Thermal comfort analyses on jogging trails: The effect of trail direction and tree shading on trial surface and physiological equivalent temperatures

Abstract

Jogging trails have been constructed in residential areas in Kuwait City to encourage people to exercise in outdoor spaces. The weather is hot and arid for most of the year. To create a comfortable and healthy local microclimate condition, trails were constructed along a certain direction with respect to the direction of the main prevailing wind and shaded with trees. In this study, the combined effects of tree shading and trail direction on trail surface temperature and physiological equivalent temperature (PET) were investigated. The prime focus is on a PET thermal comfort range between 21.6 °C and 30.1 °C and the period between 5:00 p.m. and 10:00 p.m. The results indicate that the shade of trees effectively protects the trail surface if the shaded trail is along the N–S direction, but it is ineffective if the shaded trail is along the E-W direction. PET analyses indicate that tree shading is irrelevant to thermal comfort only in spring, during which the thermal comfort of all trials was neutral between 5:00 p.m. and 10:00 p.m. E-W is the most comfortable trail in winter and summer. The trees along the E-W direction trail slow down wind speed and increase the relative humidity, which is desirable in arid environments. The E-W trail is the most comfortable because the trees protect people from hot winds in the summer and cold winds in winter. The results of the present investigation provide information of interest for urban designers, who can attain comfortable and healthy local microclimate conditions by choosing the correct trail direction and considering tree shading.