An Investigation of Transient, Two-Dimensional Coupled Heat and Moisture Flow in the Soil Surrounding a Basement Wall

A two-dimensional finite difference numerical model has been developed to study coupled soil heat and moisture flow around an earth-sheltered construction. Simulations of a basement wall backfilled with a sand and a clay loam were performed. For the sandy soil, a 9% greater wall heat loss during the winter and an increase of over 40% in summer heat gain were observed when the coupling was modelled. The principle mechanism for the greater heat flow was the energy transported by the moisture flow from the ground surface. For the clayey soil, there was no difference between the coupled and uncoupled results.