Computer aided analysis of earth-air heat exchanger designed to ensure thermal comfort of a building

In this study, passive geothermal cooling technology is used to provide thermal comfort of a typical building in Elazığ (Turkey) by using Earth-Air Heat Exchanger under steady state conditions. Thermal performance of EAHE is evaluated in ANSYS Fluent 12.1 program by using Computational Fluid Dynamics. Average of maximum temperature data of Elazığ in July 2014 is used to analyze thermal performance of EAHE. Numerical analysis are performed for thermal performance of EAHE at different soil depths (H = 1 m, 2 m, 3 m) using two different materials such as PVC and steel (%0.5 C). Problem is solved at steady state in three-dimensional model by using different values of the Reynolds number in turbulent flow (Re = 5x103, 104, 15x103, 2x104, 4x104, 6x104, 105). In the result of analysis, maximum temperature decrease takes place at 3 m deep buried steel pipe (%0.5 C) by 27.67 K, and minimum temperature decrease occurs at 1 m deep buried PVC pipe by 12.36 K. It has been found that the best thermal performance occurs in the smallest air intake speed and also the type of EAHE material does not affect thermal performance significantly. Best thermal comfort requirement for thermal analysis with numerical models at different soil depths is obtained in 1 m soil depth. Keywords :Earth Air Heat Exchanger, Computational Fluid Dynamics, Temperature, Average Nusselt Number