كليدواژه :
شرايط جغرافيايي , زاويه تابش خورشيد , جهت وزش باد غالب , تعداد روزهاي يخبندان , يخچالهاي سنتي
چكيده لاتين :
Given the variety of climates in Iran, different approaches have been adopted, since long time ago, to make harsh environments tolerable. In this respect, architects tired to take the utmost advantage of climatic conditions. A typical example for this is ice houses. The ice needed for ice houses was provided during the freezing months of the year to be saved and used in hot summers. Thanks to their technical mastery and experience, architects designed the structural elements of an ice house. The icehouses were generally constructed in hot regions where the number of freezing nights of the year and the temperature difference between winter days and nights was considerable. However, ice houses can be seen in cold climates as well. Ice houses can be divided into two distinct structural spaces: ice-producing space and ice-keeping space. The former includes a shading wall and an ice-producing pool. The latter includes a ice-keeping pit. The structural spaces of ice houses may differ from each other depending on location and climatic conditions.
Data were gathered through library sources and field studies. First, different climates of the hot regions in the country and their impact on the ice houses were studied. In this respect, the angle of solar radiation, the number of freezing days of the year and the direction of dominant wind are among the most important factors. The cities with highest number of ice houses were selected. Also, the climates examined included cold, desert hot and dry and semi-desert hot and dry.
In practice, the regions with traditional ice houses were detected. Then, the climatic conditions of the regions were studied based on recorded tables, diagrams and climatic regimes in Iran. There was no major change in local climates since the time of constructing ice houses. Therefore, it was possible to determine the climate at the time of constructing ice houses under study. In order to classify ice houses in terms of structural and formal features,6 kinds of ice houses were examined in different regions.
Of the important factors influencing the form of ice houses is geographical conditions of the region in where the ice house has been built. In this study, the impact of each geographical factors, as classified by other researchers, on the structural elements of ice houses was examined. The number and kind of structural elements of ice houses depend on latitude, the angle of solar radiation and the average temperature of winter in the region. From the northern towards southern parts of the country, whereas the latitude and the number of freezing days decrease, regional temperature and the angle of solar radiation increase. On this basis, the structural and formal characteristics of ice houses may change. For example, the simplest form of ice houses, including just one pit, can be seen in cold regions (mountainous parts of the country in north west side). In desert hot and dry regions of the country, however, ice houses have different structural elements. The form of ice houses is, to a large extent, under the influence of the angle of solar radiation. For instance, in cold regions of the country ( northern cities) ice houses lack shading wall due to oblique solar radiation. On the contrary, as we approach the central regions, the height of shading walls increases; in desert climate, ice houses have the tallest shading walls. Likewise, ice keeping spaces are usually on the ground surface in regions where solar radiation has no major impact on them. However, as the angle of solar radiation increases, the ice-keeping spaces have also taller walls to keep off the solar heat. In addition, in regions where the sun radiates almost vertically, the ice-keeping spaces have been built in the northern side of shading walls to escape from solar heat as much as possible. Similarly, wherever the number of freezing days has been considerable, the structure of ice houses is as simple as possible. The direction of dominant wind is also an important factor when building an ice house. For example, in cold regions, the shading walls have been built in the same direction of the dominant wind.
