Lessons from climatic architecture of the passages of Kashan, A field study in the traditional part of the city

Traditional architecture of the historical cities in Iran contains valuable lessons related to architecture and urban design. A considerable group of these strategies are those that are used in outdoor urban spaces in desert cities providing a safe and sustainable microclimate to live in the harsh desert for more than thousands of years. This article will decode these strategies by doing field study in hot summer and cold winter of Kashan، a historical city of Esfahan Province by nearly 7000 years of civilization in the edge of “Dasht Desert” in the centre of Iran. The weather data are collected in 11-12 July 2011 and 11-12 Jan 2012; the summit of summer and winter. A mobile Kestrel Personal Weather station is used to collect the data in the traditional part of the city such as Bazar، mosque yard، wide and narrow streets، covered streets (Sabat) and squares. The data are collected for every 30 second to clarify the differences in microclimate condition in each outdoor space. A Kestrel weather station that is fixed on the roof of a historical house is used to collect the reference data as local climate. All the data are analyzed by UTCI (Universal Temperature Climate Index) as one of the most reliable and newest outdoor thermal index. The collected weather data are compared in four levels of: 1) long-term city climate، 2) short-term city climate، 3) local climate and 4) microclimate. The long term meteorology data of Kashan is used to show the ordinary climate condition of the city in different years. The hourly meteorology data of kashan in the days of observation is used to show the short term city climate. The data collected on the roof is used to show the local climate of the traditional part of the city. The data collected by the moving Kestrel in the observed outdoor spaces is used to show the microclimate changes. To speed up the analyzing process a new software is designed called SIKRON that is able to convert the meteorology data of temperature and humidity on the psychrometric chart of the outdoor thermal index UTCI. The results of this research has shown that the effect of architectural strategies used in different outdoor spaces، have very good ability to modify the microclimate providing a better thermal condition for pedestrians in hot summer and cold winter of the city.