Dominique Hes, M.AIRAH

City of Melbourne
BREATH – Rapid retrofit research project: Getting back to work safely

To reduce COVID-19 transmission, building managers have been told to maximise ventilation, open windows, flush air through the building, and improve air filtration. These can all increase energy consumption – impacting NABERS ratings, costing more, and compromising comfort. This research tested the effectiveness of the first two recommendations (maximise ventilation and open windows) at reducing transmission and their impact on energy use, and then looked at some alternatives. This was a pilot study conducted over three months, in an existing building, on a limited budget. The results are therefore indicative.

We called the project BREATH (Building Retrofit for Efficiency, Air Quality, Thermal Comfort and Health) with the aim of looking at energy and transmission reduction to inform the retrofit of buildings to meet their zero carbon commitments while providing healthier places to work.

This rapid retrofit program investigated how office building ventilation systems could be adapted to improve air quality whilst maintaining high levels of energy efficiency. The project measured the impacts of three ventilation interventions: the impact of opening windows combined with standard HVAC operations; the addition of in-ceiling air cleaners; and bringing air delivery down to the floor-level with column-based displacement ventilation.

This program is the first to test these interventions – not only for their impact on COVID transmission (Omicron-B1), but also the cost and energy use change. The BREATH project found that all three interventions could reduce COVID-19 transmission in the workplace. Displacement ventilation improved on the base case by 83 per cent and was better than both open windows and in-ceiling air cleaners by 50 per cent. Displacement ventilation was also estimated to reduce energy consumption by 10–20 per cent depending on external conditions.

This keynote presentation on the BREATH project demonstrates the value of collaboration between businesses, government, and academia; and is driven by our shared commitment to taking meaningful action on climate change for the health and benefit of our community.

About Dominique Hes:
Dominique has been part of the AIRAH community for over 10 years. She is the Zero Carbon Building Lead at the City of Melbourne and Chair of the board of Greenfleet. She is an award-winning educator and writer with more than 25 years’ experience at universities, professional organisations, and communities. With degrees in botany, engineering, architecture, and a certificate in governance, Dominique brings an interdisciplinary approach to all her work.

Her question in this work was can we provide healthier indoor air, reduce energy consumption and support the retrofit commercial buildings.