Good ventilation vital to COVID mitigation

Good ventilation in buildings and on transport is key to reducing the risk of Covid-19 and other infections, according to report published today (July 16, 2021).

Good ventilation
Covid-19 (Image by Tumisu from Pixabay)

The report was commissioned by government chief scientific adviser Sir Patrick Vallance and published by the Royal Academy of Engineering and its partners in the National Engineering Policy Centre (NEPC).

It found that the importance of ventilation in mitigating against COVID-19 has been overlooked and that that pandemic has revealed flaws in the way in which buildings are designed, managed and operated.

Unless they are addressed, these could disrupt management of the current and future pandemics, impose high financial and health costs on society and hinder efforts to address challenges such as climate change.

Routes to infection included exhaled aerosols from a person’s breath, sharing air in enclosed spaces, and through touching contaminated surfaces.

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“We don’t quite know yet the relative importance of these different routes – on whether that changes in different spaces – but we do know there’s hugely growing evidence that the air matters a lot more than we thought at the outset of this pandemic,” said Catherine Noakes, Professor of Environmental Engineering for Buildings at Leeds University during a press briefing on July 15.

According to the report, unambiguous communication and advice on ventilation from government and professional bodies is needed to help building owners and operators to manage infection risks. Clearly identifiable measures that can be implemented at moderate cost will help to ensure that adequate ventilation is prioritised alongside more visible measures such as surface cleaning and distancing.

“We’ve got to give people the right understanding and knowledge to understand how their buildings work and therefore understand how they can use behaviours to manage those buildings effectively, but also then use technologies to mitigate some of the risks,” said Prof Noakes. “There’s a lot of things we can do…simple improvements to building ventilation…changing airflow setpoints all the way through to putting in new ventilation systems. We can use things like air cleaning technologies – provided they’re the right ones – and touch-free systems that enable people to interact differently in buildings without having to touch surfaces. Possibly all these things bring other benefits too, for example accessibility in buildings.”

The report cautions that technological solutions are not a ‘silver bullet’, and reliance on technology can have negative consequences. Air cleaning using high-efficiency particulate air (HEPA) filters or ultraviolet light (UVC) can be effective at reducing infection risks in locations where good ventilation is difficult to achieve but the benefits are of using other kinds of air cleaning devices are less clear.

The report also warns that there is an urgent need to address skills and knowledge gaps and put in place the training, re-skilling and recruitment needed to fill them. Furthermore, investment in research and development is needed to clarify issues such as acceptable minimum standards for ventilation to support regulation by Local Authorities and others. Efforts to increase resilience to infection must also work alongside the delivery of carbon emission savings from buildings.

“In the short term we need to take some actions to manage our buildings, we need to do this now and to get those in place before next winter….and we need to urgently start planning for how we’re going to manage long term change to improve design, operation, user experiences in our buildings,” said Professor Noakes.

In 2019 ONS estimated that over five million workdays are lost to respiratory infections. An earlier study from Denmark found that good ventilation affects sleep, workplace productivity, and well-being.

Professor Peter Guthrie OBE FREng, vice president of the Royal Academy of Engineering and chair of the NEPC infection resilient environments working group, said: “Buildings make an enormous difference to people’s health and we have often neglected this in the past, which is bad news in a pandemic, because they are one of the most significant levers that we have to control infection. We must take action now to make sure that good practice in ventilation is widely understood and applied across workplaces and public buildings.

“Longer term, this is a real opportunity to transform the way we design and manage our buildings to create good, healthy and sustainable environments for those who use them.”

Key recommendations in the report include:

  • Government should urgently map the knowledge and skills requirements across the building industry, general businesses, and the engineering professions and put in place plans to address the skills gaps identified.
  • Government should undertake a rapid review of the capacity and capability requirements among regulators (including local authorities) to support and enforce standards in maintaining buildings for public health.
  • Working with the National Core Studies Programme, UKRI and the National Academies, government should put in place an action plan to address key research gaps on an accelerated basis.
  • Research and demonstration projects should be commissioned to fill key knowledge gaps such as the acceptable minimum standards for ventilation to manage infection risk and to underwrite regulation and enforcement.
  • Action to meet Net Zero must be developed in a way which is consistent with priorities around indoor air quality and making buildings resilient to infection