Ventilation systems on trial

Since last spring, theatres and their technical directors have been occupied with a new set of tasks revolving around protection against infection, installing appropriate hygiene concepts, and preventing the spread of Covid 19. In parallel with organizing the measures necessary to comply with in-house regulations, theatre directors are looking into additional strategies to enable them to reopen their doors. In this regard, technical installations are key.

Following recent public debate, increasing attention is being paid to ventilation systems in theatres and concert halls. If functioning effectively, these air-conditioning systems offer the best possible protection against infection with Covid 19. Effective regulation and channelling of fresh-air inflow away from used air masses are key parameters that theatres must check when taking stock of their houses. Theatre ventilation systems, mostly built to comply with VDI 6022 hygiene requirements, now need to be double-checked in the light of ensuring optimum pandemic protection. For this reason, we at the DTHG launched this research project together with the NRW Ministry of Culture and Science. 

The project’s objectives
Our goal is to inspect operational ventilation systems to identify any trouble spots and work out a catalogue of measures for improving the technologies currently in use. In addition, we aim to provide accessible, user-friendly information:
Assessing the current technical and hygiene-related condition of ventilation systems
Providing a basis for planning necessary improvements
Conveying recommendations by a team of experts, or suggestions for improvements
Offering a transparent and accessible system of assessment to calibrate the performance of ventilation systems in terms of their anti-pandemic effectiveness.

Several parameters must be factored in to ensure the scientific reliability of our findings: spatial volume, system capacity, rate of air exchange, proportion of circulation, and various air current directions, to name just a few. First, we needed to find out what the current systems are capable of under pandemic conditions. NRW Minister of Culture and Science Isabell Pfeiffer-Poensgens wrote to 27 theatres and concert halls in North Rhine Westphalia to inform their directors of the project, explain our cooperation, and seek their participation.

It soon became clear to the team of experts around ventilation expert Prof. Dr. Rüdiger Külpmann that we should not limit our inquiry to the public-accessed areas of theatres but also include rehearsal spaces and other areas where work is conducted, at least in terms of data collection, so as ​not to close the door on further investigations at the outset. The final goal is to award certificates to venues that have been checked and approved so that the public can attend with confidence. Complementary studies such as the Fraunhofer Institute’s inspection of the Dortmund concert hall regarding the possible spread of aerosols in the auditorium were incorporated into the inquiry in addition to the various theatre parameters. To this end, special software was designed to allow participants to simply enter their data in the corresponding fields. 

It took eight weeks of the three-month project to perfect a program that could depict every publicly used theatre space using various models: From recording the ventilation systems’ parameters to calculating the maximum permissible and possible size of audience and finding options for useful technical improvements or just extending the settings, these have produced many aids to decisionmaking concerning reopening arts venues. When the project in NRW is completed, the DTHG hopes to make it possible for all German theatres to have their ventilation systems inspected by a team of experts. Different models are already being tried out, and funding options discussed with local governments. A model with special conditions for DTHG members is also being included in the planning, as well as the option of theatres contacting the DTHG headquarters directly.