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

O N L I N E V E R S I O N C How the measurements can help you take action CO measurements should be used as a broad guide to ventilation within a space, rather than treated as 2 ‘safe thresholds’. Outdoor levels are around 400ppm. A consistent indoor CO value of less than 800ppm is likely to 2 indicate that a space is well ventilated. An average CO concentration of 1500ppm over the period when a space is occupied is an indicator of 2 poor ventilation. Action should be taken to improve ventilation if CO readings are consistently higher 2 than 1500ppm. However, in locations where continuous talking or singing takes place, or there are high levels of physical activity (such as dancing, playing sport or exercising), providing ventilation sufficient to keep CO levels 2 below 800ppm is recommended. Where CO monitors will be less effective 2 CO monitors may not be suitable for use in areas that rely on air-cleaning units because these remove 2 contaminants from the air but do not remove CO . 2 In large, open spaces and spaces with high ceilings, such as food production halls or warehouses, air may not be fully mixed and the measurements made by CO monitors may not be representative. 2 CO monitors are of limited use in less populated areas. 2 31 Building Regulations 2010 Approved Document F Volume 2, 2021 edition O N L I N E V E R S I O N