Study on Performance of Anisotropic Materials of Thermal Conductivity

Abstract

The advantage and shortcoming of anisotropic material of thermal conductivity using as building envelope were analyzed in this paper. The thermal performance of anisotropic material of thermal conductivity was presented by rotating the original rectangular axes so as to determine the principal axes and make the cross-derivative terms disappear. The results indicated that the heat flux vector is commonly not perpendicular to the isothermal surface in anisotropic material. Double skin facade has been successfully applied in many building designs. The application of laminated composite with anisotropic thermal conductivity in double skin envelope was proposed to avoid its disadvantage. The interior envelope in double skin system may be made of laminated glaze or other laminated materials. Basing on the combination of anisotropic material and double skin envelope, the indoor cooling and heating load decrease in summer and winter respectively while the anisotropic material was used as interior building envelope. Especially in summer, the effect of energy saving is obvious since the partial magnitude of conductive heat in the interior envelope could be brought out from the cavity by natural ventilation through it.