Impact assessment of natural ventilation on thermal comfort levels in sustainable residential buildings

In the present paper the impact of natural cross-ventilation on thermal comfort levels in sustainable residential buildings is evaluated. A sustainable dwelling is designed in Crete and various scenarios of different combinations of open windows and doors in the ground floor, the first floor and between the floors are tested to determine the final scenarios with the best possible airflow movement. Three scenarios with open windows and doors in the ground floor and six (6) between the floors (9 total scenarios) are chosen to be the final scenarios where the impact assessment of natural ventilation on thermal comfort levels is performed. Computational Fluid Dynamics (CFD) simulations with the 3D steady Reynolds-averaged Navier-Stokes (RANS) approach and the Shear Stress Transport (SST) k-ω turbulence model are used for the study of thermal comfort levels, along with the Predicted Mean Vote (PMV) index. The Scenarios are tested for a typical summer day for four different hours and environmental conditions. The designed building is treated as a stand alone in all the simulations and it is not an existing construction. From the analysis of the results we observe that natural ventilation, in many cases, is an effective way to achieve indoor thermal comfort. In many Scenarios the high values of PMV from the Base Scenario (no windows or doors open) are decreased and in a few cases the values fall into the cold zone of comfort. The layout of the floors also affects the airflow movement in addition with the openings and the environmental conditions and can be used accordingly. According to the author’s knowledge in the field of investigating natural ventilation via numerical approach simulation the present study is an original attempt to examine a more elaborate building architectural design and analyse performance in a dynamic way according to variable weather conditions.