MAN Truck & Bus
We assess the risk to be very low
The health of passengers and drivers takes top priority when operating urban buses, inter-city buses and coaches. This applies all the more in the age of the corona virus. In addition to the generally applicable distancing and hygiene regulations, increased attention is being paid to the correct use of air conditioning systems. MAN Truck & Bus gives bus operators and drivers important recommendations for action.
Heinz Kiess
is a bus product marketing manager at MAN Truck & Bus. He explains the aspects to which bus operators and drivers should pay particular attention to minimise the risk of infection in the passenger compartment during the corona phase.
Mr Kiess, what can be done to minimise the risk of being infected with the corona virus?
KIESS Drivers and bus operators should consider various measures to reduce the potential distribution of viruses in the passenger compartment via the bus air-conditioning system. The air conditioning system should firstly only be used in fresh air mode if possible and without the recirculation function. The system should also not be deactivated manually using a button, as this only switches off the air conditioning compressor but not the fan. It is also best not to manually reduce the fan speed. This avoids reducing the amount of fresh air in the passenger compartment. In the case of buses with service sets, we recommend closing them before departure. This can further increase your passengers' sense of security. The reason is that passengers are not exposed to a direct air stream and the air only comes from the ventilation openings in the roof duct. The pollen filters in the rooftop system and the front box should be replaced regularly and at shorter intervals to increase air purity.
How does air conditioning in buses generally work?
KIESS The target temperature in the passenger compartment is controlled by heating elements, which are located in the passenger compartment both under the seats and on the side walls. The front box and rooftop air conditioning system also contribute to achieving the desired temperature. Depending on the ambient conditions, the ratio of fresh and recirculated air is controlled by the so-called passenger compartment regulator. This filters the air via pollen filters that are installed in series, some with active charcoal sets. The exhaust air is then discharged via separate ducts. These ducts permanently remove the stale air from the interior during active ventilation, thus ensuring uninterrupted air circulation.
The stale air in the bus is discharged via separate ducts and, with active ventilation, is permanently removed from the interior. This ensures uninterrupted air circulation.
How great is the risk of infection via an air conditioning system?
KIESS In theory, potential infection with the corona virus via the air conditioning in a bus cannot be excluded – but we assess this risk to be very low. Other factors, in particular failure to comply with the generally applicable rules on distancing and hygiene, present a far greater risk of infection. That is why the safety measures specified internationally by countries and recommended regionally by federal states should also be observed in buses. Bus drivers and bus operators should also ensure that handrails and handholds in particular are regularly disinfected. We also consider special hygiene measures and disinfectants at the entrances to be very useful.
