Análise da viabilidade do uso de garrafas PET como artifício para provimento de luz natural zenital em interiores: ensaios em protótipo

Abstract

The issue of sustainability has been increasingly discussed in the construction sector towards greater balance between the natural and the built environment. Since PET is a product with a high participation in urban waste disposal, its use as an alternative to artificial lighting could provide greater sustainability in civil construction whilst saving energy. Furthermore Brazil has a privileged geographical location, with a large part of its territory lying around the Equator, which has high levels of solar radiation. Thus, this experiment intended to examine the performance of lamps built with PET bottles in different configurations, considering different seasons and latitude. Results indicate the feasibility of adopting PET-based ceiling bulbs as zenithal lighting during daytime. Higher efficiency was observed during solar peak hours, and when closer to equatorial locations. Measurements simulating winter months showed very similar results to a fluorescent lamp (between 8 am and 4 pm); in other seasons, indoor illuminance was even higher. It should be stressed, however, that the study was conducted under clear sky and, as other previous studies show, the effectiveness of this alternative ceiling lighting is lower on cloudy or rainy weather. Therefore, the combination of PET-based and conventional lamps (in particular, LED bulbs) is presented as a good alternative.