Thermal effectiveness of low emissivity coatings in hollow bricks: a numerical analysis for different cavity concentration

This paper presents the results of a numerical study concerning the investigation of the improvement of the overall thermal performance of masonry through the adoption of low emissivity coatings applied on hollow bricks cavity surfaces. Main aims of the research were, on one hand, to identify the optimal cavities concentration and, on the other hand, to assess the effectiveness of treatments with low emissivity coatings for different brick geometries and different emissivity of the coating materials. A comparison has been made among standard bricks, bricks with low emissivity coatings and bricks with insulation filling materials. Results shown that the optimal cavity size value is a function of the coating emissivity and thermal conductivity of the brick and that the adoption of Low_E coatings, for certain configurations, could reveal a more effective strategy in comparison with the insertion of insulation filling materials.