Smittspridning i ventilerad inomhusmiljö

Sammanfattning: The transmission of airborne aerosols in a ventilated indoor environment has become highly relevant since the Covid-19 outbreak. Initially, Covid-19 was only assumed to be spread via droplet and contact infection, but research and known outbreaks show that airborne transmission via aerosols occurs. Modern humans spend a large part of their life indoors. Understanding and calculating how virus-carrying aerosols behave in an indoor environment is necessary to be able to design ventilation systems in the most efficient way to limit the spread of infection. The thesis examines whether it is possible to link measured particle quantities to a risk for becoming infected via airborne aerosols in an indoor environment. Since particle measurements are easily conducted, such a correlation is useful. In addition, this thesis also aims to determine how the risk of becoming infected with Covid-19 varies with different ventilation solutions. The study is limited to analysing the risk of infection in an office environment; therefore, all calculations are based on a theoretical situation with an infectious person in a conference room. Applying it to reality, measurement data is used from a conference room where displacement ventilation has been installed. The primary point of focus is on which aspects affect the number of particles that reach a person and how viruses spread in a ventilated indoor environment. The workflow is presented in a chronological order where each method is presented, evaluated and it is decided whether they can be used to achieve the purpose of the thesis. To determine a correlation between the number of particles and the risk of becoming infected, a ventilation index needs to be used. It is therefore concluded that it is not possible to determine a direct connection to the number of particles with the data available in this thesis. Instead, the ventilation system's ability to remove particles from the occupancy zone is crucial for the risk assessment. More research on Covid-19 is needed to be able to perform risk calculations with good precision. Implementing measures in the ventilation system to increase the ventilation index reduces the risk of becoming infected.