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 Table 2.1 L imit values from Schedule 2 to the Air Quality Standards Regulations 2010 Pollutant Exposure limit Exposure time Carbon monoxide 10mg/m3 8-hour average Sulphur dioxide 350μg/m3 1-hour average 125μg/m3 1-day average Nitrogen dioxide 200μg/m3 1-hour average 40μg/m3 1-year average Benzene 5μg/m3 1-year average Lead 0.5mg/m3 1-year average PM 25μg/m3 1-year average 2.5 PM 50μg/m3 1-day average 10 40μg/m3 1-year average NOTE: This section only gives guidance for typical situations. Expert advice may also be able to provide additional guidance on the suitability of other technologies to minimise the intake of external air pollutants, including filtration. NOTE: The Building Research Establishment’s Ventilation for Healthy Buildings: Reducing the Impact of Urban Air Pollution provides guidance on minimising the ingress of external pollutants into non- domestic urban buildings. Control of ventilation intakes 2.2 Ventilation intakes should be located away from the direct impact of the sources of local pollution. NOTE: CIBSE’s TM64 and TM40 give further guidance. 2.3 Where urban traffic is a source of pollution, the air intakes for buildings next to busy urban roads should be both of the following. a. As high as possible. b. Located on the less polluted side of the building. Mechanical ventilation may be the most practical way of achieving this requirement. 2.4 If practicable, ventilation intakes should not be located in courtyards or enclosed urban spaces where air pollutants are discharged. If this is unavoidable, intakes should be located to meet both of the following conditions. a. As far as possible from the source of pollutants. b. In an open or well-ventilated area. 2.5 In areas where wind often comes from opposing directions (e.g. a valley), the air intakes should point in the opposite direction to the exhaust outlets. 2.6 Where sources of pollution vary with the time of day, such as urban road traffic, it may be acceptable, for time-limited periods, to take one of the following actions. a. Reduce the flow of external air into ventilation intakes. 16 Approved Document F Volume 2, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N