Wind characteristics on building surfaces are used to evaluate natural ventilation of a building. As a type of building component, external shading louvers are applied in hot climatic regions to block solar radiation and provide better visual environments. The structure of external louvers can affect wind-induced characteristics, such as convective heat transfer coefficient, wind pressure and pollutant dispersion around building envelopes. This paper aims to analyze the potential ventilation capacity of a multi-storey building with shading louvers, based on wind pressure coefficient by the numerical method. A reference case was established and a previous study was applied to validate the numerical results. The rotation angle of horizontal louvers is taken from 0° to 75° in the simulation cases. The results show that average wind pressure has the greatest reduction for all floors when rotation angle turns from 60° to 75°. Ventilation openings on the stagnation zone contribute to higher ventilation rates for the windward facade with louvers. The analysis, based on multi-floor and multi-row buildings under shaded conditions, will provide a greater perspective for engineers to make optimal natural ventilation routes in multi-storey buildings with external shading louvers.

This paper presents a comparative study of the cross-flow regenerative heat and mass exchanger (HMX) and the conventional cross-flow HMX for indirect evaporative cooling (IEC) with numerical methods. The objective of this study is mainly to clarify the applicability of the two HMXs. The numerical model was built and validated by existing experimental data. The difference in heat and mass transfer between the two HMXs was revealed by analyzing the change of the temperature and moisture content of the air, and the influence of the main operating parameters on the cooling performance of the HMXs was analyzed. In the typical operating conditions, when the HMXs are used alone, the cooling performance of the regenerative HMX is better than that of the conventional HMX under low supply air flow rate. When the HMXs are used in the multistage evaporative cooling systems with high supply air flow rate, the conventional HMX is more suitable as the first stage of the system to pre-cool the supply air, while the regenerative HMX is more suitable as the second stage to re-cool the supply air.