Urban oasis: A thermal retrofitting proposal for the Santiago metro

Abstract

The underground stations of the Santiago Metro can experience temperatures of around 32°C in the platform area during the summer season, thereby directly affecting public transport users. Similar situations occur in other subway systems of the world and the solutions implemented have not been able to solve the problem entirely, even resulting in high operating and maintenance costs. This article presents a passive thermal retrofitting proposal that takes the Tobalaba L1 Santiago Metro station as its case study. Taking advantage of the existing ventilation shafts, an evaporative cooling system was simulated that seeks to reduce the temperature in the platform area and at the same time contribute to reviving the public space on the surface. The proposed solution made it possible to decrease the average temperature 2.5°C in the summer and 3.6°C in the winter. This demonstrates that it is possible to match the scope of some active solutions, but with lower costs associated with zero energy consumption and the use of existing elements, and with improvements in the conditions of public space by incorporating the qualitative factor from architecture.