8 things you should know about ventilation & air quality
Friday 8th November is World Ventil8 Day, which aims to raise awareness of the importance of ventilation in the health and wellbeing of people.
Ventilation comes in many different forms, from natural ventilation such as windows, through to whole house ventilation systems, and air handling units for commercial properties. Unless you are in the industry, for the majority of people, ventilation rarely receives much attention. Yet without effective ventilation, our buildings become unhealthy, unpleasant environments to be in. In recognition of World Ventl8 Day, here we address eight aspects of ventilation and air quality that deserve a closer look:
- Our air is polluted
In the UK, air quality laws are based on a combination of international commitments, retained EU law and domestic legislation. Under these, annual average concentrations of NO2 – one of the most harmful pollutants – cannot exceed 40 µg/m3 (micrograms per cubic metre of air). When it comes to concentrations of Particulate Matter (PM), there is a maximum annual average legal limit of 40 µg/m3 for PM10 and 20 µg/m3 for PM2.5. In the most recent annual air quality assessment (for 2023), the UK was non-compliant with the annual mean concentration limit value for NO2 at a number of roadside locations in urban areas. This is particularly concerning when you then consider WHO’s Global Air Quality Guidelines, which were revised in 2021 based on latest evidence on health effects from exposure to air pollution. The WHO recommended guideline for annual average NO2 pollution is 10 µg/m - four times lower than the UK’s limit. For PM2.5, it’s 5 µg/m3 – not the 20 µg/m set in the UK. - Indoor air quality is under researched
We spend most of our time indoors – between 80-90% - yet little research has been done into indoor air quality (IAQ) when compared to external air pollution. Indoor pollutant sources vary hugely. We not only have to contend with external emissions entering our properties, but we also have pollutants which are generated within them, such as cleaning products, furniture, the fabric our buildings are made from, and everyday activities such as cooking within our homes. Individually, these potentially pose a risk to health, but when they react together that risk may well become considerable heightened; sadly, there’s very little research in this area, so we are rather in the dark. What we do know is that good ventilation can disperse and expel indoor pollutants. - ‘Green’ cleaning products aren’t necessarily low in VOCs
Personal care and household cleaning products are frequent emitters of VOCs, even many labelled as ‘eco’ or ‘green’. Research conducted by IMPeCCABLE and published by The Royal Society of Chemistry found that many fragranced cleaning products labelled as green emit just as many harmful chemicals as regular products. The source of the problem stems from the fragrance ingredients which can be harmful to people susceptible to respiratory conditions, and can also lead to irritation of the eyes, nose, throat, or skin. - Poor air quality impacts health
Poor air quality, whether indoor or out, is well known to impact our health. The obvious risk to health is respiratory based, which has the greatest impact in the young, old and those with existing respiratory conditions, including asthma. But it goes much further than that. Air pollution can harm every organ, can shorten our lives, and contribute towards chronic illness. When we breathe polluted air, it can inflame the lining of our lungs and move into our bloodstream ending up in the heart and brain, causing lung disease, heart disease, dementia and strokes. Condensation, damp and mould are also a measure of IAQ. An estimated 904,000 homes in England alone had damp problems in 2021 according to the English Housing Survey. Damp and mould are dangerous. In December 2020, two-year-old Awaab Ishak died from prolonged exposure to mould in his home in Rochdale. Such was the strength of feeling, that Awaab's Law has been introduced as part of the Social Housing (Regulation) Act, which requires social housing landlords by law to fix damp and mould issues to strict deadlines. - Children are disproportionally impacted
Children are more likely to be admitted to hospital with respiratory problems caused by air pollution than adults. Furthermore, the damage to their lungs is irreparable as immature lungs are more susceptible to toxins. In children air pollution also affects neurodevelopment, leading to lower cognitive test outcomes, negatively affecting mental and motor development. - Schools need to be better protected from pollutants
Schools should be a safe place to learn, yet 86% of new schools in England are in areas breaching World Health Organization (WHO) air pollution limits; that’s 147 schools built or to be built between 2017 and 2025. Sadly, there is no legal requirement for air pollution to be considered in planning for new schools despite children spending on an average 35 hours a week at school for half the year.
Following a recent study at a school in Cardiff, University of Birmingham researchers have shown the main source of Particulate Matter pollution – the most dangerous common pollutant - within classrooms originates outside the building. The levels of pollution are impacted by the lesson activities and frequency, whether the room was carpeted or hard floored, and the classroom’s location within the school. - Building Regulations has increased ventilation rates in our homes
Changes to Building Regulations ‘Approved Document F, Volume 1: Dwellings’ (ADF1) came into effect on 15th June 2022. Across all sizes of dwellings, minimum ventilation rates were increased, with the aim of ensuring every part of a home, especially the bedrooms, are adequately ventilated. Across all size properties, ventilation rates have been increased by up to 48%, which is considerable. To achieve these new ventilation rates, mechanical ventilation systems are the most proficient option. - Ventilation tackles both old and modern issues
Good ventilation is not only important to remove condensation and help prevent the formation of mould, which are age old problems in the UK, but is a vital means of tackling a new issue in our housing stock: overheating. Under the Chartered Institution of Building Services Engineers’ (CIBSE) ‘TM59 Design methodology for the assessment of overheating risk in homes’, overheating is defined as when the internal temperature threshold of 26°C is surpassed for over 3% of the summer period (1st May – 30th September). Using the TM59 standard, a 2019 government study on overheating in homes showed that out of eight modelled house and flat typologies, not a single one met the acceptable risk criteria for overheating. Flats are particularly susceptible to overheating. Areas within our homes most likely to overheat are living rooms, bedrooms, conservatories and loft conversions. Building Regulations Approved Document O recognises ventilation as part of the cooling ‘hierarchy’ to remove heat from the indoor environment.
If you would like to find out more about World Ventil8 Day, go to https://www.worldventil8day.com/
