Numerical Study of Cooling Buildings with Cylindrical Roof Using Surface-to-AirHeat Exchanger

In this study, a hybrid cooling system, including ground-to-air heat exchanger and a cylindrical roof is studied. In the proposed system, the ground-to-air heat exchanger cooling system passive system and cylindrical roof as natural ventilation, to achieve thermal comfort conditions and also supplies the required cooling load of the building in the city of Semnan have been used.The outside air is then passed over the roof, increasing speed and reducing pressure leads to indoor air is evacuated where the relative vacuum in the room leads to cool air in underground channels conducted into the building. Simulation of three-dimensional air flow in the heat exchanger surface-to-air, cylindrical roof and the room was solved by Fluent software. For this building and the heat exchanger in a channel with dimensions 120 × 40 × 40 meters have been placed as computing space. The data, ground-to-air outlet temperature of the heat exchanger was calculated numerically with MATLAB computer code and finally the temperature was brought to the room. The results show that the system with 2 tube dr = 0.082 for the space Lr = 7.14 can be abstain comfort condition in Semnan. Also according to the results, opening for the roof span is Ar = 0.082. In this study, the effect of different factors such as wind speed, average room temperature, the aperture diameter of roof, diameter, length and number of tubes ground-to-air heat exchanger was investigated.