Ventilation: Approved Document F, Volume 2 — Buildings other than dwellings

F1(1) O N L I N E V E R S I O N 1.39 As an alternative to paragraph 1.38, either of the following may be considered to provide adequate ventilation. a. If the car park has natural ventilation, openings at each car parking level should comply with both of the following. i. Have a minimum aggregate equivalent area of 1/20 of the floor area at that level. ii. Have a minimum of 25% of the aggregate equivalent area on each of two opposing walls. b. If the car park has mechanical ventilation, either of the following should apply. i. All of the following. • Permanent natural ventilation openings with a minimum equivalent area of 1/40 of the floor area. • A mechanical ventilation system capable of at least three air changes per hour. • For exits and ramps, where cars queue inside the building, provision to ensure a local ventilation rate of at least ten air changes per hour. ii. Both of the following. • For a car park in a basement, the provision of a mechanical ventilation system capable of at least six air changes per hour. • For exits and ramps, where cars queue inside the building, provision to ensure a local ventilation rate of at least ten air changes per hour. 1.40 Further guidance can be found in the following documents. a. The Association of Petroleum and Explosives Administrations’ Code of Practice for Ground Floor, Multi Storey and Underground Car Parks. b. CIBSE’s Guide B2 Ventilation and Ductwork. c. The Health and Safety Executive’s publication EH40/2005 Workplace Exposure Limits. d. ASHRAE’s ASHRAE Handbook – HVAC Applications, chapter 16 ‘Enclosed Vehicular Facilities’. Ventilation for buildings other than offices and car parks 1.41 Adequate means of ventilation in buildings other than offices and car parks may be demonstrated by meeting the relevant standards set out in CIBSE’s Guide A. Sources of further guidance, and relevant regulations, are listed in Table 1.1. NOTE: For residential non-domestic buildings within the scope of Part O of the Building Regulations (overheating), higher purge ventilation rates may be required. 12 Approved Document F Volume 2, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N