Impact of Earth-To-Air Exchanger on Heating and Cooling Energy Needs of a Residential Building in Benguerir, Morocco

Abstract

The purpose of this work is to design and investigate the effect of an Earth-to-Air Heat eXchanger (EAHX) on the thermal comfort conditions of a residential building in Benguerir, Morocco. The EAHX is designed throughout a parametric study in the context of the soil properties and the hot semi-arid climate of Benguerir, considering two of its significant parameters which are the pipe length and the burying depth. More than 120 combinations of these parameters are studied by carrying out more than 120 dynamic simulations using the well-validated TYPE 460 of TRNSYS software. The identification of the best combinations of the EAHX parameters is based on the maximum and the minimum EAHX exit air temperature for cooling and heating purpose respectively. Considering, the land availability around the house, it was found that the best EAHX parameters combination is constituted of 8 pipes of 51 m length and 0.15 m inner diameter buried at a depth of 4.5 m, operated at 3 m.s-1 air velocity. This system allows for 36% of the house's annual cooling load based on a set temperature of 26°C, while the system is not interesting for air heating.