Underground car parks have a reduced impact on the urban landscape, optimising space management and the development of public areas above them. However, unlike open-air car parks, they require ventilation and smoke control systems to remove pollutants generated by road traffic, such as carbon monoxide and nitrogen oxides. In order to ensure air quality or even to remove fumes in the event of a fire, there are two options for ventilation systems in underground car parks: natural ventilation or forced ventilation.
The first, natural ventilation, involves the renewal of air in the underground car park through openings to the outside, but it has limitations in terms of space dimensions and geometries, as well as specific requirements in terms of surface area and location of openings. Forced ventilation, on the other hand, ensures air renewal through mechanical extraction, usually sized according to the total surface area of the car park or the number of parking spaces.
Although there are requirements to prevent stagnation of pollutant gases, they are less stringent in forced ventilation than in natural ventilation. In addition to duct and exhaust systems, the carbon monoxide detection control system is an essential component of a forced ventilation system. This control system activates the ventilation when gas concentrations above legal limits (typically 50 ppm in car parks with employees and 100 ppm in other cases) are reached.
In addition, smoke control systems in underground car parks are intended to ensure the safe evacuation of occupants in the event of fire. While in some locations the ventilation system is allowed to comply with certain fire resistance conditions, in other locations specific installations are required for the control of smoke caused by fire.
Amusement Logic analyses the various scenarios encountered in the underground car parks of its architectural and construction projects and determines suitable ventilation and smoke control systems to meet safety and health requirements.
For more information on smoke control systems, we encourage you to read our previous article on the subject: Smoke control systems.
By Juan Carlos Soria, Senior MEP Engineer in Amusement Logic’s Architectural Dept.
