ANÁLISE DE MÉTODOS DE CÁLCULO PARA DETERMINAÇÃO DA TEMPERATURA DO SOLO EM SIMULAÇÕES COMPUTACIONAIS

Abstract

The floor contact of one-story buildings with the ground promotes heat exchanges that are relevant to the performance of the built environment. Therefore, ground temperature is an important factor in computational simulations and should be calculated whenever the floor of the environment is in contact with the ground. However, in some cases, setting this variable is relegated in the process of thermoenergetic performance analysis. In this context, the present article aims to analyze methods of defition of ground temperature for simulations of thermoenergetic performance of buildings under different envelope and climate conditions. The research method consisted of simulations for the calculation of the ground temperature of a singlefamily detached house through the Slab preprocessor and through the Ground Domain object (FiniteDifference and KusudaAchenbach models), both linked to EnergyPlus. It was considerated three construction systems (ceramic bricks, concrete wall and wood frame) and three Brazilian climates (Curitiba, São Paulo and Belém). Additionally, the performance of one of the bedrooms of the building for each method of calculating ground temperature was analyzed. The results showed some differences between the ground temperature generated by the Slab preprocessor and the Ground Domain object. It was observed that, in comparison with lower air temperatures, there is a relative similarity in the results, however, in the face of higher air temperatures, the difference between the two tools is significant. Comparing Slab and Ground Domain, differences in the average monthly ground temperature of up to 1.78 °C, 2.14 °C and 2.94 °C were obtained for Curitiba, São Paulo and Belém respectively. On the other hand, when comparing only the results by the calculation models of the Ground Domain, there was minimum difference in all cases: mean annual variation of up to 0.14 °C, 0.10 °C and 0.25 °C for Curitiba, São Paulo and Belém. In addition, no major variations in soil temperature were observed when only the construction systems were switched. In relation to the influence on the performance of the building, it was observed that there are significant differences in the response of the built environment in most cases, as the method of defining the ground temperature changes. There were differences of up to 49.71%, 33.92% and 27.91% in the CDH indicator for Curitiba, São Paulo and Belém, respectively. Finally, in general, it was concluded the relevance of the correct definition of the ground temperature in computational simulations.