Not all ‘green’ roofs are green
An MIT student demonstrates the heat-sensitive color-changing property of the Thermelon roofing tile.
MIT students have developed a roofing tile that saves energy and heating and cooling costs by changing color depending on temperature. The tile turns white to reflect heat during the summer and becomes transparent during cool months, revealing a heat-absorbing black backing. While traditional roofing material is black, global climate experts (including US Energy Secretary Steven Chu) have been advocating for the painting of flat roofs white as a means of offsetting carbon emissions. The new roofing tile, dubbed Thermeleon (as in ‘thermal chameleon’), uses a phase-changing polymer gel to optimize thermal benefits in all seasons: when the temperature is high, the tile reflects 80% of the incident light, whereas when temperatures are cool, the roofing material absorbs 70% of the sun’s energy.
(via Treehugger and MIT News)
