Air Ventilation project: Where are we now?
Busworld Foundation’s Adapted Air Ventilation in Buses program has come to first conclusions on air ventilation in coaches.
The simulations in “the bus case” are running as we speak. The main difference between the coach-case and the bus-case is how many times, and for how long, the doors are opening; you will understand that the air flows in a bus, with door openings every 3 to 4 minutes, for about 15 to 30 seconds, are very different from coach trips where doors can remain closed for over one hours or more.
Variables are the positioning of the air vents, positioning of the extraction vents, flow rate, etc. The final results of each simulation are translated into a graphical estimation of the cross infection risk for the passengers at each seat in the bus or coach.
Remarkable finding in the coach case is that -depending on the position of the air vents and air exit vents- only about 10% of the fresh air blown into a coach, actually find its way to the extraction vents; and that higher flow rate performs significantly better but not due to increased extraction of particles but due to stronger recirculation and higher deposition rate, as is shown I the figures below.
The goal of the program is to describe air flows in buses and coaches, and how they can be manipulated via adequate HVAC systems, so the risk of contamination by viruses can be reduced to almost zero. Based on the findings, propositions to the bus manufacturing industry and to the HVAC suppliers for the bus industry are going to be made concerning the placement of the air vents and extraction vents, concerning the volume of air that is blown into the vehicle (the flow rate), concerning air treatment technologies and tools and concerning cleaning strategies and tools.
This research program on the air flows is done in a partnership with the University of Ghent in Belgium. In addition to this study on the air flows, additional chapters will be added on air purification technics such as photocatalysis, ionisation, use of UV light, etc… in collaboration with the University of Hasselt (Belgium).
Partners from the Bus & Coach Industry are VDL, Yutong, Ashok Leyland, Siemens, Denso, Flettner, Sanz Clima, Ellamp, De Lijn (the Flemish public transport agency), GPN – the Global Passenger Network, and the Flemish, Belgian and Swedisch federation for bus & coach operators. Companies, institutions, federations…
Interested in being a partner? Contact us!
Each partner in the consortium has a chair in the steering committee, deciding on research and dissemination of the results.