AMHERST, Mass. — Researchers at the University of Massachusetts Amherst recently unveiled a tool to combat climate change, fossil-fuel dependency, skyrocketing home-heating bills and gentrification all at once—a simple fabric treated with a special photothermal dye that, when placed on outside walls, can help keep a home 8.64ºF warmer over the course of a day.
"Sometimes, a simple solution works best," says Trisha Andrew , professor of chemistry at UMass Amherst, and one of the paper's senior authors, along with Carolina Aragón , associate professor of landscape architecture, and Ho-Sung Kim , senior lecturer in building and construction technology.
"When you're cold, you put on a sweater," says Aragón, "so we started thinking: what would you do if you're a building?"
Heating buildings is a huge driver of fossil-fuel consumption, greenhouse gas emissions and energy insecurity. Over 33 million homeowners in the U.S. report trouble keeping their houses warm, and more than 24 million people—often renters—report skipping food or rationing energy in order to pay for heat. Meanwhile, according to the U.S. Energy Information Administration, residential and commercial buildings account for 39.1% of the primary energy used in the U.S. Reducing heating costs also translates into an enormous reduction in CO2 emissions.
The typical way to address an inefficient home is to tighten it up: new windows and doors, more and better insulation, etc. But if you're a renter, these options aren't necessarily open to you. Worse is the phenomenon of "reno-viction," where a landlord upgrades their property and then raises rents beyond what's affordable for their current tenants. "Too many people have to choose whether they heat or eat," says Aragón.
But what if keeping a house snug were as easy and affordable as putting on a sweater?
Andrew, among whose specialties includes inventing high-tech fabrics that can mimic animals adapted to extreme cold—like polar bears —and Aragón, who has long worked at the community scale to tell the story of climate change , teamed with Kim, who is an expert in modeling architectural designs for their energy usage.
The team initially thought of a building blanket, but ultimately what they designed and tested looks much more like jewelry: a series of removable tiles or panels that can be hung on any surface which not only conduct the sun's warmth but insulate the building.
The key is a special photothermal dye that Andrew invented. "We can put this dye on anything," Andrew says. "It doesn't have to be on an expensive fabric. We chose to test it on umbrella fabric—something that was rugged and robust but still affordable."
When they modelled their design, the results were eye-popping.
"We saw up to a 15% decrease in energy costs for a residential building in a northern climate, like Massachusetts," says Andrew, "and up to 23% reduction in a large, 16-story apartment building."
By comparison, a well-done traditional home renovation might yield a 2% reduction in energy costs.
These panels could even be sold as do-it-yourself projects that any renter could complete. The team imagines a scenario where people head to their local hardware store, buy a roll of the fabric and a few 2x4s and, in an afternoon, have a cheap and effective way of helping to heat their homes.
"Because the heart of this technology is a dye, we can use it to make panels that are beautiful and blend in with the specific culture and aesthetics of an area," says Aragón. "It's important to get the architectural and aesthetic part of this right, in addition to the science."
But before consumers rush out to ask for the miracle fabric, the team needs to conduct additional, real-world testing. Though they've proven the concept in the lab, they need more data and field tests with life-sized prototypes.
"This could have an enormously beneficial societal impact," says Andrew, and Aragón agrees: "there's a role for anything that is empowering at the individual scale."
The research appears in the journal ACS Applied Engineering Materials .
