Numerical Investigation Of Heat Transfer in a Multi-Layer Wall Used in Brazilian Buildings

Abstract

This paper investigates thermal walls behavior as elements of buildings and low-consumption energy residences. The problem is formulate based on the transient and unidimensional model, and numerically solved using the finite volumes method to discretize space and the implicit formulation to discretize time. Numerical tests were realized to optimize the mesh. Three different materials, heat transfer coefficient and color incorporation were tested in each wall layer A and B. The influence of these variations in the internal wall was calculated for each case. It was found that the best material for A and B walls are plaster mortar and common brick, respectively. This is a result of the inverse correlation between thermal resistance and the heat transfer rate. For a lower temperature in the external and internal walls, the thickness ratio for the external wall was  < 0.5 and for the inner wall was  > 0.5. The best value of absorptivity was 0.156 and the external heat transfer coefficient was variated to increase heat change. With all these parameters analyzed, it was possible to decrease significantly the heat transfer to the inner space and enhance the thermal comfort.

Thermal Analysis of Different Configurations for Building Insulation Systems With Actual Materials Using Real Solar Radiation and Temperature Data

“…The external temperature used varied in each simulation where the internal temperature was fixed in 20ºC. The external and internal convective coefficients were 28W/m 2 .k e 6W/m 2 .k, respectively, according to Dias (2018).…”