Report reveals ignorance of indoor air quality in buildings | Camfil

Air filtration in public buildings in London – Many local authorities are in the dark when it comes to knowing if their buildings use regularly maintained air filters that comply with indoor air quality standard EN 13779, particularly schools, according to a new report from Clean Air in London (CAL).

In the report, the cross-party campaigning group claims that indoor air quality (IAQ) can often be worse than outdoor (or ambient) air quality, due to the many sources of pollution that exist within buildings and homes. CAL is therefore campaigning to build public understanding of indoor air quality, initially in London, with support from us here at Camfil Farr.

The report examines the issue of air filtration in public buildings in London. It includes the results of an Environment Information Regulations request to local, regional and central Government bodies asking ‘which buildings owned, occupied or managed by the Local Authority use regularly maintained air filters that comply fully with European guideline EN 13779 e.g. offices and schools’. The responses received are analysed and ranked.

The Greater London Authority Group (GLA Group) demonstrated detailed knowledge of its buildings. However, CAL was surprised to discover that only eight of 15 buildings in Transport for London’s ‘Head Office Portfolio’ were due to comply fully with EN 13779 by April 2012 with seven others in 2012/2013 and many more having no expected compliance date. CAL has also been surprised to discover a big difference among the 33 local authorities in London in terms of how much they know about indoor air quality standards in their buildings. Some have been able to provide quite detailed information on compliant buildings whilst others seem to have little idea of which buildings comply with EN 13779. Many local authorities have told CAL they do not know about compliance with EN 13779 in some or all of their schools because they are independently managed.

CAL is therefore encouraging the London Assembly to investigate IAQ with a particular focus on health and energy savings. CAL also urges local, regional and central Government bodies to ensure all their buildings use regularly maintained, low energy, air filters that comply fully with British and European standard EN 13779. IAQ should be addressed by Directors of Public Health and the new Health and Wellbeing Boards. There is a tremendous opportunity to improve public health and save energy and money through the use of regularly maintained air filters that comply fully with EN 13779.

Clean Air in London’s vision for indoor air quality

Outdoor air quality is very poor in much of London. CAL believes that the solution to this problem is action to reduce emissions of air pollutants at their source. However, in the short term, managers of buildings in polluted areas should take steps to protect the health of those who visit or work in these buildings. Such buildings may include private sector offices and other workplaces as well as public buildings used by the general public and public sector employees. The EnVIE report estimated European citizens spend on average over 90% of their time indoors.

Children and the elderly are especially vulnerable to the impacts of poor air quality. Figures obtained by CAL show that 2,270 schools in London are within 400m of roads carrying over 10,000 vehicles a day i.e. busy, polluted roads. Schools located in polluted environments should be equipped with effective air filtration in order to maintain a healthy environment for children.

See also CAL’s guide to IAQ:

http://cleanairinlondon.org/hot-topics/indoor-air-quality-can-be-worse-than-outdoor/

About air filtration

Many buildings are now equipped with some form of mechanical air treatment system. This may be mechanical ventilation, air conditioning (heating/cooling) and/or air filtration or any combination of these (or none of them). A system may service an entire building, or just part of it.

Where air filtration systems are installed a wide variety of filter materials can often be used. Higher quality, low energy air filters, such as those made from glass fibre, designed with a large surface area to reduce pressure drop (so-called ‘bag filters’), can achieve and sustain much higher particle efficiencies at lower total lifetime cost (as energy may use up to 70% of total cost). Ultraviolet light may eliminate some pathogens but do little or nothing to eliminate particles or gases. Cheaper synthetic filter materials may depend on electrostatic charge to comply with standards initially but can lose their charge and require much more frequent replacement with all the associated maintenance and disposal costs. The efficiency of carbon filters depends on charcoal’s ability to retain gas molecules on its surface which in turn depends on the quality and surface area of charcoal and the type of gas, contact time and gas concentration.

If a building is located in an area with high levels of air pollution, filtration can be used to remove pollutants to protect the health of occupants. In these types of environment it is desirable to have a ‘sealed’ building with non-opening windows, using mechanical ventilation, air conditioning and air filtration that provides clean, filtered air to occupants.

The type of filters used in a system will depend upon the level of filtration required. For dust and particles two filters are typically used: a coarse (lower cost) filter followed by a finer, more expensive filter to remove smaller particles. If filtration of pollutant gases is required a second gas or ‘molecular’ filter will also be used. In all cases filters need to be regularly maintained in order to perform effectively.

Air filtration standards and guidance

The relevant European Standard (and also now a British Standard) for air filtration is BS EN 13779:2007, which focuses on achieving a comfortable and healthy indoor environment in all seasons with acceptable installation and running costs. The standard helps building engineers specify the quality of filtration needed by:

describing three ‘inputs’ levels for outdoor air quality – rural areas (away from sources of air pollution), smaller towns and city centres;
setting four categories for the desired ‘output’ level of air quality within the building – low, moderate, medium and high; and
recommending the level of filtration required, based upon the ‘input’ air and desired quality of the ‘output’ air in the building.

Buildings located in an unpolluted rural area only require a single stage particle filter to maintain medium or high indoor air quality. However, for buildings located in a polluted city centre, two stage particle filtration and a gas filter will be needed to achieve the same result. More information about EN 13779 can be found at www.camfilfarr.co.uk/Filter-technology/Specifications-and-Regulations/EN-13779.

Guidance produced by the City of London, as part of its CityAir programme, recommends the use of EN 13779. CityAir provides guidance and advice for businesses operating in the City of London area (and elsewhere) The CityAir guide for building engineers and facilities managers states:

Air conditioning and filtration

Improving indoor air quality is also an important consideration in increasing employee wellbeing: Ensure that your air filters are regularly maintained and comply with EN 13779*
Install low energy two stage particle and gas filters for maximum effect and cost savings

* It is a legal requirement to inspect all air conditioning systems with a rated output over 12kW at intervals not greater than 5 years

Analysis

CAL’s survey reveals that building management varies significantly between public bodies. Centralised bodies such as the GLA Group were able to provide detailed information on compliance with EN 13779 across their property portfolios whilst other bodies were either unwilling or unable to provide this information, presumably due to a lack of central information on their properties.

This situation is particularly acute with regard to schools. Most local authorities told CAL that their school buildings are independently managed e.g. by the schools themselves. Whilst CAL understands the logic of devolving building management to schools there is a question mark over whether individual schools are receiving appropriate advice on compliance with EN 13779 and the need for air filtration (if they are located in areas of poor air quality).

For local authorities that provided information on schools compliant with EN 13779 it is possible to calculate the proportion of their schools that comply. For example Newham’s website states that there are 100 state schools in the borough – 36 have EN 13779 compliant air filtration i.e. 36% of schools. However these figures may tell us more about the age of school buildings than whether the local authority is addressing poor indoor air quality, with new school buildings far more likely to be mechanically ventilated (hopefully with air filtration) than older buildings.

CAL believes that all public buildings in areas of poor air quality need adequate air filtration in order to provide a healthy environment for their occupants. However, an initial focus should be on buildings where occupants are especially vulnerable to the impacts of air pollution, such as schools. It is evident from CAL’s enquiries that most local authorities do not know if their schools have adequate air filtration, and more research is needed to ascertain which schools are located in areas of poor air quality in addition to guidance for school managers on providing clean, healthy air in their buildings.

For more information and to view the full report results click here .

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For more information and references:

New report reveals ignorance over indoor air quality in public buildings

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