Impact of elevated outdoor MRT station towards passenger thermal comfort: A case study in Jakarta MRT

Comfort of the train passengers is the main priority of modern mass rapid transit (MRT) management. Objective of this paper is to investigate the thermal comfort of the elevated MRT station in tropical climate. The first step of this study was to conduct literature review on human thermal comfort, environment ergonomics, computational fluid dynamic (CFD), computational aeroacoustics (CAA), and predicted mean vote (PMV). Air quality in elevated MRT station was measured based on several parameters: relative humidity, wind speed, temperature, and wind direction. A 3D model of MRT designed was used to describe existing condition prior to simulations with CFD and CAA softwares. Predicted mean vote is arranged based on the value of metabolism, wind speed, ambient temperature, mean radiant temperature, amount of insulation from clothing, and relative humidity. Whereas predicted percentage of dissatisfied (PPD) can be derived from PMV calculations. The analysis shows that the average PMV of existing condition for elevated outdoor MRT station is 3.6 (extremely hot) with PPD is 100% (all passengers felt discomfort). Some recommendations to reduce heat stress were addressed such as: adding plant, changing materials of the MRT station, and change the design of the elevated MRT station. Modifying open elevated MRT station into indoor elevated MRT station with installing six units of AC (2pk, ±23°C) can improve air quality and maintain the thermal comfort scale of PMV to be -0.04 (comfort) with PPD of < 8%. Based on the analysis, it can be concluded that the most suitable design for elevated MRT station in tropical climate (hot and humid) is indoor MRT station with pay attention to both direct and indirect heat exposure that hit the station.