The use of renewable energy sources to improve the thermal conditions of built environments and hence decreasing the consumption of conventional energy is an important aspect to design a sustainable building. Within this context, it is possible to harness the solar energy that reaches the Earth's surface and is stored by the soil as thermal energy. To do so, the Earth-Air Heat Exchanger (EAHE) device can be employed, consisting of a buried duct through which the external ambient air is insufflated. The flowing air exchanges heat with surround soil, and leaves the device with a milder temperature compared to its input temperature. The main goal of this work was to present a new computational modeling to predict the thermal behavior of EAHE. This new numerical model has the advantage of needing a lower computational effort, allowing the study about the influence of operational and constructive parameters, as well as, the application of geometric optimization methods in EAHE. A case study was developed where influence of the installation depth in the thermal potential of an EAHE was investigated. The results are in agreement with those found in literature; however they were obtained with a reduction in processing time of almost 45%. (C) 2013 Elsevier B.V. All rights reserved.