‘Safe havens’ can help the recovery and save lives
Turning buildings into ‘safe havens’ from pollution and airborne viruses will play a big part in giving people confidence to return to their offices, restaurants, gyms and other public buildings, but it will also have wider benefits, says Nathan Wood of BESA.
One positive outcome of the Covid crisis has been the increased focus on improving ventilation of indoor spaces and the need to measure indoor air quality (IAQ). This will not only be vital in giving people confidence to return to public buildings – it will contribute to the economic recovery and ultimately save lives.
Apart from the health impacts, poor air quality also reduces productivity, shortens the operating life of capital equipment, and increases maintenance costs, according to research carried out by CBI Economics on behalf of the Clean Air Fund.
The business organisation also said that improving air quality should be a key part of the UK’s journey to net zero and that meeting World Health Organisation (WHO) air quality guidelines by 2030 was “a crucial element of the green recovery”.
The Covid-19 emergency has thrust the ventilation of buildings into the limelight. For so long a ‘Cinderella’ service, it is now a topic of urgent discussion and building managers are facing detailed questions about how they are improving airflows to help dilute airborne viral loads.
Professor Cath Noakes from the University of Leeds is a ventilation specialist and one of only two engineer members of the Scientific Advisory Group for Emergencies (SAGE) that has been helping the government navigate the pandemic.
She is determined that the industry takes advantage of this increased awareness to ensure buildings are protected for the long-term so that after the current crisis has subsided, we don’t slip back into accepting poorly ventilated spaces with high levels of indoor contaminants.
Speaking at a recent webinar hosted by the Building Engineering Services Association (BESA), she said there was still much to learn about how ventilation can protect building occupants from viruses and other airborne threats, and that settling on a ventilation strategy was not straightforward.
“This is a very complex issue, and it will take years to build up the amount of data needed to make sure we can do this better. However, as a rule of thumb we should aim for [air change rates of] 10 litres per second (l/s) per person and CO2 concentrations below 800 parts per million,” she said.
Professor Noakes confirmed that studies had shown the risk was higher indoors when ventilation provided less than 3 l/s per person and that household transmission was a particular concern. She also explained that the virus thrived in cool, dry, and dark conditions – making humidity control another priority.
We are also becoming increasingly aware of a real problem building up in homes. Some domestic ventilation systems are a terrible mess and are likely to create a major health scandal. This does not just cause unnecessary suffering and death; it is a huge financial burden on the country – the NHS in particular. There are also other social consequences to consider such as the impact on people’s quality of life and ability to earn a living.
Air quality specialist Craig Booth told another BESA webinar that the country was creating “a new type of slum” defined by appalling indoor conditions. “We are seeing some terrible installations in homes and need to do much better,” he said – referring to the misuse of mechanical ventilation with heat recovery (MVHR), in particular.
“Manufacturers are getting the blame for noisy and ineffective systems, but often it is the installation that is wrong with flexible ducting being squeezed into inappropriate spaces,” said Booth, who is a member of BESA’s Health & Wellbeing in Buildings committee.
“The Covid crisis has raised awareness of IAQ and demonstrated that well designed, installed and operated ventilation systems can tackle both internally and externally generated contaminants. This will be key to delivering bio-security in buildings as we seek to emerge from lockdown,” he said.
The importance of this issue was highlighted in a coroner’s report in April. Philip Barlow called for new legally enforceable lower air pollution limits in line with World Health Organisation (WHO) guidelines to prevent as many as 40,000 excess deaths in the UK every year.
Currently, UK limits on some harmful particulates are twice as high as those recommended by the WHO.
Barlow was the south London coroner who ruled that air pollution had contributed to the death of nine-year-old Ella Kissi-Debrah. This led to his ‘Prevention of Future Deaths’ report and its hard-hitting recommendations to the government.
“The evidence at the inquest was that there is no safe level for particulate matter and that the WHO guidelines should be seen as minimum requirements,” said Barlow. “Legally binding targets based on WHO guidelines would reduce the number of deaths from air pollution in the UK.”
The title of the report is very important and should remind every building engineer why our work matters. We have a moral obligation to use all our skills and the engineering tools at our disposal to make changes now inside buildings because people, many of them children, are dying.
Nathan Wood is Chair of the BESA Health & Wellbeing in Buildings Group.