Der Nahverkehr - February 2021

Indoor air disinfection in local transport

Air circulation in buses and trains

In general, ventilation and air conditioning in local transport, such as buses and trains, are centrally controlled. This also means that, apart from the Alass nozzles on the seats, all air currents are predetermined. As a rule, passengers have no direct influence on this. If the driver or sensors change these ventilation or air conditioning settings, this has a direct influence on all passengers. this is exactly where one of the central problems lies, comparable to integrated cooling systems in buildings. In the case of infected persons on board, pathogenic agents, here aerosols, are distributed to practically all passengers using a central control system. The same problem is understood when disinfection modules, regardless of the technology, are simply retrofitted in existing ventilation systems in buses and trains, even if this initially seems to be a sensible option.

Much better protection against infectious pathogens can be achieved with modules in which the ventilation and air conditioning system as well as the room air disinfection have separate circuits. This protection can be optimized even further by dividing this second air circuit over the passenger area again and thus creating separate laminar air circuits that cannot mix directly during the journey.The more clearly these circuits are separated, the better the protection. So it would be ideal to be able to mix the infectious air directly. The more clearly these cycles are separated, the better the protection. It would therefore be ideal to attack and eliminate the infectious air directly in the passenger.

You can download the full report as a PDF:

PDF: Indoor air disinfection in transport