Design and Analysis of Earth-Air Heat Exchanger for Room Heating and Cooling

The Earth Air Heat Exchanger (EAHE) is a promising technique which can effectively be used to reduce the heating and cooling load of a building by heating the air in winter and vice versa in summer. The main concern is to suggest ways for energy saving and minimise heating and cooling energy demands and carbon emissions in private residences. An EAHE utilizes the thermal mass of the soil surrounding or beneath the building in order to heat or cool incoming air. With the ground’s large thermal capacity and relatively stable temperatures, outdoor temperature variations are dampened and ventilation heating and cooling loads are reduced. At a depth of 2-3 m under the surface of earth, temperature of soil remains constant at 22 ˚C for whole year. EAHE consists of buried tubes at this depth and atmospheric air is passed through this tube. During winter season the atmospheric air temperature is lower than 22˚C for most of the times of the day so heating of air will take place in the Earth Air Heat Exchanger and proper conditioned air will be obtained at the outlet of EAHE. Similarly in summer season the atmospheric air temperature is greater than 22 ˚C for most of the times and hence cool air will be obtained at the outlet of EAHE. To determine the best material for EAHE in order to get optimum results aluminium and copper tubes of same dimensions will be used. After performing experimentation results will be studied and the best material will be selected considering various parameters.