For ages, people have been suffering from cold in the winter and from being too hot in the summer. Have you ever observed the Greek houses, and, generally, the Mediterranean ones? They’re all painted in white, just because white reflects heat and makes the home bearable to live in, because there the air is always warm and the days are almost always sunny.
Ok, but what do you do in the temperate areas of the world, where it’s hot during the summer and very cold during the winter? The same white roofs that kept your home cooler in the summer would now also keep you cooler during the winter. Bingo! You’d need black roofs to absorb the heat, not white.
Even the U.S. Secretary of State, Steven Chu, got involved into this discussion, as many proposed turning all roofs white to preserve a lot of electricity used in air conditioning systems.
While attending a competition for teams of MIT students, Making and Designing Materials Engineering Contest (MADMEC), a team of students and fresh-graduates have shown an invention that could turn the old roof tiles into chameleon-like tiles, turning from black to white and vice-versa as temperatures get low, respectively high.
The team of MIT students called their invention “Thermeleon”, and, according to Steven Chu, turning the roofs from all around the world white during the summer time would save as much greenhouse gas in 20 years as the entire world would produce in a year.
So, how did these students discover the technology and how does it work? At first, they say they didn’t follow this route of making the tiles, as they have been pursuing to develop a color-shifting roof tile using a system of mixed fluids, a dark one and a light one, whose density would have changed with temperature, but found it very complicated to build and the cost too high.
Instead, they jumped into another approach, by using a common commercial polymer in a water solution. The solution is encapsulated between layers of glass and plastic, in the original prototype, in their first version, and between flexible plastic layers in their latest version, with a dark layer at the back. The principle is apparently simple: when it’s hot outside, the polymer on the top turns into white, and when the temperatures goes below a certain threshold, the polymer liquifies itself, allowing the light to pass and hit the black surface from behind it, and collect the heat.
Keeping into account that black roofs reflect only about 30% of the light hitting them, and white ones reflect 80%, you’ll have to admit this invention could catch in all the parts of the world, as they provide excellent savings of electricity.
The students don’t want to stop here: their future aim is to build a micro-encapsulated polymer solution, that could be inserted into certain paints that could be applied to any roof, and the user wouldn’t have to change the old tiles to get the energy efficiency he needs during the extreme seasons.
The Thermeleon still has a long way from being produced commercially, but frankly, I already see it on the stores’ shelves in about five years without any problem. What do you think? Would you buy this product?
Question: What if it snows?