A new model based on experimental results for the thermal characterization of bricks

The development of fast and reliable protocols to determine the characteristics of building materials is of importance in order to develop environmentally friendly houses with an efficient energy design. In this article heat flux evolution on different types of clay and concrete bricks has been studied using a guarded hot-plate. The studied bricks were purchased from local commercially available sources and included a solid face brick and a range of honeycombed and perforated bricks. From the data collected a new model to study heat flux is proposed. This model is based on the shape of the typical sigmoidal curves observed for the time dependent heat flux evolution. The model allows the calculation of the thermal resistance (R) and the heat flux in the steady-state (phi(infinity)). The model also calculates two new parameters, t(B) and tau(B). t(B) represents the time at which half phi(infinity) is attained. This parameter (t(B)) has additionally been found to be dependent on the thermal diffusivity and the geometric characteristics of the brick. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.