,500 homes, including higher-risk buildings, for another major housing provider.
Our engineers carry contract-specific van stock, so replacement actuators, switches and panels are fitted quickly, and certificates are issued electronically within 48 hours.
“One certified team for the AOVs and the fire alarm that triggers them, so the whole sequence is proven at every visit.”
Fire Systems Ltd is IFC SDI 19 certified for smoke control and BAFE SP203-1 certified for fire alarms.
Choosing an AOV Contractor: What to Check
Smoke control certification. Ask for IFC SDI 19 or equivalent third-party certification covering installation, commissioning and maintenance.
Fire alarm capability. AOVs are triggered by detection. A contractor who can also test the fire alarm can prove the whole sequence.
Cause and effect. Ask how they test against it, and whether they will produce one if it is missing.
Monthly checks for higher-risk buildings. Make sure the contractor can deliver and record the monthly checks the law requires in buildings of 18m and over.
Spare parts. Ask what they carry on their vans. Actuators and panels that have to be ordered mean vents stay in fault for longer.
Records. Certificates within days, defects reported with quotations and records that support the golden thread.
AOV Questions We Are Often Asked
Which AOV service do I need?
If your system keeps going into fault, has failed or needs replacing, see AOV installation and upgrades. If it is working and needs regular checks, servicing or repairs, see AOV servicing and repairs.
What does an AOV actually do?
When smoke is detected in a common corridor or stair, the AOV opens automatically to let the smoke out. This keeps the escape route usable for residents and gives firefighters a clearer route to the fire.
What is a firefighter override switch?
A key switch, usually at the ground floor entrance or on each level, that lets the fire service open or close the vents manually. It should be tested at every service.
Who is responsible for AOVs in a block of flats?
The responsible person under the Fire Safety Order, usually the landlord, freeholder or managing agent. In buildings of 18m and over, the Fire Safety (England) Regulations 2022 also require monthly checks and reporting of faults to the fire service.
Do you cover my area?
We work across London and up to around 25 miles outside it, from our base in Kingston upon Thames.
