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

O N L I N E V E R S I O N B Assumptions used in applying performance criteria for offices in Section 1 General B4 For the purposes of this approved document, for all offices (both new and existing, where Part F applies), the moisture criteria are likely to be met if, during the colder months of the year, the moving average surface water activity of the internal surfaces of external walls is always less than the value in Table B2, evaluated over each moving average period. Table B2 Surface water activity Moving average period Surface water activity 1 month 0.75 1 week 0.85 1 day 0.95 Extract ventilation B5 Office equipment can emit pollutants, including ozone and organic compounds. For example, a study by Black and Wortham (1999) suggests the following emission rates for laser printers and dry paper copiers assuming 30 minutes use in an hour. a. 25mg/h for TVOC. b. 3mg/h for ozone. To meet the performance criteria for these pollutants requires an extract rate of 20 litres per second per machine during use. B6 For sanitary accommodation, the extract rates used for dwellings have been applied. B7 For food and beverage preparation areas, the extract rates used for dwellings have been applied. 29 Building Regulations 2010 Approved Document F Volume 2, 2021 edition O N L I N E V E R S I O N