Could Blue Roof Coating Be More Energy-Efficient?

By Megan Treacy, TreeHugger

Dark-colored roofs are major heat absorbers, making buildings harder  to  cool, which requires more energy. For years now, the idea of white  roofs has been promoted as a way to cut building energy demand, but for  some,  darker-colored roofs are just more aesthetically pleasing.

For those people, researchers at Oregon  State University have found a solution — an environmentally-safe “cool blue”  pigment  that has darker tones, but reflects a huge chunk of infrared heat that   could be used in energy-saving coatings for buildings.

“This  pigment has infrared heat reflectivity of about 40 percent, which is   significantly higher than most blue pigments now being used,” said Mas   Subramanian, an OSU professor of chemistry who discovered the compound.

“The  more we discover about the pigment, the more interesting it gets. We   already knew it had advantages of being more durable, safe and fairly  easy to  produce. Now it also appears to be a new candidate for energy   efficiency.”

The compound, which has now received  patent approval, was discovered about  three years ago when OSU  scientists were studying materials for their  electrical properties.  Researchers noticed that some manganese compounds came  out of a 2,000  degree Fahrenheit oven transformed into a beautiful blue, which  they  figured out was due to an unusual “trigonal bipyramidal coordination” of   their molecules that changed when exposed to extreme heat. This  discovery led  them to develop the blue pigment.

The material is  now being considered for various commercial applications  that could see  it applied to roofs and walls of buildings to increase energy   efficiency. Widespread use of reflective coatings, like what this “cool  blue”  pigment could be used for, could reduce the heat island effect in  cities, lower  peak energy demand, and reduce air pollution due to lower  energy use and power  plant emissions.

“We’re seeking licensing  partners for this invention right now,” said Mary  Phillips, associate  director of the Office for Commercialization and Corporate  Development  at OSU. “We believe it can contribute to new energy efficiency  solutions  around the world.”