Prof Cath Noakes backs a culture change around how ventilation systems are designed and their effectiveness is measured concerning health outcomes and environmental impacts
Efforts to ensure sufficient ventilation rates across the UK’s varied building stock poses a complex challenge to address not only vital issues of occupant health and wellbeing, but also decarbonisation.
Professor Cath Noakes OBE, a deputy director of Leeds Institute for Fluid Dynamics, has told the 2021 BESA National Conference that there is no magic bullet solution to tackling indoor air quality and poor ventilation. She said that this applied both to how ventilation can limit infection risks from current health priorities such as Covid-19, as well as addressing longer-term issues about the overall wellbeing of occupants.
She said, “This has all got to be tied in to net zero. There is a huge focus, especially with COP26 around net zero. But we cannot just make buildings compliant with this net zero agenda by sealing them up. We have to make sure they are ventilated as well and make sure we balance the needs of people and the environment together.”
Professor Noakes was speaking during a session about learning from the ongoing Covid-19 pandemic and how best to enable more infection resilient indoor environments.
A major theme of the discussion was that prior to the onset of the Covid-19 pandemic in 2020, infection control had rarely if ever been a consideration for ventilation and air quality standards in buildings outside of the healthcare sector.
Professor Noakes argued that issues around comfort and energy use traditionally have been the main drivers for ventilation use in buildings. This had been followed by a more recent shift to the industry considering air quality and how it impacts productivity and wellbeing in occupants.
There was now a growing need across industry for understanding where there is either sufficient or insufficient industry skills and knowledge on tackling and understanding the different roles ventilation plays in ensuring a sustainable and well-ventilated indoor environment, she added.
The SAGE view on ventilation
Professor Noakes is also a member of the government’s Scientific Advisory Group for Emergencies (SAGE) that is focused on advising policy makers during emergencies such as the pandemic.
From this role, she identified ventilation as being a significant method of controlling potential infection risks. However, alongside other Covid-19 mitigation strategies such as wearing masks in enclosed environments, every solution was imperfect and needed to be considered as a holistic strategy that mixed multiple measures together to improve protection.
The Royal Academy of Engineering had since been commissioned by Government Chief Scientific Adviser Sir Patrick Vallance to undertake a rapid review of evidence and data looking at how buildings and infrastructure could be made more resilient to infection. One aim of the resulting review was to understand and detail recommendations ahead of this winter for tackling infection risks such as through minimum ventilation standards.
The review was conducted via the academy’s National engineering Policy Centre in collaboration with CIBSE to look at the strategic challenges of addressing infection risks along with determining what immediate action was possible based on evidence from owners and occupiers of different building types in the UK.
Professor Noakes said the review uncovered a range of different knowledge levels among building operators that resulted in very different approaches around how best to mitigate and understand transmission risks.
A lack of uniform guidance and skills was among the major concerns raised.
Ventilation was identified as a major challenge in terms of the limited levels of understanding outside of the industry about how it works, said Professor Noakes.
She said, “Organisations which said they didn’t know what good ventilation is had many different metrics to measure it and they struggled to figure this out.”
A legacy of poorly maintained buildings that impacts a range of different functions outside of ventilation was also highlighted in the academy’s findings. These maintenance issues were attributed to a range of factors such as changes in occupancy and other individual works carried out over the lifecycle of a building without recognition of the wider impacts on other systems.
Professor Noakes added, “There are some systemic issues that mean many of our buildings don’t comply with what they should do. We have a lot of buildings that are under ventilated and there’s really not an excuse for it – they just do not have what they should have.”
Another concern was technology systems being installed in buildings without informing occupants and operators on how to effectively make use of them, Professor Noakes said.
She said, “I think there is a long legacy of addressing problems in isolation and particularly thinking about addressing the energy performance of building without thinking through the health consequences of that.”
“Ultimately, I think we will probably all need to think of things around training and skills.”
Professor Noakes said she had been encouraged following the academy review by some of the government guidance and advice from the Health and Safety Executive (HSE) that had since been published. She said these different pieces of guidance highlighted the importance of ventilation use and the types of action that can be taken to identify and address poorly ventilated spaces.
There was also recognition of guidance set out by CIBSE looking at air cleaning technologies and ventilation.
However, a longer-term issue still remains over improving knowledge and awareness about what makes a good indoor environment with regard to air quality. This issue is expected to touch on new ways of defining clear ventilation rates and understanding how this can be introduced to meet the specific needs of an individual building.
Part of this challenge was in the complexity of understanding and effectively measuring air quality, according to Professor Noakes.
She said, “This is especially the case in naturally ventilated buildings. But even if we know what it is and we can measure this, being able to say what is the right ventilation rate and metric for health in a building is not easy. It’s very difficult to relate ventilation rates to health consequences. “
“Then we also have a challenge linking ventilation to user behaviour. So a lot of buildings rely on opening windows and peoples’ motivations to do this are usually not around air quality, but around comfort, noise and security. We do need to think much more about the motivations for why people ventilate spaces and how people interact with systems in their buildings.”
When questioned on the possible role of revised regulations to help enforce new ventilating standards and rates, Professor Noakes said she did believe there was a role for fresh legislation.
She said, “We can all grumble about legislation and pick holes in it, but at the end of the day, when regulation is there and enforced it does usually make a difference.”
“Tt is certainly one driver, but I do think we need to be thinking about other ways that we can demonstrate best practice and some of this is not going to be about showing you have complied with regulation, but instead showing a client that actually there is a real cost benefit from having a better ventilated environment for employees and for the health and wellbeing of people.”
Professor Noakes added, “This is a really hard thing to put numbers to.”
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