GUIDANCE | INDOOR AIR QUALITY BREATHING SPACE New guidance designed to assess and improve indoor air quality has been published by the Institute of Air Quality Management, with input from CIBSE. Co-authors Emma Gibbons and Chris Rush explain how a new assessment approach aims to identify issues affecting air quality I n the UK, there is little legislation to protect the public from indoor exposure to air pollution, despite the existence of legal limits relating to outdoor exposure to air pollution and occupational exposure. The Institute of Air Quality Management (IAQM) has published new guidance on indoor air quality (IAQ) to fill some of these gaps in legislation and guidance. CIBSE has endorsed the final publication and its members contributed to the writing of the guidance. The IAQM was keen to involve and have the endorsement of CIBSE, given the integral role that ventilation plays in IAQ. The document provides guidance on assessment, monitoring, modelling and mitigation of IAQ, and is set out in sections relating to typical project stages. Assessment criteria are summarised and a new assessment approach is proposed, and there is also context for the guidance and a reflection on why IAQ is important. The summarised assessment criteria are based on a review of existing air quality standards in legislation and guidance, and a consideration of the likely length of exposure for the people being considered. The assessment approach requires input from all those involved in the design, construction or operation of a building, and the method can be applied to proposed, new or existing buildings. It is considered that an IAQ assessment will be needed for any building where there are internal sources of pollution, or where there is ingress of ambient (outdoor) pollutants, and where there are people in the building who could be exposed to those air pollutants. In THE FOUR STAGES OF ASSESSMENT The proposed assessment method involves the following stages: Stage 1 Scoping study. To review all available information, identify pollutants of concern and possible receptors, and determine whether a more detailed assessment is required. Stage 2 Assessment. This stage can be a simpler approach, by which the likely risk of exposure monitoring and/or modelling. Stage 3 Consideration of mitigation and improvement opportunities. Stage 4 Reporting. The assessment approach requires input from all those involved in the design, construction or operation of a building some cases, assessment may be required for non-human receptors, such as in a data centre. Elements to consider during an assessment include pollutant sources, building activities (equipment and cleaning, and so on) and the building design. Aspects of the building design that can have an effect on IAQ include: the materials used; room volume; the ventilation strategy (including, for mechanical ventilation, the hours of operation, recirculation, and air change rate); effectiveness of air distribution and airflow; the capacity of a room; and the heating/cooling strategy of the building. Air quality input should be provided at every RIBA stage, and an example of how air quality can input into a project at different RIBA stages is outlined. 24 December 2021 www.cibsejournal.com CIBSE Dec21 pp24-25 IAQ guidance.indd 24 26/11/2021 14:38