New research from the City of Melbourne has found that simple changes to ventilation systems can significantly decrease the transmission of COVID-19 and reduce energy consumption in office buildings.

The BREATH pilot tested and evaluated three different ventilation systems in a vacant CBD building over three months: displacement ventilation air conditioning, in-ceiling air filters and natural airflow through open windows. 

Key findings include:

• All three ventilation systems reduced the potential transmission of airborne viruses when compared to standard ceiling-based air conditioning, improving safety for office workers. 
• Displacement ventilation air conditioning – which supplies air from floor level – was the most effective and energy efficient system tested, reducing COVID-19 transmission by 83%, while also reducing energy consumption by 20%. 
• Displacement ventilation is the most expensive to install, but there are no additional ongoing maintenance costs. 
• In-ceiling air filters reduced virus transmission by 49% but resulted in a minor increase in energy consumption. 
• Opening windows reduced virus transmission by 53% , but increased energy use by up to 20% with seasonal temperature variations.

The BREATH project was led by City of Melbourne and delivered in partnership with Cbus Property, University of Melbourne, AG Coombs, SEED Engineering and Westaflex, with peer review by AURECON.  

More information here