Determining the influencing factors on the performance of solar chimney in buildings

Solar chimney as a reliable renewable energy system has attracted increasing attention from engineers to conquer the current energy crisis. The main challenge of designing a solar chimney is to optimize its performance with the lowest cost. Based on literature review, thirteen key influencing factors were obtained and classified into four groups, including configuration, installation conditions, material usage, and environment. Statistics of experimental studies showed that the overall tested range is still limited which suggests more future experiments. To enhance the performance, a solar chimney is suggested with possible high cavity and solar radiation, a cavity gap of 0.2-0.3 m, equal inlet and outlet, a height/gap ratio of around 10, an inclination angle of 45-60 degrees (for roof solar chimney considering latitude), an appropriate opening of room, double/triple glazing, a 5 cm thick insulation wall, and a solar absorber with larger absorptivity and emissivity. These optimum values may not be applicable to all configurations as they are interdependent. Although external wind shows significant influence on solar chimney, solar chimney design can be undertaken without considering the effects from wind. This review will provide a useful technical guide for researchers and professionals regarding the optimum designs of solar chimney in buildings.