Effects of large skylights on lighting and thermal environments in underground public transport hubs: A case study in Shenzhen

Large skylights in underground public transport hubs are designed to introduce natural light and reduce the energy consumed by artificial lighting. Although large skylights can improve the lighting environment of underground public transport hubs, they also increase energy consumption due to solar radiation. Therefore, there is an urgent need to balance the improved lighting and energy consumption associated with large skylights and to determine the optimal design scheme. There are few studies on the lighting and thermal environments of underground public transport hubs, and the optimal design scheme for large skylights is unclear. Therefore, in the current study, field tests were conducted to analyze the lighting and thermal environments of two underground public transport hubs located in Shenzhen: Shenzhen North Station and Futian Station. In addition, multiobjective optimization was carried out for the large skylight at Futian Station. The results showed that most passengers were satisfied with the lighting and thermal environment under large skylights, but they were less satisfied in the summer than in the winter. Therefore, appropriate shading measures should be considered to reduce the effect of large skylights on passengers' thermal comfort in the summer. Furthermore, the results of multiobjective optimization indicated that the large skylight at Futian Station led to a 28.1 % reduction in annual air conditioning-induced energy consumption, a 31.5 % increase in the lighting performance index (UDI), and a 43.8 % increase in the human thermal comfort index (CTR). The results of this study could provide guidance for the design of large skylights in underground public transport hubs.