Microenvironment around People

Student thesis: Master thesis

  • Jan Zajas
  • Michal Litewnicki
Nowadays, a lot of attention is drawn to the subject of airborne diseases. Various measures
can be taken in order to prevent the cross infection between people in closed spaces. One of
them can be choosing an air distribution system that could work as a way to remove
contaminants exhaled by one person before they can affect other people in the room. Most
common distribution systems are: mixing and displacement ventilation.
This report focuses on characterizing the cross infection in a room with air distributed by
diffuse ceiling inlet what creates fully mixed conditions in the room. Several experiments are
carried out to evaluate how this ventilation system works in regards of cross infection.
First part of measurements covers experiments with one thermal manikin. The exhalation
jet is examined in order to provide a thorough description of its behavior and to create a
mathematical description of velocity and concentration distribution in it.
Second part covers measurements with use of two manikins. It is checked how one exhaling
manikin can influence another one in terms of personal exposure.
CFD simulation are also carried out as a way to supplement the results and serve as a
comparison for experiments.
By all these measures the subject of cross infection in a mixing ventilated room can be fully
described. Moreover, results are compared with previous research that focused on another
air distribution system: displacement ventilation. This comparison can lead to conclusions on
which system should be used in spaces where there is a need to diminish the effect of cross
Publication date28 Jun 2010
Number of pages90
Publishing institutionAalborg Universitet
ID: 32975379