Thermal Comfort Conditions at the Platforms of the Athens Metro

The current study aims at the comparison of the field measurements at the platforms of the Athens Metro with those recommended by international standard thermal comfort and to the investigation of the relationship of environmental parameters between platforms and the outdoor space. The levels of air, operative and globe temperature as well as air humidity and air velocity were continuously monitored at the platform space of two stations with different depth and design features in summer. The predicted mean vote (PMV) model and the predicted percentage of dissatisfied (PPD) index were used. The results reveal that the operative temperature at both stations is far from the traditional still-air comfort zones. For the case of elevated air movement of 1.2 ms-1 and considering the occupants have local control of air speed, 20.3% of the values at the station with the greatest depth do not exceed the upper limit. Furthermore, 64% of the variation in air temperature at the platform of the station with the smallest depth is explained by outdoor air temperature, while the corresponding percentage for the station with the greatest depth is 29%. Passengers experience sudden change of air temperature and PMV, especially at the station with the smallest depth, during their transition from the platform to the interior of air-conditioned train carriages and vice versa.