Allergens and Indoor Pollutants: Guide for M&E Consulting Engineers

Minimising Allergens and Indoor Pollutants: Guidelines for M&E Consulting Engineers

By Ruth MacEachern

Product Manager

Recent amendments to Approved Document F, the section of the UK Building Regulations regulating ventilation and air flow in residential dwellings, have led to a heightened focus on air quality in residential new build properties. An NICE Guideline [NG149] published in January 2020 recommends that architects and designers should “minimise exposure to particulate matter” and specify “materials and products that only emit a low level of formaldehyde and VOCs”. Elsewhere the same guideline offers advice on how to reduce damp and condensation and prevent mould.

The aforementioned documents are but a small sample of the many regulations and directives targeted at improved indoor air quality, with a view to improving the health and well-being of the occupants of UK housing stock and thus relieving the burden on the NHS. Indeed, a study conducted in June 2023 by NHS England found that “the number of hay fever sufferers seeking advice from the NHS website has more than tripled”, with 122,650 visits recorded in the week prior to the publication of the analysis.

Against this context, this article will consider how to reduce allergens and indoor particulate pollutants in a new build home. In outlining strategies by which to reduce airborne allergens and harmful substances, the article will focus on three key areas: ventilation, filtration, and air quality control.

Ventilation: plan your installation at an early project stage

With amendments to Approved Document L and new guidelines under the Future Homes Standard regarding the airtightness of buildings, mechanical ventilation is not just desirable but is now a requirement. A whole-house installation such as an MVHR system will extract stale and contaminated air from the building, replacing it with a flow of fresh air from outside. This prevents the build-up of allergens and pollutants inside the home. Further information on how ventilation can prevent hay fever by cutting the amount of pollen in the home can be found here. We also have an article on how to install appropriate ventilation in rooms with no windows.

Filtration: eliminate allergens and pathogens before they enter the home

As it makes little sense replacing stale, polluted, and allergen-filled air inside the home with external air that contains the very same contaminants. Therefore, proper filtration as part of a ventilation system is essential. Many mechanical ventilation systems come complete with filtration systems to help reduce allergens in the home. It is important that homeowners are instructed on the maintenance of the filters and suitable replacement intervals. Furthermore, window and wall-mounted trickle vents with built-in anti-allergen and anti-smog filters are also commercially available.

Air quality control: effectively monitor IAQ and make necessary adjustments

It is difficult for a homeowner to know when to act if they are unaware of issues in the home concerning indoor air quality. Indoor air quality testing and air flow rate testing should be performed to ensure the efficiency of installed ventilation systems within the context of building design and construction.

In addition, there are a number of devices that can be installed to allow future homeowners to take air quality control into their own hands. VOC sensors, carbon dioxide meters, carbon monoxide alarms, and radon detectors can be used to monitor the presence of indoor particulate pollutants and VOCs. Many ventilation system control units also include devices to monitor temperature and humidity levels. Keeping a close eye on these levels can help prevent the formation of mould. If your chosen ventilation system does not include temperature and humidity sensors, room thermostats and hygrometers can be purchased and installed at a relatively low cost.

Additional measures to improve indoor air quality

Finally, there are a number of measures that can be taken by homeowners to reduce the presence of allergens and pollutants in domestic dwellings. You may wish to pass this advice on to customers purchasing your homes or projects:

• Indoor plants have been shown to reduce the presence of allergens and indoor pollutants in domestic dwellings. In March 2023 Country Living magazine produced a comprehensive list of plants that improve air quality, outlining the specific benefits of various plants and the rooms in which they are most effective.
• The use of an air purifier or dehumidifier can be an effective means by which to tackle problem areas in a targeted manner.
• It is important that owners regularly open windows to keep rooms well aired and encourage the flow of air from one room to the next and to prevent condensation.
• Recommend customers to avoid smoking in their homes and ideally use gas or electric heating.
• Tell them to vacuum on a regular basis to prevent the build-up of dust mites and other allergens.

Eliminating pathogens and allergens can significantly improve the health and comfort of future occupants and ensure compliance with applicable regulations. If you require further advice on methods by which to improve indoor air quality, information on relevant legislation, or help selecting an appropriate ventilation equipment, we have an extensive directory of online articles to help. You can also contact our EnviroVent experts for tailored consultation and advice.