This concerns distribution in, for example, public transport and in nursing homes. The results were published in the scientific journal The Lancet Respiratory Medicine. Konvekta and MAN advice to clean airconditioning systems regularly and replace the filters.
In the UvA research healthy people were asked to speak and cough after which the dispersion of small droplets (aerosols) was analyzed with laser light. The drops floated to the ground for minutes. After five minutes, half was still in the air. In the same test in a well-ventilated area half of the droplets disappeared from the air in 2.5 minutes. If a door or window was open in the room, it was halved within thirty seconds.
According to the researchers, keeping sufficient distance in public transport is not enough to limit the risks. Also app’s to determine whether people were in the vicinity of an infected person are therefore not sufficient. The focus should be on good ventilation, the researchers conclude.
Konvekta AG, manufacturer of air conditioning systems received the last months many questions and concerns from vehicle operators and manufacturers. The main question is: How do coronaviruses behave in conjunction with air conditioning systems? The company states the German Robert Koch Institute believes ninety percent of transmissions occur via droplet infection (coughing and sneezing) and nine percent through contact with contaminated surfaces. Higher fresh air content by regular ventilation therefore reduces the risk of infection as Konvekta says. “Ventilation also improves interior climatic conditions and, by increasing air humidity, prevents dryness in the mucous membranes in the nose and mouth, which in turn gives better protection against pathogens.”
Konvekta emphasizes air conditioning systems require regular servicing. This involves inspecting the system for contamination and changing filters or, in the case of metal filters, cleaning them. If the servicing intervals have been adhered to, no extra service is now required. In fact, Konvekta says the air improves because it can only enter a vehicle’s interior by passing through sensitive filter technology. The number of germs measured at outlets were lower than those at air intakes.
Also MAN Truck & Bus is giving drivers and operators some important recommendations. Heinz Kiess, Head of Product Marketing Bus at MAN Truck & Bus: “Firstly, the air-conditioning system should only be used in fresh-air mode – if possible – and without recirculation. Also, the system should not be manually deactivated using the switch, as this only shuts off the refrigerant compressor and not the blower. To avoid reducing the amount of fresh air in the passenger area, the blower speed should also not be manually decreased. To increase air purity, the interior air filters in the roof-mounted air-conditioning system and the front box should also be replaced at regular, short intervals. Further more, the used air is discharged through separate ducts. With active ventilation, the used air is permanently purged from the vehicle interior through these ducts, which guarantees seamless air circulation. In addition, bus drivers and operators should ensure that grab handles and poles in particular are regularly disinfected. For our new generation of city buses, we will shortly be in a position to offer a protective screen for the driver’s workplace as special equipment installed at the plant – and as a retrofitted solution through After Sales.”