Ventilation on Our Buses (COVID-19 Service Updates)
Every AC Transit bus is doing much more than safely getting you to your destination; our buses are also filtering the onboard air.
By keeping all windows closed, new air filters along with the HVAC system, create a powerful air vacuum forcing old onboard air out and circulating fresh-filtered air every minute and 12 seconds.
It’s cleaner air for everyone on board.
How do we maintain onboard air quality?
The closed windows, in conjunction with the onboard HVAC system, create positive pressure that pulls fresh air inside the bus and forces old air outside the bus.
While it is true that opening windows can bring fresh air inside the bus, doing so also creates onboard turbulence that either slows or prevents air from entering the HVAC system. Onboard ventilation cannot then be properly maintained because the air vacuum of the HVAC system is dramatically disrupted, which both reduces filtered air and its quality.
How can we optimize safety onboard for everyone?
In response to COVID-19 health orders, safety experts conducted a series of tests to examine the flow of air onboard our buses. Ventilation conditions were tested with windows opened and closed. The test results unequivocally concluded that any open window will disrupt the onboard air quality. By keeping bus windows closed with HVAC systems on, safety is optimized.
If you have any concerns regarding ventilation on our buses, please call Customer Service at 510-891-4777 or submit input to actransit.org.