Energy Environment  
&
DIY Paint-On Coating Could Make  
Windows More Energy Efficient  
nergy leakage through windows  
costs building owners an esti-  
mated $50 billion annually.In an  
E
effort to curb those costs, the U.S. De-  
partment of Energy (DOE)’s Lawrence  
Berkeley National Laboratory (Berkeley  
Lab) has synthesized a potential solution.  
Researchers have developed a polymer  
heat-reflective coating that can be  
painted on at one-tenth the cost of other  
solutions,officials there say.  
There are retrofit window films on  
the market now that have spectral se-  
lectivity, but a professional contractor  
is needed to install them, a barrier for From left, Raymond Weitekamp, Arman Shehabi and Steve Selkowitz are using  
many building owners,”reads a post by the Berkeley Lab windows test lab to develop a paintable, heat-reflective  
Berkeley’s science writer Julie Chao.“A coating for low-cost, energy-efficient windows.  
low-cost option could significantly ex-  
pand adoption and result in potential  
For the ARPA-E award, Weitekamp is sun’s energy, reducing the amount of  
annual energy savings of 35 billion collaborating with Berkeley Lab’s Steve heat passing into a building, while still  
kilowatt-hours, reducing carbon diox- Selkowitz, a leading expert on building appearing clear to the eye.  
ide emissions by 24 billion kilograms science and window technologies, and  
per year,the equivalent of taking 5 mil- Arman Shehabi, an expert in analyzing simulation models and life cycle as-  
lion cars off the road.” energy use of buildings,to develop a cost- sessment models to understand how  
Shehabi will be developing building  
The coating will be a do-it-yourself competitive and scalable product. Their this technology would impact energy  
retrofit—at least that’s the vision, says target cost is $1.50 per square foot,which use in buildings and how energy sav-  
Cyclotron Road scientist Raymond they say is one-tenth the current market ings could be maximized. He’ll also be  
Weitekamp, who says it will do almost cost for“commercially-installed,energy- using certain models to look at things  
exactly what film does.  
The coating will selectively reflect the  
infrared solar energy back to the sky while reward projects,” Shehabi says. “The  
efficient retrofit window coatings.”  
“ARPA-E invests in high-risk, high- and a general payback period.  
“This was originally an exploratory  
such as manufacturing considerations  
allowing visible light to pass through, high reward in this project isn’t in the synthetic chemistry project,but having  
which will drastically improve the energy performance improvement. It’s trans- the deep windows and building expert-  
efficiency of windows,”he says.  
formative in how windows could be ise on the applied side here at Berkeley  
A team of Berkeley Lab scientists is retrofitted—it’s something you can do Lab,we thought,we can do this in a big-  
receiving part of a $3.95 million award yourself.The market need is very large, ger and better way,”Weitekamp says.  
from the DOE’s Advanced Research and there’s nothing low-cost out there  
briefly ...  
Projects Agency–Energy (ARPA-E) to that meets that need.”  
develop this product.  
One of the technical challenges re-  
Davidson, N.C.-based Ingersoll  
Rand was recognized by the U.S. En-  
vironmental Protection Agency dur-  
ing the Climate Leadership Awards.  
The company received an Organiza-  
tional Leadership Award for phasing  
out HCFCs and other refrigerants. s  
The Berkeley Lab technology relies on maining is to improve the reliability of  
a type of material called a bottlebrush the material,because as it stands,when  
polymer which,as its name suggests,has infrared light is strongly reflected, the  
one main rigid chain of molecules with visible light can be scattered or hazy.  
bristles coming off the sides.This allows When that’s achieved, it will allow the  
the liquid to be applied evenly.  
coating to reflect the majority of the  
34  
USGlass, Metal & Glazing | May 2016  
www.usglassmag.com