Imagine if the windows of your home didn’t transmit heat. They’d keep the heat indoors in winter and outdoors on a hot summer’s day. Your heating and cooling bills would go down; your energy consumption and carbon emissions would drop; and you’d still be comfortable all year ’round.

AeroShield, a startup spun out of MIT, is poised to start manufacturing such windows. Building operations make up 36% of global carbon dioxide emissions, and today’s windows are a big contributor to energy inefficiency in buildings.

To improve building efficiency, AeroShield has developed a window technology that promises to reduce heat loss by up to 65%, significantly reducing energy use and carbon emissions in buildings, and the company just announced the opening of a new facility to manufacture its breakthrough energy-efficient windows. 

At an event marking the opening of AeroShield's new pilot manufacturing facility in Waltham, Massachusetts, Aaron Baskerville-Bridges, co-founder and vice president of operations, shows an AeroShield prototype window with the ability to cut energy losses in half. Photo courtesy of AeroShield.

“Our mission is to decarbonise the built environment,” says Elise Strobach SM ’17, PhD ’20, co-founder and CEO of AeroShield.

“The availability of affordable, thermally insulating windows will help us achieve that goal while also reducing a homeowner’s heating and cooling bills.” According to the US Department of Energy, for most homeowners, 30% of that bill results from window inefficiencies.

Technology development 

Research on AeroShield’s window technology began a decade ago in the MIT lab of Evelyn Wang, Ford Professor of Engineering, now on leave to serve as director of the Advanced Research Projects Agency-Energy (ARPA-E). In late 2014, the MIT team received funding from ARPA-E, and other sponsors followed, including the MIT Energy Initiative through the MIT Tata Center for Technology and Design in 2016.

The work focused on aerogels, remarkable materials that are ultra-porous, lighter than a marshmallow, strong enough to support a brick, and an unparalleled barrier to heat flow. Aerogels were invented in the 1930s and used by Nasa and others as thermal insulation.

The team at MIT saw the potential for incorporating aerogel sheets into windows to keep heat from escaping or entering buildings. But there was one problem: nobody had been able to make aerogels transparent.

An aerogel is made of transparent, loosely connected nanoscale silica particles and is 95% air. But an aerogel sheet isn’t transparent because light travelling through it gets scattered by the silica particles.

After five years of theoretical and experimental work, the research team determined that the key to transparency was having the silica particles both small and uniform in size. This allows light to pass directly through, so the aerogel becomes transparent. Indeed, as long as the particle size is small and uniform, increasing the thickness of an aerogel sheet to achieve greater thermal insulation won’t make it less clear.

Teams in the MIT lab looked at various applications for their super-insulating, transparent aerogels. Some focused on improving solar thermal collectors by making the systems more efficient and less expensive. But to Strobach, increasing the thermal efficiency of windows looked especially promising and potentially significant as a means of reducing climate change.

The researchers determined that aerogel sheets could be inserted into the gap in double-pane windows, making them more than twice as insulating.

The windows could then be manufactured on existing production lines with minor changes, and the resulting windows would be affordable and as wide-ranging in style as the window options available today. Best of all, once purchased and installed, the windows would reduce electricity bills, energy use, and carbon emissions.

The impact on energy use in buildings could be considerable. “If we only consider winter, windows in the United States lose enough energy to power over 50 million homes,” says Strobach.

“That wasted energy generates about 350 million tonnes of carbon dioxide – more than is emitted by 76 million cars.” Super-insulating windows could help home and building owners reduce carbon dioxide emissions by gigatons while saving billions in heating and cooling costs.

The AeroShield story

In 2019, Strobach and her MIT colleagues – Aaron Baskerville-Bridges MBA ’20, SM ’20 and Kyle Wilke PhD ’19 – co-founded AeroShield to further develop and commercialise their aerogel-based technology for windows and other applications. And in the subsequent five years, their hard work has attracted attention, recently leading to two major accomplishments. 

In the new Waltham facility, Zach Goodman, AeroShield's lead process engineer, fabricates aerogels in the first step of the manufacturing process. Photo courtesy of AeroShield.

In spring 2024, the company announced the opening of its new pilot manufacturing facility in Waltham, Massachusetts, where the team will be producing, testing, and certifying their first full-size windows and patio doors for initial product launch.

The 12,000-sq-ft facility will significantly expand the company’s capabilities, with cutting-edge aerogel R&D labs, manufacturing equipment, assembly lines, and testing equipment.

Says Strobach: “Our pilot facility will supply window and door manufacturers as we launch our first products and will also serve as our R&D headquarters as we develop the next generation of energy-efficient products using transparent aerogels.”

Also in spring 2024, AeroShield received a $14.5m award from ARPA-E’s “Seeding Critical Advances for Leading Energy technologies with Untapped Potential” (SCALEUP) program, which provides new funding to previous ARPA-E awardees that have “demonstrated a viable path to market”. That funding will enable the company to expand its production capacity to tens of thousands, or even hundreds of thousands, of units per year.

Strobach also cites two less-obvious benefits of the SCALEUP award.

First, the funding is enabling the company to move more quickly on the scale-up phase of their technology development. “We know from our fundamental studies and lab experiments that we can make large-area aerogel sheets that could go in an entry or patio door,” says Elise.

"The SCALEUP award allows us to go straight for that vision. We don’t have to do all the incremental sizes of aerogels to prove that we can make a big one. The award provides capital for us to buy the big equipment to make the big aerogel.”

Second, the SCALEUP award confirms the viability of the company to other potential investors and collaborators. Indeed, AeroShield recently announced $5m of additional funding from existing investors Massachusetts Clean Energy Center and MassVentures, as well as new investor MassMutual Ventures. Strobach notes that the company now has investor, engineering, and customer partners.

She stresses the importance of partners in achieving AeroShield’s mission: “We know that what we’ve got from a fundamental perspective can change the industry.

“Now we want to go out and do it. With the right partners and at the right pace, we may actually be able to increase the energy efficiency of our buildings early enough to help make a real dent in climate change.”