Investigating the impact of earth tubes in an Earthship

Abstract

This paper presents a sensitivity analysis that explores the impact of design and operational factors on the performance of ‘earth tubes’ as a ‘passive’ cooling and heating strategy built into an Earthship dwelling located in South Australia. Earth tubes are pipes buried underground acting as heat exchangers to deliver fresh air to the internal spaces, which is cooled in summer and warmed in winter. The results show that the air flow and temperature in the earth tubes was sensitive to how the dwelling was being operated. Through simulations, the ideal scenarios of operating the dwelling in summer and winter in this location as well as in the climate where the Earthship concept was invented, i.e. Taos, New Mexico, are reported. Lessons learned from the study will help those who consider implementing earth tubes in their buildings.