In the past building roofs were either a light colored or a dark colored roof. The light colored or "cool roof" was supposed to reflect the sunlight beating down on the structure and keep the building cooler, lowering the energy bill. However, in the winter months the heat escaped which caused a rise in the energy bill. In contrast the dark roof trapped the heat in the summer raising the energy bill, while in the winter the heat was held in lowering the energy bill. In other words either way you were stuck with a high bill at some point. But now there is a end in sight to this dillema.
A Chemical Roof Coating From Recycled Waste Oil
At the 239th National Meeting of the American Chemical Society, (ACS), scientists described the development of the "Smart Roof" coating. In essence this discovery serves two purposes:
- It recyles used cooking oil from fast food restaurants
- It serves as a polymer coating for roofs that will help lower energy costs
A Smart Roof?
How does this amazing discovery work? Well the oil used has the ability to "read" a thermometer, in other words at a certain temperature it heats up or cools down according to a preset point that is tuned to the local atmosphere. In other words in summer time it would reflect the summer sun which would alleviate the build up of heat in the building and in the winter it would absorb the heat from the sun warming the building.
Ben Wen, PhD and leader of this research project as well as vice-president of United Environment & Energy LLC in Horseheads, N.Y. was qouted as saying; ""This is one of the most innovative and practical roofing coating materials developed to date. This bio-based intelligent roof coating, compared with a traditional cool roof, could reduce both heating and cooling costs as it responds to the external environment. It will help save fuel and electricity and reduce emissions of volatile organic compounds from petroleum-based roofing products. In addition, it will provide a new use for millions of gallons of waste oil after it is used to cook french fries and chicken nuggets."
Better than a White Roof
Although scientists have evidence that "white roofs", roofs painted white to reflect the summer sun, could reduce the effects of global warming, there is still the issue of the increased energy consumption in the winter months to maintain heating in these buildings.
The new "intelligent" coating may help end this issue. Tests on coated asphalt shingles showed that it could reduce roof temperatures by about 50 – 80 percent in warm weather. In cooler weather, the coating could increase roof temperatures up to 80 percent compared with the traditional cool roof. Wen and his collegues are able to "tune" the coating so that at specific environmental temperatures it changes from reflective to transmitive
The production of this coating processes waste cooking oil into a liquid polymer which hardens into a plastic after application. Although raw waste oil can retain an odor the polymer is virtually odorless, and can be produced in any shade depending on additives, it is also nonflammable and nontoxic and could be ready for commercial use in three years.
Wen was qouted as stating; "Even though the roof temperature is reduced or increased by a few degrees, depending on the outside temperature, this change could make a big difference in your energy bill."
It is important to understand that you should not simply coat your roof with waste cooking oil, it lacks the additives to convert it into a polymer and is a fire hazard for the building.