Objective is to find out the optimum dimension of BTHE using Ansys Software at Indian climate condition. For this BTHE is used which reduces conventional air conditioning load and save energy sources for reducing the heating or cooling load of residential or any buildings. However, BTHE system can improve the indoor thermal comfort and reduce greenhouse gas emission. Core objective is to determine the exact tonnage capacity of BTHE for specific load in cooling and heating mode with respect to design and materials of BTHE. Methods/Statistical Analysis: BTHE consists of one or more tubes which are lied under the ground at buried depth for cooling in summer and for heating in winter and the air is to be supply in any building. There is a constant temperature at the depth of 3m from ground level by experimental setup of Temperature measuring probe throughout the year. The research in CFD simulations were performed on various performance measurements, with different length of heat exchanger. Findings: From the simulation analysis dimension of Buried tube heat exchanger (BTHE) could be found. This was done both for Vertical and Horizontal orientation.