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

O N L I N E V E R S I O N F1(1) Purge ventilation for offices 1.35 Each office should have the means to provide purge ventilation, to reduce pollutants before the office space is occupied or after activities such as painting. The purged air should both: a. be taken directly to the outside b. not be recirculated to any other part of the building. Controls for offices 1.36 Controls should be provided for ventilators so that the ventilation in each room can be adjusted. For mechanical supply and extract ventilation, either manual controls or automatic controls are acceptable. Recirculation of air within ventilation systems in offices 1.37 Ventilation systems that, under normal operation, recirculate air between more than one space, room or zone should also be able to operate in a mode that reduces the risk of the transmission of airborne infection. This can be achieved by one or more of the following. a. Systems capable of providing 100% outdoor air to the levels specified in paragraphs 1.32 to 1.34 to all occupiable rooms and common spaces, without recirculating air. b. Systems incorporating a UV-C germicidal irradiation system that is able to disinfect the air that is being recirculated. This type of system is commonly located within the heating, ventilation and air conditioning (HVAC) system or ductwork. c. Systems designed so that they can incorporate HEPA filters, if required, which are able to provide filtration of the recirculated air. NOTE: For some system types some recirculation is necessary or desirable in normal operation. Use of any full outdoor air mode, UV-C germicidal irradiation or HEPA filtration may not be necessary under normal conditions of operation. Ventilation of car parks 1.38 For car parks below ground level, enclosed car parks and multi-storey car parks, the ventilation rate should be designed, and equipment installed, to limit carbon monoxide to both of the following. a. Average concentration: a maximum of 30 parts per million over an eight-hour period. b. Peak concentration, such as by ramps and exits: a maximum of 90 parts per million over a 15-minute period. NOTE: Guidance on the ventilation of car parks to manage the risk of fire is given in Approved Document B. 11 Building Regulations 2010 Approved Document F Volume 2, 2021 edition O N L I N E V E R S I O N