The influence of glass and view on users’ thermal perception

Abstract

Glass is a key element in the daylighting design, whose quality is essential to the well-being of building users. Several reasons influence the choice of glass, such as its luminous and thermal performance. However, the glass’ selectivity modifies the appearance of light, impacting not only the visual perception, but also the thermal perception of the environment. Thus, this work evaluated the influence of glasses with different spectral selectivity’s and exterior view on the occupant’s thermal perception of a conditioned space. For that, a field study was carried out with 48 volunteers in a walk-in climatic chamber. The volunteers were divided and allocated into two positions, one with and the other without exterior view. Then, they were exposed to 3 types of glass under clear, partially cloudy and overcast conditions. Environmental thermal variables were measured, and thermal perception questionnaires were applied, and later compared to the calculated PMV. Results were analyzed using box plot graphs and ANOVA analyses. It was concluded that the thermal evaluations of the occupants, as well as the questionnaire application moment, are independent of exterior view and of changes in the glass spectral selectivity. Though, the exterior view maximizes the effect of the sky type on the user's thermal perception, while in the absence of the exterior view, the effect of the spectral composition of the sky is only perceived when combined with the selectivity of the glass.