Double Glazings: Spectrophotometric Characterization for Facade Modules

Helenice M. Sacht

Luís Bragança

Manuela Almeida

Heriberto O. Nascimento

Rosana Caram

ABSTRACT: Glazing contributes significantly to heat transfer between outdoor and indoor spaces and these surfaces act directly on daylighting and thermal comfort. Based on these aspects, spectrophotometric characterization of double glazings was accomplished to study components for a modular facade system for the climate of Portugal. This study focused on results of spectrophotometric measurements of optical behavior in the different solar spectrum intervals ultraviolet, visible and near infrared, specifically transmittance of two types of double glazings. The first double glazing presents a single pane of green glass with a solar control foil and a single pane of a glass with an extremely low-emissivity foil; the second one presents a single pane of self-cleaning glass and a float clear annealed glass. Results show the percentage of transmission to spectrum intervals, which enabled the verification of the efficiency of the glazing in terms of daylighting and the correlation to thermal performance. These results generate subsides and indications for specification and adequate uses of transparent surfaces, and also complements the datasheets available from the manufactures.

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