Analysis of the Effects of Soil Thermal Properties on the Performance of an Earth-Air Heat Exchanger

Resumo

Among the ways to obtain good thermo-energetic performance in buildings, passive air conditioning
stands out. These systems use the potential of the local climate and the characteristics of the building envelope to
promote thermal comfort for the occupants, using low energy costs, as is the case with Earth-Air Heat Exchangers
(EAHE). In this system, ambient air circulates through a pipe buried at a certain depth in the ground, causing it to
heat up or cool down, depending on weather conditions. These effects are possible due to the high thermal inertia
that keeps the soil at an almost constant temperature, at specific depths, even with high external temperature
amplitudes. In this context, the performance of EAHE depends directly on the thermal properties of the soil. Thus,
numerical simulations will be performed using the Ansys/Fluent software. The effects of the thermal properties of
different types of soils will be verified on the thermal performance of these exchangers. An EAHE prototype was
installed at the Federal University of Technology – Paraná (UTFPR) to validate the numerical model.