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EFFECT OF INTERNAL SKIN-PANELS METAL FRAMEWORK IN THE VENTILATED FAÇADES INSULATION
José Antonio Entrenas, José Ramón Jiménez
Keywords: Heat transfer, Thermal Bridge, Ventilated façade, Metal framework, Building simulation. 1. Introduction
To reduce buildings’ energy demand, the façade is the architectural element that has received more attention in the building sector. Ventilated façades have significantly evolved in recent years for new construction and renovation of buildings. A ventilated double façade is a conventional single façade doubled by a second façade, either inside or outside. Each of these façades is commonly called a skin. A ventilated cavity is located between these two skins (Loncour et at., 2004). The external skin incorporates the exterior coating elements, which are generally glazed, although they can be metallic, ceramic or made from stone. The ventilation of the cavity can be natural, fan- supported or mechanical. The internal skin can be a conventional façade built with traditional masonry or new building materials, such as industrial panels.
The industrial panels used as internal skins are an advanced dry lining system formed by cement board outdoor panels and accessories for exterior finishing, a metal or timber framework, insulation materials, joint compounds and interior finishing options, such as gypsum boards. The use of these panels in ventilated façades allow builders to satisfy the growing demands of new technical codes to meet the sustainability criteria (Blázquez, 2012).
The goal of this study is to determine the effect of a metallic substructure supporting the internal skin-panels in the ventilated façades insulation by numerical simulation. The metallic profiles of the framework are the elements with higher thermal conductivity; therefore, these elements have a notably unfavorable influence on the equivalent thermal conductivity value of the façade. The spacings and thicknesses of the profiles depend on the actions on the façade; however, recommendations are given concerning the use of metallic profiles to save energy.
2. Materials and methods
A commercial ventilated façade system is used to simulate the thermal conductivity. Fig. 1 shows the analyzed model, where the boundary conditions and materials are represented by a color code.
The simulations were performed on two variations of panels with different insulation material thicknesses (60 mm and 80 mm), and two different profile spacings (400 mm and 600 mm) and thicknesses (1 mm and 2 mm) are used.
New Trends in Green Construction
Fig. 1 Calculation model (Software BISCO)
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