The impact of solar chimney geometry for stack ventilation in Malaysia's single storey terraced house

Abstract

In terms of passive cooling design in housing, tropical climates present the most difficult problem to solve. The climatic conditions of the tropical regions are characterized by high air temperatures, high relative humidity and very low wind speeds. These make the environmental conditions uncomfortable. This situation arises from the low air velocity and high temperature experienced during day time. The wind effect is also not well utilized especially in the usual single sided ventilation. The field measurement study on an existing house indicated that the basic design of single storey terraced house is not effective in providing natural ventilation for achieving thermal comfort. It is hypothesized that solar–induced ventilation may be a viable alternative. Therefore this paper discusses the impact of solar chimney geometry for stack induced ventilation strategies on a single storey terraced house model under Malaysian conditions. The solar induced ventilation study involved computer simulation using Computational Fluid Dynamics where air movement and solar radiation simulation are the major variables. Validation of CFD FloVent was done by comparing the results with field measurements and it showed a good agreement. Further development of the solar induced ventilation designs have been made and evaluated to attain solar chimney geometry. The simulations were performed on a selected day of one year. The result showed that the solar chimney geometry of 3 x 1 m area and 3.5 m vertical height provided continuous air movement where highest velocity could reach 0.6 m/s (on 21st March, on north-south orientation).