Thermal comfort assessment of non air-conditioned railway coach in Central India during extreme summer

Abstract

Assessment of thermal comfort for residential buildings has been in trend for years. However almost all the field surveys carried out in recent years, have solely focused on static occupational environment, such as offices, houses, schools etc. Thus, an attempt here has been made to assess the thermal comfort of a dynamic environment for ventilated moving passenger trains in India. In this context, Passenger’s Comfort Vote (PCV) has been collected from passengers who have travelled in a naturally ventilated railway coach during summer 2022 in India. More than 1500 passengers have participated, and recorded their responses in either paper based or digital questionnaire sheet. The study results could contribute towards the enrichment of global thermal comfort database and further for improvement of passengers’ travelling experience during summer. The PCV value for male passengers is found to be slightly more (1.4) as compared to female passengers (1.3). A moderately strong correlation is found between passengers’ comfort response and operative temperature (R2 = 0.78, p < 0.001). The regression operative temperature at optimum thermal comfort condition is found to be 33.2 °C. Air velocity, which primarily depends upon, windows, fans and seat location in the coach, also seems to cause predominant influence on thermal comfort in a ventilated coach. The upper seat is found to be least comfortable with an average sensation vote (PCV) of 1.7 while passengers at window seats are comparatively more comfortable (PCV 1.33).