Effects of buried pipes configuration on the performance of an underground passive cooling system in a desert city of Iran

Abstract

Kerman is a very old city located on the outskirts of the deserts in south-central Iran. Since antiquity, the residents of the city utilized the low temperature of the soil beneath the surface of the ground to preserve foods and to make the water cold for drinking in the summer. In this study, the depth of the ground is used as a heat sink, which has the added benefit of not disturbing the historical appearance of the city. Two different configurations of buried pipes under the ground are examined to determine the most appropriate one for cooling the building. In the first configuration (case A), water flows to the depths of the soil through a vertical pipe with the length of h , and then flows in a horizontal pipe with the length of l at the depth of the ground, and then returns to the ground surface through a vertical pipe. In the second configuration (case B), water flows through a vertical pipe to the depths of the ground and then returns to the ground surface through another vertical pipe, and this pattern is repeated several times. The outlet flow of cold water from the buried pipes flows directly into the embedded pipes under the roof. A numerical simulation is performed to obtain the variation of temperature and fluid flows in the building and buried pipes. Comparison of the results reveals that the temperature of the building is reduced with a shorter pipe length by applying case A. • Underground passive cooling system is used for cooling a building in a desert city. • Two different configurations of buried pipes are considered for cooling a building. • The proposed method has a great advantage compared to many other energy alternatives.