Night Vision Tech Detects Heat Leaks in Houses

1. The city flyover

On a cold, clear night in January 2011, the city of Coventry in the U.K. sent a plane flying over its 32 square miles of sleeping residents. The plane took infrared images of roofs throughout the city, measuring how much heat they were giving up to the frigid night air. The final images showed heat loss on roofs at a resolution of half a meter, allowing the city council to see which roofs were well and poorly insulated.

 Coventry, whose average January low temperature hovers around 20 degrees Fahrenheit, is especially worried about households that spend 10 percent or more of their income on electricity and gas, said David Shiner, principal housing officer in the Coventry City Council. The U.K. defines such households as living in "fuel poverty." One in four households in Coventry is fuel-poor, Shiner said, and some families end up choosing between basics such as food and heating. "When people are in that sort of fuel poverty, the impacts can be quite profound."

So the city council matched their infrared data with data about which households in the city rely on government assistance. They found over 18,000 households that were low-income, but leaking heat out their roofs. They mailed those houses offers of free loft insulation, paid for by taxes on the six major energy suppliers in the U.K. Six hundred and fifty-three houses responded and had new insulation installed. Loft insulation saves households about $300 a year, said Michael Checkley, sustainability manager for Coventry.

The council has handed over their data to the local branch of their national health service, which is matching the data with their own records on Coventry residents who might be especially vulnerable to cold, such as elderly people. They've also posted a map of the roofs online, so homeowners could look up their own houses by post code or address. 

 A few other city agencies in the U.K. have asked Shiner about performing their own thermal flyover, including one agency in the West Midlands region and one in London. The project cost about $30,000, Shiner told InnovationNewsDaily. They hope to check the roofs again in 2013.

2. The city drive-by

One group of researchers is working on a system that would check houses not by plane, but by car. Engineers at the Massachusetts Institute of Technology developed a low-resolution infrared camera that they strap onto the roof of a car and drive around the streets of Boston. The camera takes thermal images of the buildings they pass. Then a computer program the researchers developed stitches those images together to create a high-resolution image that can show details not at the half-meter level, like the Coventry project, but at the inch level. The new system can see "if you have a leaky door or a leaky window or a leaky sill," said Long Phan, a doctoral student who is working on the project. 

The drive-by thermal camera at work. CREDIT: Courtesy of Long Phan

The system can also directly translate heat to dollars. By gathering data about the local weather, the cost of materials at Home Depot and other sources, the camera's software can tell users how much they would save by installing insulation. "What we come up with is how much that is leak costing you," Phan told InnovationNewsDaily. The calculation is even region-specific. "If you live in the Northeast where it's cold in the winter, a leak will cost you a lot more than a leak in Florida."

Phan and his colleagues have created a startup, Eye-R Systems, to commercialize the camera. They've also won a Department of Defense contract to help the agency evaluate its buildings. 

Phan hopes that he can work with utilities companies in the future to provide people with heat-loss maps of their houses. "It may be included in [customers'] utility bill if they choose to do it," he said. The gas company could offer targeted incentives along with the infrared report, for example a rebate for better windows if that's where warmth is leaking away from a house. 

The prototype camera Phan and his research team built cost them about $100,000. Once mass-produced with a better-quality camera, it would probably cost even more, he said. 

3. The hand-held thermal flashlight

Why should thermal imaging cost thousands of dollars? One volunteer group is working on hand-held thermal imaging devices, shaped like flashlights, that people can make at home for about $40. "It can see the temperature of thing you're pointing at," said Jeffrey Warren, one of the group's founders. The flashlight then shines red, blue or somewhere in between, depending on the temperature it detects. The default flashlight shines red above 75 degrees Fahrenheit and blue below 60 degrees.

Users slowly pass the flashlight over the walls of a room while recording with time-lapse photography or a free application called GlowDoodle. The photography creates an image of the room's temperatures.

 Warren's group, The Public Laboratory for Open Technology and Science, is a nonprofit organization dedicated to developing affordable, do-it-yourself science tools. Warren said they're talking with advocacy groups that check low-income houses for insulation about using the flashlight. Warren also showed kids how to make the flashlight at a camp in Somerville, Mass., and one of the kids' parents want to use it to check houses they're interested in buying.  

People can find directions for creating the thermal flashlight on Public Laboratory's website. It requires an understanding of how to build circuits and enter computer code.  Public Laboratory members are considering mass-producing the circuit boards and giving them to people through the funding platform Kickstarter, where the lab already gives out kits for a balloon-based aerial mapping device.

You can follow InnovationNewsDaily staff writer Francie Diep on Twitter @franciediep. Follow InnovationNewsDaily on Twitter @News_Innovation, or on Facebook.