Evaluation of two earth–air heat exchangers efficiency of different pipe materials within a warm temperate climate

The Earth-Air Heat Exchanger (EAHE) system was used for many years for both primary heating and cooling applications, especially in the building sector. Its energy performance can be influenced by three principal factors: the EAHE pipe material, the airflow rate, the soil characteristics and the moisture content. The state of the art shows a divergence about the effect of the pipe material on the performance of the EAHE. The aim of this study is to provide an adequate response to this problematic based on experimental analysis. In this regard, we tested two EAHEX of different materials: PVC and Zinc. The comparative study was conducted under a warm temperate climate in the north of Algeria. The data analyses showed that the pipe material can significantly affect the EAHE performance during periods when the EAHE passes from heating to cooling mode. Furthermore, the air outlet temperature differences provided by EAHE Zinc and those of PVC up to about 7.5°C