Improvement of earth-to-air heat exchanger performance by adding cost-efficient soil

Geothermal research advances earth-to-air heat exchanger (EAHE) technology, offering promising air conditioning solutions for all buildings. Our study targets improved energy efficiency for the EAHE system, focusing on cost-effective approaches to enhance its technical, economic, and environmental performance. The thermal performance and economic viability of the EAHE system hinge on the thermal characteristics of the surrounding soil. The EAHE model features a single pipe with dimensions of 0.5 meters in diameter, 1 centimeter in thickness, and 10 meters in length. These pipes are strategically placed at depths of 1 meter, 2 meters, 3 meters, and 4 meters below the ground's surface. To optimize heat exchange efficiency while minimizing pipe length, we propose using a secondary soil material with high thermal conductivity as a lining for the EAHE pipes. Our innovative approach carefully considers the economic and environmental aspects of various lining materials, resulting in optimal performance at a minimal cost. Extensive simulations and data analysis lead us to identify an ideal lining material, naturally available, environmentally friendly, and cost-effective, ensuring peak efficiency. Our investigation assesses the EAHE system's thermal performance for both summer cooling and winter heating, demonstrating its effectiveness across seasons. This research underscores the case for utilizing EAHE systems during winter and autumn for heating and during spring and summer for cooling. Our findings are supported by robust performance indicators, confirming the effectiveness of our approach

Influence of Density and Water Content on The Thermal Diffusivity of Wood Chips

The use of agro-industrial residues are currently experiencing an undeniable revival of interest in developing fully renewable insulation materials, that can be competitive in price and performance, in addition of low embodied energy. Among these vegetable waste materials; wood chips. These latter are light, compressible and very sensitive to water, due to their highly porous structure, which constantly modifies their thermal properties. The main objective of this study is to examine the influence of moisture content and density on the thermal diffusivity of wood chips, using the flash method. Four theoretical models were used to identify the thermal diffusivity. The results obtained show a decrease in thermal diffusivity with an increase in wood chips density. Furthermore, moisture content has an influence on thermal diffusivity. The experimental results show fluctuations with a slight decrease in thermal diffusivity with a maximum corresponding to a moisture content value Wm