Special ‘blankets’ could help melt monstrous snowbanks more quickly
Giant, dirty piles of snow can clog up parking lots for weeks.
In the days after 2016’s Winter Storm Jonas buried the mid-Atlantic under two feet of snow, Jonathan Boreyko found himself searching in vain for a parking space on the Virginia Tech campus, where he teaches. Most of the spaces weren’t taken by cars, but by huge heaps of snow. “About a third of the spots were blocked by giant snow piles created by the snow plows,” he recalled. “These snowbanks can last for weeks.”
Long after the street plows have done their work, snowbanks often remain a problem. They line the sides of roads, making it impossible to park, or they barricade parked cars, making it impossible to get out. They obstruct crosswalks and cover athletic fields, the top floor of parking garages, and residential lawns and sidewalks. After a few days, if nothing is done, they also become dirty and unsightly.
Many snow-prone cities haul snow to disposal sites or use gas-powered heaters to melt it, methods that are labor intensive, time-consuming and expensive. Some places dump soot, salt or other products to speed melting, which can contaminate ground water and soil and, in the case of salt, burn dogs’ paws.
Fresh snow reflects most of the sunlight shining on it and sends much of the heat from those rays back into the sky. As a result, a big snowbank sometimes can take weeks to melt, even when the air temperature rises above freezing.
“I realized that snow melting is inefficient because ice is so reflective and wondered whether there was an easy way to make the snow more absorptive,” said Boreyko, an assistant professor in the department of biomechanical engineering and mechanics at Virginia Tech. “It probably also helps that I grew up in New Hampshire, where the snowbanks can be 15 feet tall, and the snow on the mountains can survive even into the summer months.”
That’s when the idea hit. He and his colleagues decided to create something that could swiftly melt snow without harming the environment and wouldn’t cost too much.
They came up with what they call the MeltMat, a thermally absorptive blanket made of an aluminum alloy and coated with either black enamel or black silicon-based spray paint, which readily absorbs sunlight. After testing it, they found that their invention absorbs three times more heat from the sun’s radiation as compared to the bare aluminum or uncovered snow left to melt on its own. Their study appears in the journal Langmuir.
Massive snowstorms are on the rise due to climate change. The frequency of extreme snow in the Eastern two-thirds of the country has increased dramatically during the past century. The latter half of the 20th Century saw about twice has many extreme snowstorms in this region as the first, according to the National Oceanic and Atmospheric Administration. These extreme storms are fueled by warmer-than-average ocean surface temperatures. That extra heat causes more water to evaporate, giving more ammunition to snowstorms.
“I am not a climate scientist, but it is my understanding that climate change is resulting in more intense snowstorms,” Boreyko said. “My friend lives in Boston, for example, and the snowstorms there have gotten so bad that people have to write ‘car here’ in the snow bank so that plows won’t accidentally hit cars hidden under monster snowbanks.”
The MeltMat is intended for regions and seasons where the air temperature is above freezing for part of the day. Otherwise, the melted water would refreeze. It should “work best in areas where the fallen snow gets good exposure to the sun and when it can get above freezing in the daytime,” he said. “So parking lots and athletic fields seem especially ideal since they receive sunlight all day long, whereas driveways may only receive the sun for a fraction of the day. Cities that are too northerly may not be appropriate during the peak winter months, because it may not get above freezing even after the snowstorm is over.”
For places where it can be effective, the MeltMat is environmentally friendly and quite inexpensive. “The only cost to our method is the fabrication of the device, which is glorified aluminum foil that is spray painted on one side, and the human cost of deploying and reclaiming the device before and after snow melting,” Boreyko said.
“In contrast, New York City spends $100 million per year on active hauling and heating methods for snow removal,” he added. “The Snow Dragon is a gas-powered heater that use 30 to 40 gallons an hour when melting a single snowbank. Compare that to just draping a large foil sheet over the same snowbank.”
The device potentially has value for several sectors, including governments, businesses and homes. “For homeowners, you could imagine rolling a yoga mat-shaped product over a driveway or sidewalk,” Boreyko said. “One major benefit is for those who are physically unable to shovel snow due to old age or a medical condition.”
“For cars, where there is too much snow to even get inside and defrost — sure, the MeltMat could be useful, but only if you weren’t in a hurry to leave,” he added.
The amount of melting time depends on the outside weather — the air temperature and amount of sun — as well as how thick the snow is. “But, as an example, the snow piles in the Virginia Tech parking lot usually take about ten days to completely melt, the blanket could reduce this to about three,” he said. “For cases where the snow pile is much smaller — for example, a driveway — you could imagine an example where a thin layer of bare snow would take two days to melt, but the blanket could melt it in a few hours within a single day.”
Boreyko is exploring licensing options with several companies to develop the product commercially. Because the device doesn’t hurt pavement or grass, he hopes one of the first purchases will be made by his own homeowners’ association.
“We think homeowners’ associations would like deploying MeltMats because it is very common that their shoveling and plowing accidentally damages the driveways and sidewalks of the homes,” said Boreyko, who lives in a Christiansburg, VA development. “In fact, this happened in my neighborhood and half the residents sued the homeowners’ association for driveway damage from plowing.”
Marlene Cimons writes for Nexus Media, a syndicated newswire covering climate, energy, policy, art and culture.