Experimental Measurments of Thermal Properties for Mexican Building Materials to Simulate Thermal Behavior to Save Energy

Abstract

One of the main factors that determine the reliability of building’s thermal design is the values of thermal and heat transfer properties used during this process. In order to optimizing such thermal design process, there is little information available of the most utilized building materials in Mexico; hence, some measurements were carried out. We present thermal conductivity experimental results for: red brick, tepetate, adobe and concrete. Furthermore, experimental data of convective heat transfer coefficients are reported on: red brick, tepetate, adobe and concrete walls.

Kondratyev methodology was used for thermal conductivity estimations. Kondratyev methodology is based on the cooling off of bodies in regular state analysis. Thermal conductivity values were: red brick k_L = 0.906 W/mC, tepetate k_T = 0.648 W/mC, adobe k_A = 0.570 W/mC, and concrete k_C = 1.918 W/mC. Red brick, tepetate, adobe and concrete test walls of 0.46x0.56 and 0.06 m thick, were manufactured, as well as a prototype of testing for mounting the walls, in order to evaluate their convective heat transfer coefficients. Measurements were carried out at the Institute of Engineering-UNAM Wind-Tunnel, for an air velocities interval of 2–10 m/s. Reported values for convective coefficients fluctuate on 16–134 W/m² °C, depending on material and position wall, as well as air velocity.