Transient Heat Transfer at the Building-Soil Boundary

• Main Author: Dan CONSTANTINESCU
• Format: Article
• Language: English
• Published: National R&D Institute URBAN-INCERC, INCERC Bucharest Branch 2010-07-01
• Series: Constructii: Journal of Civil Engineering Research
• Subjects: conform transformation; virtual outdoor temperature; similitude criteria; hybrid mathematical model; boundary conditions; homogeneous and non-homogeneous environment
• Online Access: http://constructii.incerc2004.ro/Archive/2010-2/Art4-2-2010.pdf
• ISSN: 1221-2709; 2247-0328

The thermal flow transferred through the soil represents an important rate of the thermal flow dissipated to the outside by the buildings, mainly by the low ones. The buildings architectural solutions associated to the structural solutions, meant to carry out buildings with a low energy consumption used by the thermal utilities (heating / cooling) emphasize the impact of the building – soil boundary on the building thermal response. This article presents a hybrid calculation model of the soil thermal response to the indoor and outdoor random thermal loads, based on the combining the model specific to the steady-state solution by the conforming transformations method used in the case of the previously mentioned boundary and the Unitary Thermal Response (RTU) method specific to the impulse thermokinetics used in the case of virtual similar environments operating as a model, which substitutes the real environment (soil). The article also presents the results of the experiments performed on the CE INCERC Bucharest experimental building in the cold seasons 2003 and 2004. The deviations between the thermal flow experimental values and those theoretically determined by the INVAR software, ranging between 2.48 % and 5.45 % certify the proposed calculation model. The practical use of the calculation model is meant for the boundaries between the building and soil in several variants; it is included as a calculation method in the Romanian EPB (building energy performance) calculation method, Mc 001 / 1-2006.