Determining thermal comfort in built environment using computational fluid dynamics simulations

In this thesis, three-dimensional time-dependent Thermal Comfort (TC) conditions in an occupied room is investigated and determined. The room is considered with furniture of varying materials (i.e. steel, wood, etc.) and under incident solar radiation. A Computational Fluid Dynamics (CFD) method, FloEFD software was used to enable designers to perform accurate and fast analysis. This computational tool allows detailed 3D visualizations and inclusion of geometrical details of the diffusers of the HVAC system. To determine the required TC conditions such as the I) air distribution, II) indoor temperature profiles, III) humidity, and IV) the mean radiant temperature profiles, the CFD method is used. This work is significantly different from the earlier works as it includes the spectral surface emissivity of the existing materials in the room and the spectral transmissivity of windows' glasses. In the analyses, both conduction and spectral radiation, which have led to calculate more accurate and detailed TC conditions, are considered. The mentioned analyses reach agreement with the experimental data obtained in the room. The visualization of four parameters is done for different scenarios by evaluation of the change of the window properties inside the room and the HVAC diffuser. Subsequently, these values were interpreted as PMV and PPD for thermal comfort with Fanger method, depending on human clothing and metabolic rate. The completion of the comparison scenarios during the sunshine time of 8 hours allowed considering the warm-up period of the materials in the room. Therefore, it has come to the conclusion that the long-wave radiation of heated materials can affect TC, not just direct radiation of sun. With the new diffuser scenario, the occupant is locally, positively influenced by the thermal comfort due to blowing the incoming air directly into the seating area. However, with this secondary diffuser, it has been found that the thermal comfort decreases more rapidly in the comfort zone during the 8 hours. The reason for this is that the primary diffuser in which the comparison is made delayed the heating of the material by blowing directly into the glass and the wall. The findings of this research can be used to evaluate TC in big glass façade cladding spaces.