Assessment of the cooling potential of an earth-tube heat exchanger in residential buildings

Abstract

At present, we can observe the increase in glazing area of all types of buildings. Large size of south windows to allow for high passive solar heat gains during the heating period and can reduce primary energy demand. But, on the other hand, the big value of glazed openings percentage may cause low quality of thermal comfort inside the living and working spaces in the warm part of the year. The current paper presents results of computer simulations and experimental investigations of thermal performance of earth tube heat exchanger (ETHE). This natural geothermal based system can decrease heating loads and significantly reduce the room air temperature during summer seasons. The authors of this work used energy simulation software - EnergyPlus to estimate the cooling potential of earth–air–pipe systems in residential buildings for different Polish climate conditions. For these simulations three important annual average soil parameters as: surface temperature, the amplitude of surface temperature and the phase constant of this temperature were calculated by computer program CalcSoilSurfTemp. The results of longstanding experimental measurements of double pass earth air heat exchanger made of PCV tubes are presented in this paper, too.