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Automatic Opening Vents (AOV)

Automatic Opening Vents - AOV

Stardome Automatic Opening Vent

Designed to reduce smoke build-up, helping to provide a safer escape route for occupants and access for fire-fighting personnel. Working in partnership with leading specialists in control systems we provide a complete package of smoke ventilation options.

Helping you comply with Building Regulations

In England and Wales Part B of the Building Regulations covers fire and the Approved Document (AD B) Volume 2 provides guidance applicable to flats and non-dwellings.

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Stardome Automatic Opening Vent Rooflight (AOV)

The following national, regulatory guidelines have similar requirements: Section 2 of the Scottish Building Standards Agency Technical Handbooks 2007; Technical Booklet E of the Building Regulations (Northern Ireland); Technical Guidance Document B of the Government of Ireland Building Regulations 2006. AD B identifies some situations where AOVs providing natural ventilation are appropriate, including:
• Small single-stair blocks of flats
• Common escape routes in larger blocks of flats
• Basement areas
• Enclosed car parks
• Vertical smoke shafts as part of a smoke control design
Stardome Smoke Vent Close Up
In several cases AD B specifies the minimum required level of ventilation – generally either 1m2 or 1.5m2.

Thermadome Automatic Opening Vents / AOVs

Therma-vent Automatic Opening Vents (AOVs)

Therma-Vent Automatic Opening Vents (AOVs)
Therma-Vent smoke vents/AOVs are designed to reduce smoke build-up, thus providing a safer escape route for occupants and access for fire-fighting personnel. The system can also be utilised to provide natural ventilation.

Therma-vent Smoke vent Rooflight

A typical smoke ventilation system includes Therma-Vent smoke ventilator (AOVs) located at the highest point of an escape route staircase or at the top of a smoke shaft. Smoke detectors and manual control points are normally located on each floor. The system can be controlled by a Therma-Vent control panel.

In the event of a fire the smoke detectors on the relevant floor instruct the control panel to operate the Therma-Vent AOV creating an upward air flow, venting smoke and toxic gases. The system can be designed to automatically open on receipt of a fire signal, or be controlled by the Therma-Vent control panel on instruction of the fire services. Alternatively, the Therma-Vent AOVs can be linked to the Building Management System (BMS) for complete monitoring.

Building Regulations
The design of natural smoke ventilation systems for buildings is governed by Building Regulation Approved Document B. For residential buildings the basic requirements of Approved Document B state that a smoke ventilation system must be provided if the travel distance between an apartment door and the nearest escape stair is greater than 7.5 metres.

National Domelight Company Therma-Vents can satisfy Building Regulations, including Approved Document B and European Standards EN 12101-2 as part of a designed smoke ventilation system. The responsibility for determining that any building component complies with the relevant regulation rests solely with the customer or specifier.

Therma-vent control system
Therma-vent Control Panels supplied as part of a smoke ventilation system can operate up to four AOV rooflights. Accessories include the Therma-vent Optical Smoke Detector with mounting socket and red LED status indication, the Therma-vent Break Glass and Therma-vent Fireman's Key Switch.

The Therma-vent Control Panel is supplied ready to install with batteries fitted and all internal wiring complete and tested. This enables quick installation times with virtually no scope for wiring errors. It is supplied complete with open, close and reset buttons and LED status indicators behind a break glass panel. The LEDs provide instant status indication, showing any system or wiring faults, system activation and vent position. When used with an AOV the priority control will respond to signals from smoke detectors and manual control points and Fireman’s Switch in order of importance. For natural ventilation the control panel is supplied with a key to remove the break glass to enable operation of the open / close / reset buttons to operate the AOV.
The Therma-vent Control Panel can be installed to operate as a simple centralised ‘stand alone’ system or a larger decentralised or ‘networked’ system with additional Therma-vent Control Panels.

A ‘stand alone’ Therma-vent Control Panel may be installed to operate on the instruction of the fire service. Alternatively it may be installed to operate on receipt of a fire signal from either a smoke detector or manual control point mounted within the fire zone.
This drawing shows a centralised 'stand alone' Therma-vent Smoke Ventilation system installed in an escape route staircase. Manual control points activate the OV.

Stand Alone Smoke Vent System
A networked Therma-vent system involves control panels distributed around the building, each controlling a zone with up to four AOVs. This enables cabling distances to be reduced.
Networking requires the installation of a Therma-vent Control Panel within each fire zone. These can be linked to the central control zone utilising Fireman’s Switch control points.
Individual zones activated by smoke detectors or manual control points can be overridden by the centrally mounted Fireman’s Switches.
Alternatively the Therma-vent Control Panel can be installed as part of a larger system receiving signals from a BMS via its ‘no voltage’ monitoring capacity.
Networked Therma-vent Smoke Ventilation system installed in living accommodation, escape route staircase and smoke shaft. Smoke detectors and manual control points activate the AOV. Fireman's switches enable central control.

Networked Smoke Vent System
Therma-vent Accessories:
• Therma-Vent Optical Smoke Detector
• Therma-Vent Break Glass
• Therma-Vent Fireman’s Key Switch

When specified, the Therma-Vent control panel is supplied ready to install with batteries fitted and all internal wiring complete and tested. It can be installed to operate as a simple centralised ‘standalone’ system, or a larger de-centralised or ‘networked’ system with additional Therma-Vent control panels.

Therma-vent Smoke Vent Accessories

If you would like assistance at any time about any of the rooflights or would like further details of our range, then please do not hesitate to contact us on 01276 451555, e-mail us at or use this e-mail form to contact us.