Investigating the thermal behavior of double-skin perforated sheet façades: Part A: Model characterization and validation procedure

Publication date: December 2014
Source:Building and Environment, Volume 82
Author(s): Jesús M. Blanco , Pedro Arriaga , Eduardo Rojí , Jesús Cuadrado
New materials with external shading systems are mainly implemented on building façades to improve energy efficiency, but also to add a distinctive appearance. The double-skin perforated sheet-metal façade, an enclosure composed of sheet metal, air chambers and glass, is an example of this tendency in modern building design. The aim of this research is to study the thermal behavior of the façade taking into account several physical parameters such as, perforation rates, colors and materials, as well as the influence of wind penetration. The study also quantifies the improvements in terms of energy savings that different configurations of these parameters can bring to the building as a whole. First of all, a theoretical model was built in Matlab^® based on an energy balance of these types of enclosure. The experimental process for validation purposes consisted of monitoring metallic sheets within a range of 0–35% (perforation rates), black-white (colors) and galvanized steel-aluminum (materials) in a large-scale test campaign. Excellent agreement was achieved between the outputs from the above-mentioned numerical model and the test campaign, sufficient for its validation. The behavior of different configurations will be described in a further paper, addressing their influence on cooling, heating and lighting loads in the building, with an Energyplus^® model, which will be also validated with our theoretical model. Finally, additional parameters such as air-space width and location in the various climate zones defined for Spain will be carefully studied, for the optimization of design sustainability.