Sustainable Design in Metro Stations

In addressing the Global Energy Crisis, engineers have the social responsibility to find and implement practical solutions. This paper discusses thesustainable heating, ventilation and air-conditioning (HVAC) design concepts that can be applied in metro systems.The use of Platform Screen Door (PSD) along the underground station platform to isolate the station from the tunnel has a positive impact on the overallenergy consumption of the metro systems in tropical regions (e.g. Singapore, Thailand, Malaysia, etc.) and subtropical regions (e.g. Hong Kong,Guangzhou, Shanghai, etc.). During cooler months, the concept of free cooling by introducing more outdoor air in seasoned countries can further reduceenergy consumption as well as improving indoor air quality.To contribute on sustainable development, engineers should participate in the overall planning of the metro stations with other stakeholders. Effective useof space is a key strategy in mitigating the challenge of land scarcity in developed urban cities. This planning may include (1) utilizing the space createdincidentally due to metro construction by converting it to commercial areas instead of backfilling it, (2) integrate development above metro stations or (3)connecting the metro stations to nearby developments to mitigate impact to the aboveground traffic.For sustainable design, Central Chiller Plant can be considered for adjacent stations and their connecting developments. Apart from saving initial costand running cost, this approach also saves the overall land space. To further release space above ground for other usage, open top vent shafts can bedesigned to reduce the size of the aboveground structure.There are other sustainable designs in metro systems that are related to HVAC design. Taking the lighting system for example, the use of “Lightwithout Fitting” (LwF) concept with Light-emitting Diode (LED) lighting is an ongoing trend to bring a new aesthetic experience to the public. It notonly reduces the lighting energy consumption, but also reduces the cooling load requirement.Examples from various projects in Singapore and Hong Kong will be referenced in this paper. Other sustainable measures e.g. Variable Speed Drive(VSD) for pumps and cooling towers, outdoor air control, regenerative energy, etc. which have been used in metro systems are also covered in this paper.