Rain and snow event cooling effect: a comparison on outdoor and indoor thermal comfort in Ardabil, northwest of Iran

Abstract

Human thermal comfort is influenced by different climatic parameters. The effect of rain and snow events on human thermal comfort has been less explored in the available literature. The work presented here investigates outdoor and indoor thermal comfort using the physiological equivalent temperature (pet) and wind chill temperature (WCT) indices and Givoni bioclimatic chart for rainy and snowy days as well as a day prior to and a day post snow and rain events in Ardabil. Results indicated that snow and rain events have cooling effects on both indoor and outdoor thermal sensation. The cooling effect of rainy and snowy days is higher than a day prior to and a day post events. Also, the cooling effect of the snow and rain increases by the intensity of the events (> 10 mm/day). Based on the PET and WCT outputs, the cooling effect of the snow events with intensity higher than 10 mm a day is about 1.77 and 0.80 °C less than events under 10-mm a day intensity. The same pattern was observed for rain events. Analysis of the cooling effect of event duration on outdoor thermal comfort indicated that the events with more than 2-day duration have more cooling effect on thermal sensation. Finally, due to different cooling effects of snow and rain events on indoor thermal sensation, different types of bioclimatic strategies should be used inside the buildings during snowy and rainy days in Ardabil.