Car Park Ventilation Maintenance Explained

What Is This Guide For?

If you manage or own a building that has a smoke ventilation system, whether that’s an AOV (automatic opening vent) on a stairwell, extract fans in a smoke shaft, or a pressurisation system keeping corridors smoke-free, you are legally responsible for keeping it working.

Most building managers know this in theory but find the guidance confusing in practice. This page breaks it all down:

• What the law actually says (in plain English)
• What equipment you probably have and what it does
• Who should be checking it and how often
• What you need to write down
• How to find a company you can trust to service it

This guide is based on the official Smoke Control Association (SCA) Guidance on Maintenance of Smoke Control Equipment, written by industry experts including engineers from Vent Trade. It is aimed at building owners, managers, facilities teams, managing agents, and anyone else responsible for a building’s fire safety.

You don’t need to be an engineer to use this guide. You just need to understand what your responsibilities are and what questions to ask.

Why It Matters: The Basics

Smoke kills faster than fire

Most people who die in building fires do not die from burns, they die from smoke inhalation before the flames even reach them. Smoke spreads through a building in minutes, blocking escape routes and disorientating people trying to get out.

A smoke control system is designed to do one or more of the following:

• Keep escape routes clear, so residents and visitors can get out safely
• Give firefighters visibility, so they can find the fire and rescue people
• Stop smoke spreading, by creating pressure differences between areas or actively extracting smoke
• Buy time, even a few extra minutes can be the difference between life and death

Think of it like a car MOT

Your smoke control system is like a car. You can’t just install it and forget about it. Over time, parts wear out, batteries drain, actuators stiffen up, fans degrade. If you don’t service it, it might look fine, but when it’s actually needed in a fire, it won’t work.

Unlike a car, you can’t pull over if your smoke system fails. It needs to work first time, every time, in the worst possible conditions, at 3am, in a panic, with people’s lives depending on it.

Regular maintenance is not a box-ticking exercise. It is what keeps the system ready.

What happens if you don’t maintain it?

• Legal liability, you can be prosecuted under fire safety law, fined, and held personally responsible if someone is harmed
• Insurance problems, most building insurers require evidence of regular maintenance; without it, your policy may be void
• System failure in a fire, the most serious consequence; a system that hasn’t been tested or serviced may not operate when triggered
• Enforcement action, fire authorities can serve improvement or prohibition notices on your building

The Law: What You Must Do

There are three main pieces of legislation you need to know about. Here’s what they actually say in plain terms:

1. The Regulatory Reform (Fire Safety) Order 2005: “The Fire Safety Order”

Who it applies to: Almost every non-domestic building in England and Wales, workplaces, commercial premises, and the common areas of residential blocks (corridors, stairwells, lobbies, etc.).

What it says: The person responsible for the building (called the “Responsible Person” or “Duty Holder”) must ensure that fire safety equipment is properly maintained and kept in good working order.

In plain English: If your building has a smoke control system, you must have it serviced regularly. Full stop.

What it means for you: You need a documented maintenance programme, carried out by someone competent. You need to be able to show evidence of this if the fire service inspects your building.

2. The Building Safety Act 2022

Who it applies to: Buildings at least 18 metres in height or with at least 7 storeys (and containing at least 2 residential units), known as “Higher-Risk Buildings” (HRBs), typically high-rise residential blocks.

What it says: Every HRB must have a named Principal Accountable Person (PAP) who is legally responsible for building safety. This is usually the building owner or management company. The PAP has specific duties to manage and document all safety-critical systems, including smoke control.

In plain English: If you’re responsible for a tall residential building, you have extra legal duties, and they’re tied to you personally, not just the company.

What it means for you: You need a digital record of all fire safety assets (called the “Golden Thread of Information”). This includes your smoke control system, what’s installed, where it is, what it does, when it was last serviced, and any faults.

3. The Fire Safety (England) Regulations 2022

Who it applies to: High-rise residential buildings (the Fire Safety (England) Regulations 2022 sets duties at 11 m+; the Building Safety Act 2022 Higher-Risk Building regime applies at 18 m+ or 7-storey+, with at least 2 residential units).

What it says: Building managers must carry out monthly routine checks on fire safety equipment. Any fault that can’t be fixed within 24 hours must be reported to the local fire service electronically.

In plain English: Check your smoke system every month. If something’s broken and you can’t fix it fast, you must tell the fire brigade.

What it means for you: Monthly inspections are not optional for high-rise residential buildings. They are a legal requirement. And if your smoke system goes offline and you can’t get it fixed same day, you have 24 hours to notify the fire service before you’re in breach of the regulations.

Key Terms Explained

Before going further, here are the words that come up most often, explained without the jargon:

AOV (Automatic Opening Vent) A window, rooflight, or vent that opens automatically when smoke is detected, usually at the top of a stairwell. The idea is that hot smoke rises and escapes through the open vent, keeping the stairwell below clear. You’ve probably seen these, they’re often the louvred panels at the top of staircase windows that you can sometimes hear opening.

Smoke Shaft A dedicated vertical duct built into the building, running from the fire floor up through the roof. When a fire is detected, extract fans pull smoke out of corridors and into the shaft, then expel it at roof level. This keeps the corridor smoke-free so people can escape.

Control Panel / Status Panel The box (usually mounted in a lobby or plant room) that controls the whole smoke system. It shows whether everything is working normally or if there’s a fault. Think of it like the dashboard of a car, it tells you when something’s wrong.

Firefighter’s Switch (also called FOS, Firefighter Override Switch) A special manual switch, often in a glass-fronted box near the building entrance, that allows firefighters to take direct control of the smoke system when they arrive at an incident.

Actuator The motorised device that physically opens and closes vents, windows, and dampers. It receives a signal from the control panel and converts it into movement. If an actuator fails, the vent won’t open in a fire.

Damper A mechanical flap inside a duct or shaft that can open or close to control where smoke goes. In a fire, some dampers open to allow smoke extraction while others close to stop smoke spreading to non-fire floors.

UPS (Uninterruptible Power Supply) A battery backup system. If mains power fails during a fire, which is common, the UPS keeps the smoke control system running. Without it, the system could go dark at exactly the wrong moment.

ATS (Automatic Transfer Switch) A device that automatically switches the system’s power source from mains to a backup generator (or UPS) the moment it detects a mains failure. It’s the reason the system keeps working even during a power cut.

MMO (Maintenance Management Organisation) The company or team responsible for managing the maintenance of your system, essentially your maintenance contractor.

SMR01 The industry registration scheme for smoke control maintenance companies, administered by the Smoke Control Association (SCA) and independently audited via KIWA/UKAS. Engineers working on smoke control maintenance should either be trained by the smoke control manufacturer or be SMR01 registered. These are the two recognised competence paths. Look for this when hiring a Maintenance Engineer, more on this below.

Cause and Effect A document (or matrix) that maps out what happens when a specific trigger occurs, e.g. “if smoke detector on Floor 3 activates, vents on Floor 3 open, dampers on all other floors close, fans start.” It’s the instruction manual for how your system behaves in a fire, and it must be checked during maintenance to make sure the system still behaves as designed.

Essential Characteristics The technical performance requirements for each piece of equipment, for example, how wide a vent must open, or how much air a damper must allow through. These come from the original fire engineering design and must be verified during annual maintenance.

What Equipment Do You Have?

Before you can maintain a system, you need to know what you’ve got. This sounds obvious, but many buildings, especially older ones, have smoke control equipment that nobody has ever properly inventoried.

Starting from scratch: what to look for

Walk through your building and look for:

• Vents or rooflights at the top of stairwells, often louvred panels or motorised windows. These are almost certainly smoke vents (AOVs).
• A grey or black control panel, usually wall-mounted in a lobby, plant room, or near the entrance. This is the brain of the system.
• A firefighter’s switch, a red or yellow switch in a glass-fronted box, usually near the building’s main entrance. Essential for fire service access.
• Extract grilles in corridor ceilings, connected to ductwork running to a shaft or roof fan. Part of a mechanical extract system.
• Fans on the roof, large, weatherproof fans are almost always part of a smoke extraction or pressurisation system.
• Dampers inside ducts or at ceiling level, motorised flaps that control airflow. Often hidden behind access panels.
• Battery backup boxes, usually wall-mounted, may be labelled “UPS” or “battery pack.”

Check for labels and markings

Every piece of smoke control equipment should have a manufacturer’s label or data plate. This tells you the brand, model, and sometimes the installation date. Note these down, they’re useful when calling for maintenance or ordering spare parts.

What if you have no records?

This is more common than you’d think, especially in buildings that have changed hands, or where original installation paperwork was never passed on.

If you have no records, do not guess. Commission a survey by a competent smoke control specialist (see the section on hiring a Maintenance Engineer below). They will inspect every component, identify what you have, and produce an asset register, a list of every piece of equipment with its location, function, and condition. This is your starting point for everything that follows.

Your System: Car Park Ventilation

How it works: Car parks present a different challenge. They need ventilation during normal use to remove carbon monoxide (CO) from vehicle exhaust, and in a fire they need to remove smoke and heat to protect people and the structure.

Where you’ll find it: Any underground, covered, or enclosed car park.

What it looks like: Large fans (sometimes jet fans running along the ceiling), CO detectors, and a control system. Often runs continuously at low speed during normal operation.

Maintenance focus: Ensuring fans operate across their full range (low-speed normal operation through to full-speed fire mode), CO detector calibration, and fire mode interfaces.

Who Does What?

Smoke control maintenance involves four distinct roles. Each one has clearly defined duties, and each is essential, skip one and the system isn’t being properly maintained. Here’s exactly what each role looks like and what they need to do.

See The Inspection Schedule below for the full month-by-month playbook, and Hiring a Maintenance Engineer for what to look for when choosing your specialist.

Getting Started: New or Existing Building

If you’ve just taken over a building

The first thing you need is documentation. Before any maintenance can happen, the Maintenance Engineer needs to understand what the system was designed to do. This includes:

• System design drawings, showing where every component is located
• Cause and effect schedule, what triggers what (e.g. “detector on Floor 2 activates → vents on Floor 2 open, dampers on all other floors close”)
• Fire strategy document, the overall fire safety design for the building
• Previous maintenance records, what was serviced, when, and by whom
• Any non-conformance records, previous faults or issues that were noted

Get all of this from the previous owner, developer, or managing agent. If it doesn’t exist, which is more common than it should be, you’ll need a survey to establish what you have (see below).

Also get a current Fire Risk Assessment that covers the smoke control system. This tells you whether the system as installed is appropriate for the building as it is now used. Buildings change over time, partitions are moved, uses change, occupancy levels shift, and the fire risk assessment should confirm the system still meets the building’s needs.

If you have no documentation

Don’t panic, but do act quickly.

Commission a site survey from a specialist smoke control company. They will:

1. Walk the building and physically identify every smoke control component
2. Test each component to see if it operates
3. Produce an asset register listing everything they found
4. Produce a report noting any faults, gaps, or non-conformances
5. Advise on what documentation needs to be created or reconstructed

This survey is the foundation of everything else. Until you have it, you don’t really know what you’re maintaining, or whether the system is working at all.

The Inspection Schedule

The SCA guidance sets out minimum inspection intervals. Think of it like this:

The rest of this section breaks down exactly what happens at each interval and why.

Daily: “Is everything showing green?”

Who does it: Your Nominated Person (caretaker, concierge, site manager, etc.)

What they do: Walk to the smoke control panel (or check it remotely if you have a monitoring system) and confirm it shows a normal status, no fault lights, no alarm conditions.

How long it takes: Under 5 minutes.

What to do if something’s wrong:

1. Log it in the logbook immediately, date, time, what you saw
2. Try to resolve minor issues (e.g. resetting a panel after a spurious trigger)
3. If you can’t resolve it, call your maintenance company
4. If the fault affects the system’s ability to work in a fire, review your Fire Risk Assessment, you may need to implement temporary safety measures (e.g. increased patrols, posting a fire warden)
5. If you’re in a high-rise residential building and the fault can’t be fixed within 24 hours, you must notify the local fire service

Weekly: “Does the system actually work when triggered?”

Who does it: Competent Person

What they do: Physically trigger (actuate) the system and watch what happens. The goal is to confirm that every component does what it’s supposed to do when the signal arrives.

What to check each week:

• All status panels and Firefighter’s Switches show no faults
• Fans start and run, you should be able to hear them
• Dampers open on the triggered zone, you should hear them and possibly feel airflow
• Air inlets open as expected
• On reset, fans stop and all dampers and vents return to closed position
• No unusual sounds (grinding, rattling, humming where there shouldn’t be one)

Zone rotation. This is important: All zones in your building must be tested at least once every three months. To make this manageable, the SCA recommends rotating which zone you test each week:

• In a 1–5 storey building: test 1 zone per week
• In a 1–10 storey building: test 2 zones per week
• In a 1–15 storey building: test 3 zones per week
• In a 1–20 storey building: test 4 zones per week

Important note on linked systems: If your smoke control system is connected to other building systems, fire alarm, door holds, access control, always assess whether testing the smoke system might affect those. You may need to notify other system managers before testing, or temporarily isolate linked systems while tests are carried out.

After every weekly test: Write down what you tested, what you found, and any actions taken. See the record keeping section below.

Monthly: “Is the hardware in good shape?”

Who does it: Competent Person

What they do: All the weekly checks, plus a more thorough physical inspection of hardware, especially rooftop equipment and power supplies.

Rooftop and physical inspection:

• Check all rooftop fans, vents, and equipment for debris (leaves, bird nests, litter), wear, corrosion, signs of tampering, or damage
• Look for anything that shouldn’t be there, vegetation, pest activity, combustible materials near equipment

Door hold-opens:

• Test fire door hold-open devices by simulating mains power failure or triggering the fire alarm interface
• Confirm that doors release and close properly when power is cut
• This is a life safety function, a door that doesn’t close in a fire allows smoke to travel freely

Fan run time:

• Both duty fans (primary) and standby fans (backup) should each accumulate at least 20 minutes of run time per month
• This can be a single 20-minute test or accumulated across multiple runs during weekly tests
• The reason: fans that sit idle can seize or develop bearing problems. Regular running keeps them ready.

Power supply test:

• Cut the mains power supply to the system and confirm it switches over to backup (battery or generator) automatically
• Run the system on backup supply for at least 20 minutes
• At the end of the test, restore mains power and confirm everything returns correctly to mains and standby position

If you have a standby generator:

• Check fuel level, there should be enough for 72 hours of standby operation plus 3 hours at full load
• Top up fuel as required
• Check the generator control panel for fault indications

If you have a UPS (battery backup):

• Check the UPS control panel for fault indications

3-Monthly: “Have all zones been tested?”

Who does it: Competent Person

What they do: This is a checkpoint to make sure every zone in the building has been independently tested at least once in the past 3 months. If you’ve been rotating zones weekly as recommended, this should be easy to confirm from your logbook.

Every part of the system should have been exercised, including all fire detection inputs (detectors, call points) and any control interfaces (BMS, fire alarm panel).

If you find any zones that haven’t been tested, test them now and note why they were missed.

6-Monthly: “Is the system performing to its design specification?”

Who does it: Your Maintenance Engineer (specialist smoke control maintenance company)

This is the first level of inspection that goes beyond basic operational checks into technical verification. Your specialist will:

Review your logbook:

• Were weekly and monthly checks being done?
• Were any faults recorded and resolved?
• Any outstanding issues?

Cause and effect verification:

• Check that the system still behaves exactly as the original fire engineering design required, that the right things open and close in response to the right triggers
• This is important because systems can drift over time, especially if there have been modifications to the building or the system

Power supply detailed checks:

• Verify the ATS (Automatic Transfer Switch) has a current service report (within the last 12 months)
• Confirm the ATS hasn’t been changed from its original configuration (e.g. a dual supply changed to single)
• Check all low-voltage electrical circuits, no earth leakage devices should be present (these can inadvertently disconnect the system)
• Check the controller’s supply is a “secure” unswitched type, if it’s on a switched fused spur (like a plug socket that can be turned off), that needs to be corrected

Battery testing:

• Panel batteries must be no more than 3 years old from manufacture date
• Batteries are tested using an intelligent battery tester. This is different from just measuring voltage; a failing battery can hold voltage but collapse under load
• Any battery that fails the test is replaced
• Undated batteries are replaced and labelled with the installation date
• PLC (Programmable Logic Controller) batteries, if your system has one, should be replaced every 2 years

For mechanical systems, flow rate measurements:

• The Maintenance Engineer physically measures the actual airflow through smoke dampers and doors using an anemometer
• At minimum 9 measurement points are taken (top, middle, and bottom of the shaft at different positions)
• These readings are compared to the design flow rates from the original fire engineering specification
• Temperature and barometric pressure are recorded alongside, to allow corrections for weather conditions
• This is how you know whether the fans and dampers are actually moving the right amount of air, not just that they’re turning on

After the 6-monthly inspection: Your Maintenance Engineer should issue a Maintenance Certificate confirming whether the system has:

• Passed, everything working as designed
• Passed with advisories, working but with minor issues that need monitoring or scheduling
• Failed, something critical isn’t working; action required

Annual: “Does the system still match the original design?”

Who does it: Your Maintenance Engineer. They must either be trained by the smoke control manufacturer or be SMR01 registered (the industry competence standard for maintenance)

The annual inspection is the most thorough, effectively a full recommissioning of the system against the original fire strategy. Your engineer will carry out everything from the 6-monthly check plus:

Full commissioning-level check:

• Every component tested against the original cause and effect matrix
• System performance compared to the original fire engineering design criteria
• Any non-conformances recorded and reported

Critical physical inspections:

• Shaft doors and dampers inspected for correct operation, intumescent seals (the fire-expanding strips around the edges) must be present and undamaged
• All vents checked to confirm they meet the required free area of ventilation (from Approved Document B or the original fire engineering design)
• Window vents confirmed to be higher than 1100mm from floor level (for fall safety reasons), if not, fall protection must be in place
• Rooftop vents confirmed to open fully and not be obstructed
• Smoke shafts checked, nothing should have been installed inside a smoke shaft that isn’t part of the smoke control system (it’s surprisingly common for other trades to run services through smoke shafts because they’re convenient vertical routes)

Electrical checks:

• Cable installation verified against Approved Document B, BS 8519, BS 7671, and SCA guidance
• Correct cable types for fire safety circuits

Duct and shaft cleaning:

• All smoke control ducts and shafts must be cleaned at least annually. This is required by BS 9991:2024
• Cleaning certificates must be provided to your smoke control engineer before they can validate the system pass
• Unclean ducts accumulate grease, dust, and debris that can restrict airflow or become a fire risk themselves

Detector replacement:

• If your smoke control system has integrated smoke detectors (detectors that are part of the smoke system rather than the separate fire alarm), detectors over 10 years old must be checked and replaced

Joint inspection:

• An annual joint inspection with your other specialist maintenance providers (fire alarm, sprinkler, BMS) is recommended, to verify that the interfaces between systems all still work as intended
• For example: does triggering a smoke detector on the fire alarm actually cause the correct smoke control zones to activate?

After the annual inspection: Your Maintenance Engineer issues a full Maintenance Certificate. This is a formal document confirming the functional integrity of the system. Keep it, you’ll need it for building control, insurance, and fire authority inspections.

What to Write Down

Good record keeping is not just about compliance, it’s how you actually manage the system over time. Without records, you don’t know what’s been tested, what’s been fixed, or what’s overdue.

The system logbook

Every smoke control system should have a logbook. This can be a physical folder kept near the control panel, or a digital record, whichever works for your building.

For every check or test, record:

• Date and time
• Who carried out the check (name and role)
• What was tested (which zone, which component)
• What the result was, did it work? Any issues?
• Any faults found and what action was taken
• Whether any outstanding faults have been referred to the MMO (your maintenance company)

Keep it honest. A logbook that shows nothing was ever wrong is suspicious, and a logbook that shows faults were found and dealt with is actually reassuring evidence that the system is being properly managed.

Maintenance certificates

After every 6-monthly and annual inspection, your maintenance company should provide a Maintenance Certificate. This is a formal document that states:

• What was inspected
• What the outcome was (Pass / Pass with advisories / Fail)
• Any actions required and by when
• The engineer’s name and certification details

File these certificates carefully. They are your evidence of compliance if the fire service or building control ever ask.

The 24-hour reporting rule

Under the Fire Safety (England) Regulations 2022 (for high-rise residential buildings), if a fault is identified with fire safety equipment that cannot be rectified within 24 hours, you must report this to the local fire and rescue service electronically.

This means: If your smoke system has a fault on a Friday afternoon and your maintenance company can’t attend until Monday, you need to notify the fire service. They won’t necessarily come out, but you need to tell them, and you may need to implement interim safety measures in the meantime (e.g. more frequent patrols, temporary fire watches, or disabling hazardous activities in the building).

What “Golden Thread” means for you

If you manage a Higher-Risk Building (at least 18 m in height or with at least 7 storeys, containing at least 2 residential units), the Building Safety Act 2022 requires you to maintain a “Golden Thread of Information”, a live, up-to-date digital record of safety-critical information about your building, including your smoke control system. This means your asset register, maintenance records, and certificates should be stored digitally and kept current at all times.

Hiring a Maintenance Engineer: What to Look For

This is one of the most important decisions you’ll make. A poor maintenance company might tick the boxes on paper but miss the things that actually matter. Here’s how to hire the right people.

The non-negotiable: manufacturer training or SMR01 registration

The competence standard for smoke control maintenance is clear: engineers must either be trained directly by the smoke control manufacturer or be SMR01 registered. Both routes demonstrate proven competence on smoke control systems.

SMR01 is the Smoke Control Association’s registration scheme for smoke control maintenance organisations. It is:

• Independent, administered by the SCA and audited by KIWA/UKAS accredited bodies, not self-certified by the industry
• Competency-based, every company’s engineers are assessed every 5 years on their actual knowledge, skills, and processes, not just paperwork
• The industry standard, required by the SCA’s official Maintenance Guidance and recognised across building control and fire safety

Manufacturer training is the equivalent route: engineers trained directly by the manufacturer of the equipment installed in your building. This route is only valid for the specific equipment the engineer has been trained on. It does not transfer to other manufacturers’ kit.

Ask any prospective maintenance company: “Are your engineers trained by the smoke control manufacturer, or are you SMR01 registered?” If they can’t answer yes to at least one, look elsewhere.

A list of SMR01 registered organisations is available from the Smoke Control Association website.

Questions to ask when getting quotes

1. Are your engineers trained by the smoke control manufacturer, or are you SMR01 registered? (Non-negotiable)
2. Do you have experience with my type of system? (Mechanical, natural, pressurisation, car park)
3. What will the 6-monthly inspection include? (Should include flow rate measurements, battery testing, cause-and-effect verification)
4. What will your annual inspection include? (Should be a full commissioning-level check against the fire strategy)
5. Can you provide a sample Maintenance Certificate? (Should clearly state Pass/Pass with advisories/Fail and include engineer credentials)
6. Do you carry common spare parts? (A company that has to order every part will leave your system offline longer)
7. What’s your response time for emergency callouts? (What happens if your system goes down at 11pm on a Friday?)
8. Do you work with my fire alarm company? (Coordination for annual joint inspection)

Red flags to watch for

• A company that can’t explain what a cause-and-effect schedule is
• A company that doesn’t ask for your system documentation before attending
• A very cheap quote with no detail on what the inspection will cover
• A company that’s never heard of SMR01 or can’t name the manufacturers they’ve been trained by
• A maintenance certificate that just says “system inspected, all okay” with no detail

What your Maintenance Engineer needs from you

When you first engage a maintenance company, provide them with:

• All system documentation you have (drawings, cause-and-effect, fire strategy)
• Previous maintenance records and certificates
• Details of any known faults or modifications
• Access to all areas (including roof, plant rooms, and all floors)
• Contact details for other system maintainers (fire alarm, sprinkler, etc.)

The better the information you give them, the better the maintenance they can provide.

Vent Trade

Vent Trade’s maintenance engineers are trained directly by the smoke control manufacturer and SMR01 registered, meeting both recognised competence paths. We have been commissioning and maintaining smoke control systems since 1988, are members of the Smoke Control Association, and part of the working group that helped produce the SCA guidance this page is based on.

Our engineers carry out maintenance visits across the UK, providing functional testing, cause-and-effect verification, flow rate measurements, battery testing, system logbook review, and full maintenance certification.

Contact us for a maintenance quote or call us on 01202 725485.