Indoor Air Quality

Indoor Air Quality (IAQ) refers to the air quality within and around buildings with particular emphasis on how it relates to the health and comfort of occupants.

BESA formed an IAQ Action Group two years ago with a view to providing clearer technical guidance for members and the industry at large on this important topic and also to raise awareness at government level, with the general public, and across the sector through its marketing and PR departments.


Work so far

The IAQ Group was set up in response to growing alarm across the UK about rising levels of OUTDOOR air pollution.

It was clear that as air pollution worsened there would be a growing problem in buildings unless measures were taken to ensure ventilation and air conditioning systems were adequately designed, installed and (most importantly) maintained to protect occupants.

The growth in the volume and nature of outdoor contaminants is adding to the problem already created by indoor sources of air pollution.

The Group was set up specifically to be collaborative across the building services sector and, therefore, includes members and representatives of other like-minded organisations including CIBSE; BSRIA; the Construction Products Association; the City of London Corporation etc. and with charities such as Close the Door and Clean Air in London.

It has succeeded in bringing key players across the sector together and pooled their expertise in a series of press articles and technical bulletins. The next aim is to produce further technical updates, which will be freely available to members and, eventually, a comprehensive Guide to Good Practice jointly published with BSRIA and CIBSE.

It has published a series of trade press articles and responded to government consultations. It has also hosted and sponsored several technical seminars and provided expert IAQ speakers at industry events including those aimed at specialist audiences like NHS Estates managers and school ventilation engineers.

Click here to view our 'Smart Answer to Indoor Air Quality' webinar. 


Aims and ambitions

Most service and maintenance programmes already include an annual inspection of air handling units and a visual check of ductwork cleanliness, but has no specific measuring process of the actual air in the occupied space.

The Group is now advising contractors, FMs and building clients to take the relatively easy step of extending visual inspections to taking air and microbiological samples to measure the air quality and the cleanliness of ventilation; and inspecting ventilation and air conditioning filters.

Building managers are encouraged to measure and monitor: relative humidity (RH); ventilation rates; possible mould build up; temperature; CO; CO2; VOCs; supply side particulates; NO2 and NOx.  Local factors like heavy traffic levels and Radon gas should also be taken into account.


Technical sub-committee

The Group has set up a small technical group looking into what relevant technical guidance is already available; what legislation (national and international) has a bearing on IAQ; and what steps building engineering services firms could take to support clients.

The main purpose of this work will be to produce practical steps that can be used to supplement the Association’s widely used building service and maintenance tool SFG20.

The committee is proposing a range of relatively low cost, simple remedial measures –such as cleaning intake grilles and upgrading/changing filters – linked to a building ‘classification’ system i.e high, medium and low risk based on a building’s function and characteristics.

Healthcare facilities and many schools are considered high risk; a standard commercial office medium risk; and a storage facility low risk. Where the building is located – near a busy road etc. – and local conditions would be the other main factors.

It is recommending existing sources of guidance including BESA’s own ‘Guide to Good Practice – Internal Cleanliness of Ventilation Systems’ (TR/19).  The group is also looking at the behaviour of building users including opening windows in highly polluted urban areas and the impact that has on IAQ.

Measurements have shown that a well-sealed building envelope and effective filtration of incoming supply air can reduce particle penetration by 78%. There has been a growing interest in airtightness testing to help improve energy efficiency, but that process can also be used to measure IAQ.

For more information and to get involved in this work visit the BESA IAQ LinkedIn page or email: