Simple changes to ventilation systems can significantly decrease the transmission of COVID-19 and reduce energy consumption in office buildings, new research has found.
The findings are part of a pilot research project led by the City of Melbourne in partnership with the University of Melbourne and Cbus Property.
The BREATH project tested and evaluated three different ventilation systems in a vacant CBD building over three months:
The systems tested were displacement ventilation air conditioning, in-ceiling air filters and natural airflow through open windows.
The project found that all three ventilation systems reduced the potential transmission of airborne viruses when compared to mixed ventilation, improving safety for office workers.
The most effective and energy efficient system tested was displacement ventilation air conditioning which supplies air from floor level.
This system reduced COVID-19 transmission by 83 per cent while also reducing energy consumption by 20 per cent.
However, displacement ventilation is the most expensive to install but there are no ongoing maintenance costs.
In-ceiling air filters reduced virus transmission by 49 per cent but resulted in a mainor increase in energy consumption.
Opening windows reduced virus transmission by 53 per cent, but increased energy use by up to 20 per cent with seasonal temperature variations.
Opening windows is not available to all office buildings and is not a viable solution due to Melbourne’s climate.
University of Melbourne head of mechanical engineering Professor Jason Monty said the collaboration between local government, industry and academics is a world-first.
"BREATH has given us the knowledge to predict the best type of retrofit to simultaneously reduce carbon footprint and infectious disease transmission,” he said.
“Since the majority of city energy cost goes to ventilation of our buildings, the outcomes from BREATH will improve our ability to reach net zero carbon faster.”
University of Melbourne vice-president (Strategy and Culture) Dr Julie Wells said the project shows how the University tackles problems of local and global significance with its partners.
"This collaborative pilot demonstrates the positive impact that the University of Melbourne's research can have on human health and energy consumption," Dr Wells said.
"The findings provide a great basis for building owners to proceed with an informed approach to ventilation options. We look forward to more great results arising from partnership projects developed with the City of Melbourne and industry partners."
Lord Mayor Sally Capp said bringing people back to the city safely remains a key priority.
"The research findings are publicly available online and free for any organisation to access. We encourage building owners, tenants and partners to take them on board, and to help us create more healthy and sustainable workspaces in the CBD,” she said.
City of Melbourne Sustainable Building portfolio lead Councillor Elizabeth Doidge said the research can benefit businesses helping to reduce their environmental footprint and operating costs."
“We’re committed to working closely with our partners and will continue to support the creation of buildings that are more sustainable for our environment and for the future of our city, its businesses and its people,” she said.
The BREATH project was delivered with industry partners Cbus Property, AG Coombs, SEED Engineering and Westaflex, with peer review by AURECON.