German research on the dispersal of aerosols in concert halls

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This study by the Fraunhofer Heinrich Hertz Institute measures Aerosol and CO2 at a concert hall in Dortmund, Germany called Konzerthaus Dortmund. It provides facts on the risks of a coronavirus infection during visits to concert halls and theatres. This is important groundwork for preparing to reopen live music and events. 

On behalf of Konzerthaus Dortmund; Fraunhofer Heinrich Institute Goslar and the measurement specialists ParteQ, investigated the spatial dispersion of aerosols and CO2 in the concert hall. The study was conducted in collaboration with the German Environment Agency (Umweltbundesamt) and hygiene experts.

It is the first published study to provide experimental data for evaluating the coronavirus infection risk during concert hall visits with extensive measurements being taken in the Konzerthaus Dortmund auditorium and foyers in November 2020.

The study shows that the risk of transmission of infectious agents by aerosol transmission can almost be excluded, especially in the auditorium. Utilisation of the existing central ventilation system and the wearing of facemasks greatly reduces aerosol and CO2 pollution, to the point that full occupancy of the concert hall would theoretically be conceivable.

However, after taking into account access routes and foyers, a checkerboard auditorium layout is recommended, i. e. 50 % of auditorium capacity. In addition to the specific results for a visit to Konzerthaus Dortmund, the study can also be used to make similar statements for other similarly sized concert halls and theatres.

The following can be summarised for Konzerthaus Dortmund based upon the results of the study:

  • With a mask, and with a sufficient supply of fresh air via the existing ventilation and air conditioning system, there was practically no influence of test aerosols on any of the neighbouring places from an emitting test person during the tests.
  • The large room volume already ensures a strong dilution of contaminated aerosols, and due to the supply and extraction air operation of the ventilation system without recirculation function, aerosols are effectively removed in all areas and cannot accumulate.
  • Without a mask, the seat directly in front should be kept free. With the remaining neighbouring seats, infection is very unlikely. A checkerboard seating arrangement of the auditorium is recommended in any case.
  • Greater number of people in the auditorium does not disturb the upwards air flow, but rather promotes it through additional thermal effects.
  • Wearing masks is always necessary in corridors, in break areas, and in the foyers, as the ventilation system works differently here than in the auditorium (where air escapes through the ceiling) and where close contact cannot be ruled out. During breaks, all doors to the auditorium should remain open to allow for additional cross- flow ventilation.
  • The concert hall cannot trigger a superspreading event with the existing ventilation in place (with a complete air exchange with fresh, outside air every 20 minutes).
  • CO2 measurements during operation can help to better assess the dispersion of air- borne particles in the auditorium.

You can read more on the study here

This research could be very important on government decision-making when it comes to the re-opening of halls and theatres, which, of course, is of crucial importance to our industry.