A numerical investigation of energy-saving potential of inner solarshade film: A case study of the National Aquatics Center, China

Abstract

Transparent or semitransparent roof structures of sports venues have attracted much architect's attention, but the energy consumption of these buildings must be considered as a crucial aspect too. For the 2022 Beijing Winter Olympics games, the curling sports event will be held in the China's National Aquatics Center. The roof of this center is made of double-layer ETFE film (Ethylene-tetra-fluoro-ethylene, a semitransparent film), which allows a large amount of external solar radiation to enter the main sports hall, leading to huge cooling demand for the indoor ice rink. To reduce energy demand, in this study, an innovative solar shade film was developed and installed between two air cushions in order to reduce solar radiation heat gain. Experimental and numerical studies were carried out to investigate the effect of environmental factors (including seasonal and weather variation) and film materials (transmittance) on the energy-saving potential. Results indicated that high outdoor solar irradiation and air temperature have a significant impact on the energy-saving potential. Meanwhile, the low transmittance of solarshade film reduced solar radiation reaching the room but significantly increased lighting energy consumption. To maximise the energy-saving potential, a transmittance of 0.25 is recommended for the China's National Aquatics Center, with significantly improved predicted total annual energy-saving of 467.3 MJ/m2.