Suggesting a Method to Estimate the Cooling Time of Iranand its Simulation in the Future

One of the criteria for estimating the amount of energy used for cooling and heating is the degree hour. The aim of this study was to select the most appropriate method to calculate the cooling degree hour and simulate these parameters in the coming decades. Firstly, by using EH5OM model data from Max Planck Institute in Germany, the hourly temperature data at a time interval of 3 hours (8 data per day) in Iran territory during the period of 2025-2060 under A1B scenario of the International Committee of Climate Changes and resolution 1.75×1.75 of longitude and latitude degree were simulated.Then the hourly temperature data separetely with 0.27×0.27 of geographical altitude and latitude degree which covers an area with dimensions of approximately 30 x 30 km of Iran was downscaled by the fourth edition of the regional climatic model. By using temperature threshold 23.9° C degree, the required hours of cooling per hour in each day and their monthly calculation were extracted in a matrix of size 2138 × 3456. In this matrix, the rows indicate the total of monthly degree hours and the columns indicate the cells. Then the hours of 09, 12 and 15 Zulu were selected from the existing hours and the total monthly average of degree hours of 6 warm months of the year (April to September) were calculated on a matrix of size 2140×12 and its maps were drawn in Surfer software. The trend amount of the said degree hours was calculated in MATLAB software and through the Mann-Kendall test on 2140×12 matrix and their monthly process maps were drawn. The results showed that spring season sepecially April and May months will have the greatest hour cooling need and the lowest one will be in summer, especially in August and September. Maximum cooling needs in the hours of 09 and 12 Zulu in April and May in Khuzestan plain and 900-1000 hour degree in the southern coast hinterlanda and the lowest one at 15 oclock zulu, On the hills of Azerbaijan, Zagros, Alborz and Khorasan in June, July, August and September will be zero hour degree. The positive trend of cooling need is in the West and southern banks at every three hours of the under study in the months of April, May and June and July which indicate the warmer temperatures in the first half year. Central belt and across the eastern and northern half of the country except in June has no trend in the rest months of the year.