Quantifying natural cross-ventilation flow of a two-layered model used for terraced houses in tropical zones by particle image velocimetry

Abstract

Wind-induced natural ventilation is a sustainable approach for improving the indoor thermal comfort, air quality, and energy consumption. Although numerous ventilation studies have addressed generic ventilation models, the cross-ventilation flow of a multilayered model (widely ingrained in a tropical climate zone such as Malaysia as a typical terraced house with a deep-plan layout) has not been studied well. Therefore, this study aims to investigate the flow patterns inside a simplified two-layered model separated by a second floor at the middle height with an opening using wind tunnel experiments. Two cases are considered based on the positions of the inlet and outlet openings on each floor. Two velocity components are measured using particle image velocimetry (PIV) and hot-wire anemometry (HWA). This study provides high-quality experimental datasets, which enables us to understand turbulent characteristics of indoor airflow, obtained using PIV and HWA for a generic two-layered cross-ventilation model. In addition, the results show that the ventilation performance of two-layered stratified buildings is significantly affected by the inlet opening positions. Moreover, the indoor flow direction is considerably changed owing to the multi-zoning of the indoor space. Although we employed only a generic two-layered model, this study clearly highlights the importance of considering multi-layered buildings for a better understanding of the ventilation performance.