Performance Analysis of Earth Air Pipe Heat Exchanger as Passive Cooling and Heating System

Abstract

The working principle of EAPHE, as passive heating and cooling system, is based upon the newlineutilization of soil as source and sink of heat for winter heating and summer cooling respectively. newlineEAPHE consists of long pipes laid under the ground having one end open in air and the other newlineconnected to the air intake of buildings. Hot or cold outdoor air is passed through the buried newlinepipes for bringing change in its temperature before supplying it into the building. A turbulent newlinemodel has been developed based on Computational Fluid Dynamics (CFD) to predict the newlineperformance of EAPHE system. Model was simulated in ANSYS FLUENT and performance newlineof proposed models has been investigated, and comparisons were made in terms of outlet air newlinetemperature, sub-soil temperature at 0.05m and 0.25m from pipe surface, heat transfer rate, newlinecoefficient of performance (COP) and effectiveness of the system. The developed model has newlinebeen validated against the numerical and experimental results of published research papers. newlineCommon configuration of EAPHE system usually consider straight or U shaped geometrical newlinelayout, which requires a large installation area which is not suitable for installation under small newlinehome or office setup in a densely populated country like India. In present study this major newlinedrawback can be overcome by using helical shaped air pipe layout, which reduces the newlineinstallation area up to 77% compared to that of the conventional straight or U shaped pipe newlinegeometry. Installation area of the helical air pipe layout depending upon pitch of the helical newlinepipe and coil diameter. newline