Determining new threshold temperatures for cooling and heating degree day index of different climatic zones of Iran

Iran is a country with a variety of different climates. Determining the threshold temperatures suitable for providing thermal and climatic comfort is necessary and vital to its population well-being. This research presents new threshold temperatures in order to calculate the degree day index required for heating and cooling by taking advantage of the 12 stations that are representative of the diversity of Iran's climate. Using Olgyay diagram, different bioclimatic ranges of 12 weather stations and their frequencies were compiled, processes and analysed. Mean daily data of temperature and relative humidity were used for the period of 1950e2010. Based on the frequencies of temperature readings falling in Olgyay's diagram comfort zone, representive temperature thresholds were selected based on 40 to 60 percentiles or (P20), 25e75% percentile (P50) and the threshold of 10e90% percentile. The findings of this study shows that Mashhad with 29.6% and Anzali with 2.33% of frequencies, have experienced the maximum and minimum days of comfort. After analyzing various percentiles to determine the threshold temperatures, it was observed that there is a little difference among the stations for determining the minimum threshold for the comfort. Differences are more obvious in the maximum thresholds. In total, minimum base temperatures (HDD) belonged to Ardabil stations that were 20.50, 20.90 and 20 deg C for P20, P50 and P80 respectively. The maximum temperature for calculating CDD with values of (P20 ¼ 25 C; P50 ¼ 26.25 C; P80 ¼ 27.50 C) is dedicated to Zabol station. The findings present more reasonable thermal comfort thresholds that can be used by architects, engineers and policy makers to achieve, in turn, more energy efficient homes and high quality indoor and outdoor living environments

Projecting the impact of climate change on design recommendations for residential buildings in Iran

The outdoor climate is changing. In order to assure thermal comfort in new and existing residential buildings we need to revise and adapt our building designs. Therefore, 10 meteorological stations in Iran were selected to investigate and predict the influence of climate change on the local climate diversity and variability. In order to provide a comfortable and healthy indoor environment, bioclimatic design recommendations during early design stages were revised, including during the two periods of 1986-2015 and 2020-2050. A modified Givoni`s bioclimatic chart was used to visualize the climate variation and to inform designers about accurate and climate-proof bioclimatic design recommendations. The second-generation Canadian Earth System Model was used to predict changes in the maximum and minimum temperature and relative humidity components of future decades. Based on Representative Concentration Pathway (RCP) 2.6, RCP 4.5, and RCP 8.5 for the greenhouse gas emission section of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, the effects of climate change on different cooling and heating strategies were examined. The findings of this study showed that for all the studied stations, apart from Abadan, the trend in temperature increase over the coming decades is not unforeseen. The use of heating strategies will decrease, and the use of cooling strategies will increase. Finally, this study presents an adjusted bioclimatic chart of Iran and quantifies the adaptation measures to climate change to reduce energy use and avoid overheating

Determining new threshold temperatures for cooling and heating degree day index of different climatic zones of Iran

peer reviewedIran is a country with a variety of different climates. Determining the threshold temperatures suitable for providing thermal and climatic comfort is necessary and vital to its population well-being. This research presents new threshold temperatures in order to calculate the degree day index required for heating and cooling by taking advantage of the 12 stations that are representative of the diversity of Iran's climate. Using Olgyay diagram, different bioclimatic ranges of 12 weather stations and their frequencies were compiled, processes and analysed. Mean daily data of temperature and relative humidity were used for the period of 1950e2010. Based on the frequencies of temperature readings falling in Olgyay's diagram comfort zone, representive temperature thresholds were selected based on 40 to 60 percentiles or (P20), 25e75% percentile (P50) and the threshold of 10e90% percentile. The findings of this study shows that Mashhad with 29.6% and Anzali with 2.33% of frequencies, have experienced the maximum and minimum days of comfort. After analyzing various percentiles to determine the threshold temperatures, it was observed that there is a little difference among the stations for determining the minimum threshold for the comfort. Differences are more obvious in the maximum thresholds. In total, minimum base temperatures (HDD) belonged to Ardabil stations that were 20.50, 20.90 and 20 deg C for P20, P50 and P80 respectively. The maximum temperature for calculating CDD with values of (P20 ¼ 25 C; P50 ¼ 26.25 C; P80 ¼ 27.50 C) is dedicated to Zabol station. The findings present more reasonable thermal comfort thresholds that can be used by architects, engineers and policy makers to achieve, in turn, more energy efficient homes and high quality indoor and outdoor living environments