Natural Car Park Ventilation Area Calculator
Download our tool and calculate the area of natural ventilation needed for the size of your car park.
Natural Car Park Ventilation Area Calculator
Natural car park ventilation requirements
Natural ventilation simply requires permanent openings to fresh air being provided equal to a percentage of the floor area of the car park. It is permissible to have openings into the ceiling as part of the ventilation area along with ramps where these are open and not obstructed by roller shutters. Opening ventilators may be used to provide the ventilation and these should comply with BS EN 12101 Part 2 and the free area of the ventilators must be taken into account.
The ventilation areas required are:
- 5% for ventilation of everyday vehicle pollution and smoke with at least 50% being provided between opposite faces of the building; the openings provided must be sufficient to create a through draught.
- 2.5% for smoke clearance only with at least 50% being provided in opposite faces of the building.
- If only 2.5% is provided a supplementary mechanical CO ventilation system will be required to limit the concentration of CO within the space.
This method relies on a path to the outside being freely available, which is not usually the case for underground car parks, where a mechanical extract system is often required.
