Ventilation and air purification during Covid

Enclosed spaces like schools can become breeding grounds for the Covid-19 virus, which can linger in the air. The focus for schools is to increase ventilation, as well as adopt technology that can remove airborne virus particles. But what help and support is available for schools?

Schools are being asked to keep their premises well ventilated to combat the spread of the coronavirus. This is because the Covid virus mainly transmits via airborne particles, and so enclosed spaces like schools can become breeding grounds for infection. Well ventilated spaces meanwhile dilute the virus, reducing the risk of spread.
In the latest operational guidance, schools are asked to identify any poorly ventilated spaces as part of their risk assessment and take steps to improve fresh air flow in these areas, giving particular consideration when holding events where visitors are on site, for example, school plays.
Mechanical ventilation is a system that uses a fan to draw fresh air or extract air from a room. These should be adjusted to increase the ventilation rate wherever possible and checked to confirm that normal operation meets current guidance and that only fresh outside air is circulated.

If possible, systems should be adjusted to full fresh air or, if this is not possible, then systems should be operated as normal as long as they are within a single room and supplemented by an outdoor air supply.
Where mechanical ventilation systems exist, you should ensure that they are maintained in accordance with the manufacturers’ recommendations.
Opening external windows can improve natural ventilation, and in addition, opening internal doors can also assist with creating a throughput of air. If necessary, external opening doors may also be used. However, schools should balance the need for increased ventilation while maintaining a comfortable temperature, especially now in the winter months.

CO2 monitors and air purifiers

CO2 monitors are being provided to state-funded education settings, so staff can quickly identify where ventilation needs to be improved.
CO2 is released when we breathe out, so higher levels of CO2 means there is higher occupancy and lower ventilation, and can be an important red flag to identify areas of inadequate ventilation.
The DfE said at the time that the monitors “will enable staff to act quickly where ventilation is poor and provide reassurance that existing ventilation measures are working”

Feedback from schools suggests that the 350,000 carbon dioxide monitors rolled out across the country are acting as a helpful tool to manage ventilation.

The Department for Education is also supplying air purifiers for schools where quick fixes to improve ventilation are not possible.     

Air purifiers can remove harmful particles, pollen and other allergens that can cause harm.

Last year, the DfE announced 1,000 air purifiers for special schools and alternative provision settings, and have recently announced 7,000 more for other schools.
Dr Mary Bousted, Joint General Secretary of the National Education Union, has said it’s not good enough however. She said: “Seven thousand more air purifiers is something, but it is completely inadequate for what should be a basic human right, the provision of clean air in every classroom in every educational setting. The fact that the Government has provided the extra purifiers shows that it recognises the problem but with over 300,000 classrooms in England it has failed to provide an effective solution.”
The DfE has also launched an online “marketplace” for schools not eligible for DfE funded purifiers to buy their own.

Trialling air purifiers

The Department for Education is currently running a trial of air purifiers in 30 schools in Bradford, to assess whether they can reduce the risk of transmission.

The research is being conducted by the Centre for Applied Education Research – a collaboration involving the universities of Leeds, Bradford and York, Bradford Council and the Department for Education.

Thirty primaries are involved in the randomised trial, with a third equipped with high-efficiency particulate air (HEPA) filters, a third with UV purifiers and the final group continuing without any special equipment.

In the schools with devices, the kit will be placed in any room that staff or children are spending substantial time in.

It is hoped the air purifiers and UV lights will also help reduce absence due to cold and flu infections, and improve the air quality for those with asthma and hay fever.

Professor Mark Mon-Williams from the School of Psychology, at the University of Leeds said: “Research has suggested that children have lost as much as half a year of schooling because of the disruption caused by the pandemic.

“There is an urgent need to identify technologies that could be adopted by schools to try and stop the spread of COVID-19. We know that good ventilation can help disperse the aerosols that can cause infection, but in a busy classroom ventilation alone will not be enough.  

“Environmental technology offers a potential solution - it will enable schools to operate as normal as possible and hopefully reduce the risk of coronavirus spreading among pupils.”

Bowling Park Primary School in Bradford is one school taking part in the study. Headteacher Matthew Langley said: “Good attendance is key to children being successful at school. As for many schools, COVID-19 caused huge disruption to Bowling Park Primary School. Repeated lockdowns created very real challenges for our children, families and staff as we all worked together to continue learning from home, but the greatest problems were caused by individual cases of COVID-19 that led to bubbles, classes or groups of classes, being closed for up to 10 days at a time.  

“Despite our very best efforts, our school had over 30 bubble closures last year.  

“We are delighted to be part of this pilot study. All our classrooms are now fitted with air filters designed to remove airborne viruses and improve air quality for children and staff. It feels like a real step forward for us as we return to normal and try to make school as safe, consistent and positive for all our children, families and staff.”

The technology

The devices used in the Bradford trial use HEPA (High Efficiency Particulate Air) filters. These trap unwanted particles such as dust, pollen, bacteria, viruses and hair from the air while allowing clean air to be pushed back out into the environment.  

The other technology used is Ultraviolet light (UV-C), which is a well-established method of disinfection that has been used for decades to prevent the spread of viruses and bacteria. It can clean air, surfaces, objects and water by breaking down the DNA or RNA (ribonucleic acid) of micro-organisms, rendering them harmless. All bacteria and viruses tested to date (many hundreds over the years, including various coronaviruses) respond to UV-C cleaning.

The device is designed to clean the air during day-to-day activities while people are present. Ventilators pull the air from the room inside the device which then filters and cleans it.

The project is not expected to report back until the first half of next year.

Buildings resilient to infection

A recent report by the Royal Academy of Engineering and the National Engineering Policy Centre (NEPC) has shown that good ventilation inside public building is essential to reducing the risk of Covid-19 and other infections.
Patrick Vallance, the government’s chief scientific adviser, commissioned the report to review how we design, manage, and operate buildings and how we can make infrastructure more resilient to infection. The initial report, ‘Infection Resilient Environments: Buildings that keep us healthy and safe’, highlights the importance of good indoor air quality (IAQ) for reducing transmission of Covid and other infectious diseases.

The report calls for clear, consistent communication and advice on ventilation from government and professional bodies 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.

The report also warns that there is an urgent need to plug skills and knowledge gaps and put in place the training, re-skilling and recruitment needed to fill them. Even in sectors such as hospitals have levels of skill and competence that vary.     

Professor Peter Guthrie OBE FREng, Vice President of the Royal Academy of Engineering and Chair of the NEPC infection resilient environments working group, says: “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. We must also integrate this with thinking on infection control into our approach to Net Zero, to prevent inadvertently hard-wiring a susceptibility to infection and other health risks into our building stock and management practices.”

Dr Hywel Davies, technical director at the Chartered Institution of Building Services Engineers, says:“Clear communication on ventilation is essential – we need to support owners and operators with clear and simple guidance, emphasising the importance of improving ventilation while maintaining wider good practice on infection control.

“Our aim should be to enable everyone who has responsibility for managing buildings or transport to understand how to respond in a practical and timely manner, and to establish an appropriate balance of measures to manage infection risks alongside thermal comfort, air quality and energy concerns.”

Schools in Wales

The Welsh Government is investing £3.31 million to improve ventilation in schools, colleges and universities in Wales.

The funding will be used to improve ventilation in education settings such as school classrooms, colleges and lecture halls in a move to reduce the risk of spreading COVID-19 and create safer learning environments for pupils, students and staff.  

CO2 monitors are also being rolled out in educational settings across Wales. The new CO2 monitors which include sensors will notify teachers and lecturers when CO2 levels rise, so they can identify where ventilation needs to be improved. This will help maintain comfortable temperatures for learners and staff during colder periods, reduce heat loss and save on energy costs.

The Welsh Government has also recently announced that £50m will be available to schools via local authorities to help schools carry out capital repair and improvement work, with a focus on health and safety measures, such as improving ventilation.

Improving indoor air quality

The Building Engineering Services Association (BESA) and its affiliate member Mitsubishi Electric have created a ‘Beginners Guide’ to improving Indoor Air Quality (IAQ), which has gained the support of one of the UK’s most high-profile child health campaigners, Rosamund Adoo-Kissi-Debrah.

The ‘Beginner’s Guide to Indoor Air Quality’ offers advice and guidance to a broad audience, including school leadership teams, given the importance of good air quality in schools.

The digital publication is designed to give a comprehensive, but non-technical introduction to the subject and can be downloaded for free here.

The Beginner’s Guide will also be of interest to engineers and specialist firms involved in designing, commissioning, and maintaining indoor environments because it provides a useful overview of the main topic areas. It would work as a starting point for anyone looking to set up a strategy for tackling the poor IAQ that is having a detrimental impact on thousands of UK buildings and their occupants.

With an introduction from Kissi-Debrah, the Guide, which includes a wealth of information provided by BESA’s Health & Wellbeing in Buildings group, explains how the ventilation and building services industry is able to turn buildings into ‘safe havens’ to protect occupants – particularly children who face the greatest risks – from the worst impacts of contaminated air.

“This guide is an invaluable non-technical introduction to the issue of IAQ and explains how we can make our own indoor environments safer and healthier for us and our children,” said Kissi-Debrah, who is also honorary president of the BESA group.

The guide is designed as a jumping off point from which anyone affected by the health and wellbeing implications of poor IAQ can engage with specialists to start addressing their problems.

It explains how good ventilation and air filtration along with accurate measuring and monitoring of particulate matter are the keys to an effective IAQ strategy. It also includes information about the main sources of air pollution and the contaminants that affect indoor spaces and explains why IAQ is often many times more damaging to human health than outdoor pollution.

Outdoor air quality

Natural ventilation by opening windows can sometimes lead to other problems, if the air quality outside a school is poor.

Research from City Hall has revealed that more than 3.1 million children in England are situated in schools in areas with toxic levels of air pollution. The research found that children in London are four times as likely to go to a school where air pollution exceeds WHO limits compared to the rest of England – but still a quarter of schools in the rest of England are exposed to similarly high levels.

There are some measures that schools can put in place to improve the air quality around their schools, such as creating no car zones, anti idling campaigns and promoting active travel.

To stop the outdoor air pollution from coming into a school, air purifiers can help.

Christopher Hatton Primary School and Netley Primary School & Centre for Autism have participated in real world trials with Blueair following the Mayor of London’s School Air Quality Audit Programme. More than three years on they continue to use air purifiers, owing a reduction in absenteeism and sick leave to the units.

Alan Murphy, Air Quality Leader at Netley commented: “Our teachers are clearly appreciating the importance of clean air and the role the Blueair units play in helping to achieve it. Polluted air is shown to adversely impact on health and wellbeing, especially for children. It is a major focus for Netley due to HS2 construction and the congested roads around our school. Monitoring has shown very high levels of air pollution inside many classrooms at Netley. The air purifiers installed have dramatically improved the air quality internally.”