Thermal transmittance comparison between multilayer walls made from hollow fired clay and plaster-granular cork bricks using electrical analogy

In this work a comparative study of thermal transmittance between different multilayer walls is examined numerically using the so called Combined Method recommended in the Moroccan standard NM EN ISO 6946/2007. For this purpose a special script was written in Mathematica based on the electrical analogy and where all the thermal transfers occurring across the brick were considered. Tree configurations with and without air gap of 7 cm were compared. The first configuration, concerns walls made of cement render, cement mortar and tree sizes of hollow clay fired bricks (3, 8 and 12 cavities). In the second one, bricks were substituted with those prepared with plaster and granular cork mixes. Finally, in this second case, plaster-granular cork was used instead of cement render. In addition, the compliance with the Moroccan Thermal Regulation of Construction (MTRC) was examined. Results show that in the third configuration, double walls (with air gap) consisting of 8 or 12 cavities bricks are in accordance with all Moroccan climatic zones, leading to overall heat transfer reduction up to 51%.