Experimental and simulation analysis of different natural ventilation scenarios and their relation with IAQ in office buildings

Following the pandemic of Covid-19, the scientific interest in ventilation rate of buildings, and especially in spaces with high occupancy, has increased. The creation of a healthy and acceptable internal environment, especially at workplaces is considered necessary, both to deal with the sick building syndrome, or the spread of various diseases, as well as to improve the comfort of employees. In the proposed work, the experimental investigation of the indoor environment in naturally ventilated office buildings, located in Kozani, Western Macedonia, Greece, is presented; the investigation took place during the pandemic period of Covid-19. Measurements include thermal comfort parameters as well as Indoor Air Quality (IAQ) ones. As concern the ventilation of the buildings, the air exchange rates were determined according to the tracer gas decay and equilibrium analysis methods, using CO2 as tracer gas; simulation analysis using appropriate computational approaches (CONTAM) was also applied. Different scenarios of ventilation, like natural ventilation with open or closed windows and mechanical ventilation, were applied; ventilation rates were assessed, as well as the concentration of chemical compounds like CO2. The elaboration of results leads to the formulation of a daily practice concerning the opening of the windows or the operation of the mechanical ventilation system, in order to optimize IAQ, while energy consumption would also be potentially decreased. The proposed approach, combining experimental and computational tools, can be further elaborated, towards the formulation of an integrated methodology, contributing to healthier and more comfortable indoor environment, while energy aspects can also be considered.