This paper presented an overview of the passive strategies for ventilation and air-conditioning energy saving in underground metro stations. The strategies were relevant to building envelopes, piston effect and natural cold sources. This review found that the building envelopes had made minimal contribution to the research literature and might not be applicable to the underground stations. The piston effect was the most popular passive strategy in research community for its great energy saving potential. The ground cooling strategy was another promising option for air-conditioning energy saving but it was often overlooked due to its high R&D costs. The authors hope that this study can promote the adoption of different passive strategies for the ventilation and air-conditioning energy conservation in underground metro station buildings.
Keywords Underground; Metro station; Energy-saving; Passive strategies; Ventilation; Air-conditioning