Brett Martin AOV Smoke Vent Central Actuator 365mm Kerb

Brett Martin Mardome Trade AOV smoke vent – central actuator, 365mm PVC kerb

An Automatic Opening Vent (AOV) smoke vent from Brett Martin’s Mardome Trade range, supplied with a 365mm sloping PVC kerb that fixes straight onto the roof deck (no separate upstand needed) and glazed with a polycarbonate dome. The actuator is mounted centrally, giving a symmetrical lift and the simplest choice where roof access through the vent isn’t required. Designed to open automatically when the fire detection system is triggered, it clears smoke and heat from corridors, lobbies and stairwells, opening to 140° in under 60 seconds. Tested and certified to BS EN 12101-2 and compliant with Approved Document B.

At a glance

• Actuator: Central actuator
• Kerb: 365mm PVC kerb – fits directly onto the flat roof deck
• Glazing: Polycarbonate dome, clear or opal, double or triple skin
• Wind deflectors: Optional – increase the aerodynamic free area (see table below)
• Opening: 140° in less than 60 seconds; hinged on the long side for rectangular sizes
• Roof pitch: Suitable for flat roofs up to 15° – hinge side must face up the slope
• Certification: BS EN 12101-2, CE marked, Approved Document B
• Guarantee: 10 years

365mm PVC kerb – how to measure

The 365mm sloping PVC kerb is thermally broken and fixes directly onto the roof deck, so no separate upstand is required. The smoke vent size is the external dimension measured at the base of the kerb where it meets the roof. The daylight opening is 150mm smaller than the smoke vent size in each direction – a 1050 x 1050mm vent gives a 900 x 900mm daylight opening.

Offset or central actuator?

This vent has a central actuator: the arm is mounted in the middle of the opening, giving an even lift across the lid. It’s the standard choice for pure smoke ventilation where nobody needs to climb through the vent. If you need the vent to double as roof access, see our offset actuator version.

Wind deflectors

Wind deflectors manipulate the air flow over and around the AOV and increase its aerodynamic free area (Aa) in every size. A smaller AOV with wind deflectors can match or out-perform a larger one without, which is particularly useful where a stairwell vent has to achieve an Aa of at least 0.70m² as required by EN 12101-2. Select the wind deflector option above and compare the two sets of figures in the table below.

Aerodynamic free area – 365mm PVC kerb

Figures from Brett Martin’s Mardome Trade technical data (TB285), tested to EN 12101-2 Annex B. Sizes available to order are listed in the size selector above. Rectangular sizes are hinged on the long side.

* Below 0.70m² – not suitable for stairwell use, where EN 12101-2 requires an aerodynamic free area (Aa) of more than 0.70m². Note this is the aerodynamic free area, not the geometric “free vent area” that is often quoted. Free area (final column) is the geometric free area in accordance with Approved Document B Volume 2, Appendix C.

Understanding free area

Free area is the size of the vent at its smallest point, measured at right angles to the air flow, minus the area of any obstructions such as motors, ladders or grilles. Coefficient of discharge (Cv) is a third-party tested value that quantifies how efficiently air actually passes through the vent. Aerodynamic free area (Aa) is the vent size multiplied by the Cv – the true performance figure for the vent. It is the value used in EN 12101-2, BSI and UKCA certification and quoted on NBS specifications, so it’s the number to check against your fire strategy.

Certification and performance

• Tested and certified to BS EN 12101-2 – opens to 140° in less than 60 seconds
• Fire rating: Class B-s1, d0 to BS EN 13501-1 and deemed B_ROOF(t4) to BS EN 13501-5
• Non-fragility: Class B to ACR[M]001; dome impact resistance 1200 joules to EN 1873
• Part L compliant polycarbonate glazing with good thermal performance and resistance to condensation
• Wind deflectors included where required by the regulations for the size ordered
• 72-hour battery back-up in the event of a power cut (via control panel)
• CE marked; 10-year guarantee; designed to last in excess of 20 years under normal conditions

Thermal and acoustic data

Construction

• Suitable for residential and commercial buildings
• Thermally broken PVC kerb, weatherproofed to the full height of the upstand
• Extremely secure – concealed individual fixings within security caps
• Hinged on the long side (rectangular sizes)

Operation and control

The actuator should be connected to an EN 12101-10 compliant control panel. We recommend the Brett Martin AOV control panel, which is designed for this actuator and provides battery back-up and line monitoring. The panel can be triggered by dedicated smoke detectors, manual override / fire brigade switches, or through integration with an existing fire alarm or building management system. The vent can be installed with other EN 12101-10 control systems without affecting the guarantee, though we can’t offer technical support on third-party controls.

Related items: Control panel, Smoke detector, Fire switch, Fire brigade priority switch.