Lobby Vent Kits
Lobby Vent AOV Kits
A lobby vent or lobby AOV system is an automatic opening ventilator (AOV) that provides at least 1.5m² geometric free area when open. The installation is located at high level in the corridor or lobby that connects to the communal escape stairwell.
The lobby ventilator usually serves one of two purposes; removing any smoke that gets in the corridor or lobby of small buildings or more commonly, it provides replacement air for a lobby smoke extract system in large buildings.
If a fire breaks out, resulting in smoke getting into communal lobbies or corridors adjoining the escape stairwell, there needs to be some means of removing smoke from these areas to prevent contamination of the escape stairwell.
Compliance with Building Regulations
When it comes to lobby ventilation, paragraphs 3.49 of Approved Document B of the Building Regulations 2019 details the requirements for smoke vents for common escape routes:
Except in buildings that comply with Diagram 3.9, the corridor or lobby next to each stair should have a smoke vent. The location of the vent should comply with both of the following:
- Be as high as practicable.
- Be positioned so the top edge is at least as high as the top of the door to the stair.
They should be located on an external wall with minimum free area of 1.5m².
A vent to the outside with a minimum free area of 1m² should be provided from the top storey of the stair.
In single stair buildings, smoke vents on the storey where the fire is initiated, and the vent at the head of the stair, should be activated by smoke detectors in the common parts.
In buildings with more than one stair, smoke vents may be activated manually. The control system should open the vent at the head of the stair before, or at the same time as, the vent on the storey where the fire is located. Smoke detection is not required for ventilation purposes in this instance.
In practice, it is customary to provide a manual switch for fire and rescue service use at the access level within the stairwell for all stairwell smoke vents. Smoke vents must comply with BS EN 12101-2:2017 – Smoke and heat control systems. Natural smoke and heat exhaust ventilators; and be CE/CA marked.
Lobby ventilator control requirements
Lobby vents must be provided with a standby power source, CE marked to BS EN 12101-10:2005 – Smoke and heat control systems. Power supplies. This will usually take the form of a battery backup supply housed within a control unit. Additionally, control panels should be certified to ISO 21927-9:2012 – Smoke and heat control systems. Specification for control equipment.
Note that the stairwell vent should be activated automatically when a lobby ventilator is opened so controls will be networked.
The EV-301 control panel that features in the AOV kit range meets all of the above standards and is designed to be networked to give the correct control sequence. There are many additional features that can be added to the panel including thermostatic control and wind and rain-sensing control for summer ventilation.
Lobby vent AOV Kit options
There are several models available within the AOV kit range that are suitable for lobby ventilation including glazed units for internal daylighting and aluminium vents for thermal insulation. We do not recommend single skin aluminium ventilators as these are likely to result in condensation inside the building.
View alternative AOV Kits
AOV Kits A, B, C & H are suitable for stairwell ventilation. Find out more about each kit.
Automatic Opening Vent Kits E, F & G are suitable for smoke shafts. Find out more about each kit.