Analysis of Top Openings for Underground Transport Hubs Using Sunshine Hours
The development of underground transport hubs has become an important approach to address urbanization problems such as heavy traffic and land deficiency.Top openings in the underground transport hubs can enhance underground daylighting and natural ventilation.However,the underground space will receive more solar radiation through top openings,where a thermally uncomfortable environment would be formed on summer days.It is necessary to understand the relationship between opening design parameters and thermal environment index,so as to assist the designers to improve design proposals.This study proposed an analytical method to evaluate the thermal environment based on sunshine hours.This method can qualitatively and quantitatively analyze the distribution of sunshine hours in the analyzed underground space using a sunshine simulation tool.Hourly variation of solar radiation intensity is also considered through the weight analysis method.The relationship between opening design parameters(i.e.opening rate,number of openings,underground space height)and sunshine hours has been discussed in this study.An underground transport hub located in Guangzhou is selected as a case study object to demonstrate the application process of the proposed method.The results show that the proposed method can assist the designers to determine top-opening design proposals with better thermal environment and lower building energy consumption for underground transport hubs at the scheme design stage.
underground transport hubtop-opening designsunshine hoursthermal environment analysisscheme design stage