Parametric study of a novel combination of solar chimney and radiative cooling cavity for natural ventilation enhancement in residential buildings

The application of radiative cooling (RC) is expanding to a diverse research field, with some current studies trying to apply RC for natural ventilation. One proposed strategy is to use RC for the enhancement of solar chimney (SC) ventilation, and this strategy has been proven in a dry temperate climate. However, geographical locations and other design parameters may affect the performance of this natural ventilation strategy, and the conditions in which SC-RC ventilation performs best need to be investigated. This parametric study examines the performance of a novel SC-RC ventilation with six different parameters. The six parameters are the RC emitter's convection cover, building's thermal mass, RC cavity gap, internal heat gain, climate, and fan usage. Transient 2D computational fluid dynamics (CFD) simulations with Ansys Fluent were conducted to analyse the SC-RC ventilation's optimal design and working conditions. A convection cover on the RC emitter, a thermal mass wall material, a smaller RC gap, and a relatively low internal heat gain help the SC-RC achieve a cooler room and higher ventilation flow rate. Overall, the novel SC-RC ventilation performance is better than a conventional SC, except in humid climates. In dry climates, the SC-RC has the potential to create a maximum 2 degrees C temperature reduction, with a daily average room temperature of 0.56 degrees C lower than ambient. This cooling performance of the passive SC-RC ventilation is better than the fan-assisted SC-RC. Also, the SC-RC can achieve a daily average of 2.1 ACH, which is 0.4 ACH more than the conventional SC.

Automated summary

This study investigates a novel strategy of enhancing solar chimney ventilation using radiative cooling. By conducting parametric studies, the optimal design and working conditions of the SC-RC ventilation are determined. The results show that the performance of the SC-RC ventilation is better than conventional solar chimney ventilation in dry climates, with temperature reduction and increased ventilation flow rate.