The aim of this study is to investigate the effects of louver opening configuration and relative humidity for natural ventilation of an isolated building. This study contains four different relative humidity settings (20%, 40%, 60% and 80%) with five different opening configurations windward and leeward walls. A middle-middle louver opening configuration was first studied to validate the result with (Kosutova et al., 2019). Each louver opening configuration was simulated using Computational Fluid Dynamics (CFD) with RNG k-epsilon turbulence model with enhanced wall treatment. Grid sensitivity analysis and model validation was conducted using previous study to ensure accuracy on findings. From initial analysis, comparison shows good agreement as the results are similar. From the simulation cases, increasing relative humidity for various louver opening configuration does affects the overall temperature distribution in each wall. From the results, the dimensionless flow rate (DFR) in Top-Top Louver opening configuration shows the greatest DFR. This statement have an agreement with recent researches which indicates the Top-Top louver opening configurations has an highest flow rate throughout the building. Furthermore, according to the velocity contour, the top-top and top-bottom opening configurations have a greater air exchange rate at the top of the building, while the bottom-bottom and bottom-top opening configurations have a higher air exchange rate at the bottom of the building. Therefore, this study concludes that opening position with louver plays an important role on the internal airflow and DFR in building natural ventilation.
Buildings consume about 40% of global energy, 25% of global water, 40% of global resources, and emit roughly 1/3 of global greenhouse gas (GHG) emissions, according to the United Nations Environment Programme (UNEP). (UNEP, 2021). When comparing natural ventilated and air-conditioned buildings, the carbon emitted and energy usage for air-conditioned buildings are 66% and 67% greater, respectively. As a result, the UNEP encourages the construction industry to combine new designs, technical innovation, and governmental policy to improve energy efficiency of a buildings (UNEP, 2021). Natural Ventilation has the potential and is a viable approach to attain thermal comfort without leading to climate change.
The objective of this study is to investigate the effect of various louvers opening configurations with different relative humidity on the velocity, pressure contours, and dimensionless flow rate (DFR).
The general isolated reference model was based on the model by Kosutova (Kosutova et al., 2019). The reference model is 150 mm × 150 mm × 150 mm (L × W × H). The reference model includes two louver openings, one on the windward facade and the other on the leeward facade. The dimensions of the opening are 70 mm × 40 mm (W × H). The louvers have a 10 mm gap between louvers, the slat angle of the louvers is 15°, while the thickness of the louver is 0.75 mm. The total thickness of the reference model is 10 mm and the wall porosity of the building is 12.5 %.
Faculty of Engineering, Built Environment and Information Technology
