Scientists Develop a Cool Concept: Send Heat from Buildings into Space

Friday, June 26th, 2015

Nerd alert!

Yes, we’re proud to say we’re big HVAC geeks here at Daffan Cooling & Heating. We love all things about ACs, heaters, heat exchangers, ductwork, insulation, thermodynamics … the list goes on and on.

So a radical idea for cooling buildings recently caught our eye.

A group of engineering researchers at Stanford University propose placing high-tech mirrors on rooftops to radiate heat from inside the building into space. Also, on clear days, the mirror can stave off incoming heat by reflecting sunlight.

To accomplish this, the researchers have invented a new coating material that interacts with visible and invisible light in a unique way, delivering a “one-two punch” to keep buildings cool.

For the first “punch,” material acts as a radiator, sending invisible infrared light–and its heat–away from a building. What’s mind-blowing is that the material is able to radiate the infrared energy at a precise frequency that lets it pass through the atmosphere without warming the air. The heat ends up in outer space.

“Think about it like having a window into space,” said electrical engineering Professor Shanhui Fan, who led the engineering group’s research project.

With the second “punch,” the material acts as a mirror, reflecting 97 percent of sunlight away from the building.

The engineers describe their concept as “photonic radiative cooling.” In their research with a prototype of the material, they found that the one-two punch of the mirror-like device makes it nearly 9 degrees cooler than surrounding air during the day.

So the coating material and cooling concept appears to have potential. The next steps for the researchers including figuring out an efficient way to transfer the heat from a building to the radiative coating. Also is the issue of production–the Stanford team believes the material can be manufactured at the size and scale needed for placement on large building rooftops.

Depending on how you look at it, this is hot–or cool–stuff. Want to learn more? Click on this link to the Stanford news release.