When it comes to corridor ventilation, two things must be taken into consideration: effective smoke evacuation in the event of a fire and preventing overheating, for day-to-day comfort ventilation.
Whilst the former is a regulated requirement in the UK, the latter provides pleasant conditions for occupants who will expect these conditions, especially if they are renting or have purchased a property within the building. Furthermore, maintaining comfortable conditions can prevent issues with maintaining cold water supply temperatures from arising.
Fortunately, once the smoke control requirements in corridors have been met, it is not a huge step to adapt the systems to prevent or overcome overheating in corridors.
In this post, we will outline how dual-purpose systems have been developed over the years to enhance corridor ventilation, keeping occupants safer whilst providing a more comfortable environment.
Smoke control in corridors
In multi-storey residential buildings, the main escape route is via corridors or lobbies that connect to the stairs. In the event of a fire, if smoke fills the stairwell, it can make it very difficult for occupants to escape. Therefore, smoke control systems are required in compliance with the recommendations of Approved Document B and BS 9991:2011.
Ventilation can be:
Corridors with external walls
Natural ventilation is the simplest and most cost-effective option where a ventilated corridor or lobby extends to an external wall. In this case, a 1.5m² Corridor AOV (Automatic Opening Ventilator) or Corridor OV (Opening Ventilator) may be used at each level. Typical AOVs include Coltlite louvred ventilators and Kameleon casement ventilators.
Ventilation shafts can be used if there is no external wall adjacent to the corridor. A single ventilation shaft may be fitted at each level with a natural ventilator (such as the Colt Seefire ventilator) at the top of the shaft.
Pressurisation systems may be used in place of natural ventilators or shaft systems. They generally provide better protection. An air supply system sustains a positive air pressure in the staircase, that prevents smoke from entering it.
Find out more about smoke control systems for multi-storey residential buildings.
Overheating in corridors
The greater emphasis on efficiency has resulted in the installation of very good insulation in residential buildings.
Whilst this is great for the environment and for electricity bills, it has resulted in unintended consequences in stairwells, lobbies, corridors and entrance halls, which can tend to overheat.
Overheating issues in residential buildings can be resolved by using smoke control systems. This is achieved by providing simple and effective cross-flow ventilation and extract warm air from corridors.
Evaporative cooling for when natural ventilation is not enough
There are some cases whereby natural ventilation will not be enough. If the temperature within a corridor is still too high despite having a ventilation system, evaporative cooling can be used to boost the effect with active cooling.
Colt’s solution: CoolShaft
We’ve developed a solution that uses evaporative cooling technology to provide active pre-cooling of the incoming air. Furthermore, in the event of a fire, it is able to ventilate the area, allowing the smoke to escape.
The CoolShaft is 4 to 7 times more economical than conventional air conditioning with the benefits of having lower costs.
Colt’s Coolshaft system is designed for each client’s individual application and is sized to suit that building’s heat load.
Please contact us if you require information relating to the application, specification, installation and servicing of CoolShaft.
Thanks for taking the time to read this post. If you have any questions or would like to discuss a project, get in touch!
Conor Logan CEng FIMechE FCIBSE is Technical Director of Colt UK. Conor designs innovative smoke control and HVAC systems, represents Colt on many UK and EU standards committees and was Chairman of the Smoke Control Association for over 9 years.