Spectral light transmission measure of metal screens for glass\ud façades and assessment of their shading potential

摘要

Metal mesh grids and perforated screens are used in new and renovated buildings as an external second skin for the building\udenvelope; to enhance architecture design, to filter daylight and to reduce solar gains. Their effectiveness as shading devices\uddepends on their geometry, texture and application.\udIn the first part of the paper six types of shadings with similar transparencies, depending on geometry and openness factor of\udmetal mesh grid and perforated screen, were investigated. Integrating sphere measurements were collected to obtain spectral\udoptical properties of the shading devices. The optical properties were measured for incidence angles between normal and 60°with\uda step of 15°. The data collected were integrated to obtain visible and solar transmittance values in accordance with ISO 9050.\udIn the second part of the paper a parametric study on spacing and thread dimension of metal mesh grids was done using Window\ud6.2 models to evaluate their shading potential, defining annual different shading profiles depending on shading geometry, latitude\udand orientation.\udA conventional office unit with a curtain wall façade with a metal mesh grid shading system was modeled in TRNSYS to\udevaluate the solar gain profiles and their effects on the energy balance of the office unit, under different weather conditions.