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X-AOV

Multipurpose automatic opening vent that combines natural smoke and heat exhaust, comfort ventilation, and safe roof access in one versatile unit.

Open roof window mechanism with metal frame for ventilation and light.

Key benefits

X-AOV offers 3-in-1 functionality, combining smoke ventilation, natural ventilation, and roof access.
It provides design flexibility, with lid options in glass, polycarbonate, or insulated aluminium.
It delivers fast response performance, opening to 140° in under 60 seconds.
It incorporates thermally broken insulated kerbs, reducing the risk of condensation in heated spaces.
It ensures tested safety and durability, with compliance to EN 12101-2 and proven performance against wind, snow, heat, and weather exposure.

Product details

The X-AOV is a fully tested automatic opening vent rooflight that serves as a smoke and heat exhaust ventilator (NSHEV), a comfort ventilator, and a safe roof access hatch. Available in multiple lid options and sizes, the X-AOV is designed for reliability, flexibility, and compliance with industry standards.

Suitable for:

  • flat and low-pitch roofs up to 15°, providing effective smoke control and ventilation
  • buildings requiring NSHEV compliance, with units designed, tested, and CE/UKCA-marked according to BS EN 12101-2
  • projects needing roof access, with lids opening up to 140° in under 60 seconds
  • heated or unheated spaces, with insulated or non-insulated kerb options available
Functions and sizes
Glazing (performance/options)
Additional solutions
Product features
Safety systems
Comfort ventilation and SHEV

Performance

  • Thermal insulation (Ud):
    • Glass lid: 1.25 W/m²K
    • Polycarbonate lid: 1.54 W/m²K
    • Aluminium lid: 1.66 W/m²K
  • Aerodynamic free area (Cv): 0.40 (EN 12101-2).
  • Weather resistance: tested with weather cowl for use in adverse conditions.
  • Reliability (Re): 1000 cycles.
  • Snow load (SL): 600 Pa.
  • Wind load (WL): 1500 Pa.
  • Resistance to heat (B): 300 °C.
Open VELUX roof window on a green rooftop with city view.
X-AOV combines smoke ventilation, everyday comfort airflow and roof access in one intelligent, space-saving rooflight solution.
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Frequently asked questions

What is an Automatic Opening Vent (AOV)?

An Automatic Opening Vent (AOV) is a smoke ventilation system designed to open automatically in the event of a fire. Its primary purpose is to remove smoke, heat, and harmful gases from a building, helping to maintain safer conditions inside.

How do AOV rooflights protect building occupants during a fire?

AOVs extract smoke and hot gases from the building, which helps:

  • Keep escape routes such as corridors and stairwells clearer
  • Improve visibility for occupants evacuating
  • Reduce exposure to toxic fumes and extreme heat

This supports safer and more efficient evacuation.

When do AOV rooflights activate?

AOVs are typically triggered automatically by the building’s fire detection system, such as smoke or heat detectors. In some cases, they can also be activated manually via emergency override switches.

Where are AOV rooflights commonly installed?

AOVs are often installed in:

  • Stairwells
  • Corridors
  • Lobbies
  • Atriums and large open spaces

These are areas where smoke can quickly accumulate and hinder safe evacuation.

Can the AOV Rooflight also provide roof access and comfort ventilation?

Yes. The AOV can be specified to allow manual or automated opening for roof inspection, maintenance or everyday fresh-air ventilation.

What electrical controls are needed?

The AOV operates via a 24 V DC actuator system, compatible with control panels, smoke detectors and BMS integration. Battery backup options ensure operation during mains power loss.