Thermal Comfort Characteristic of 5 Patterns of a Persian Garden in a Hot-Arid Climate of Shiraz, Iran

Thermal comfort in the open spaces is a significant parameter in public mentally and physically healthy. Increased hot days of cities because of the urban heat island is the common phenomenon in cities. This phenomenon effect cites quality by a different aspect such as air quality, Use of fossil fuels etc. therefore, cooling strategies in the urban and urban park’s design is one of the important issues of the designers. Urban parks have a significant effect on heat stress mitigation. Persian garden is known for its microclimate effect on pedestrians, so different patterns of Persian garden is selected to be analyzed in terms of thermal comfort condition on the hottest day of summer so far in the dry hot climate of the Shiraz(12^th of July 1998 with the maximum 42°C Ta). In this paper 8 conditions are simulated by Envi-met3.1 to get environment data of these patterns and also the Rayman model is used to calculate the Physiological Equivalent Temperature (PET) as the proper thermal index for outdoor condition. The results demonstrate that alteration of Shortwave radiation both direct and diffuse conditions and mean radiant temperature are affected by both sky view factor and the orientation of the Persian garden. Pavilion location has an important effect in mitigation of the Tmrt by preventing the afternoon powerful sun rays through to the paths in the End.E-W pattern. Therefore, this pattern has a better condition of PET value than the others in Shiraz setting.