No one's home, but these smoke detectors are listening

The city of Louisville, Kentucky, turned to citizen scientists to solve the problem of vacant property fires.

Ashlee Clark Thompson Associate Editor
Ashlee spent time as a newspaper reporter, AmeriCorps VISTA and an employee at a healthcare company before she landed at CNET. She loves to eat, write and watch "Golden Girls" (preferably all three at the same time). The first two hobbies help her out as an appliance reviewer. The last one makes her an asset to trivia teams. Ashlee also created the blog, AshleeEats.com, where she writes about casual dining in Louisville, Kentucky.
Ashlee Clark Thompson
5 min read
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Watch this: City turns to hackers to quell house fires

The abandoned house next door to George and Gail Drummond threatens the home in which they've lived for more than two decades. The house, located in the West End of Louisville, Kentucky, has been empty for about 10 years, the Drummonds said. In that time, the couple has seen the house fall into disrepair. George Drummond has found drug paraphernalia in the back of the house. There's been at least one fire.

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The Drummonds live in the house to the left. The property on the right has been abandoned for about 10 years, the couple said.

Chris Monroe/CNET

"It would just break my heart if I came home and that side of my house was burned or my house was burned down," he said.

Fires that start in vacant properties are a problem to folks like the Drummonds and the city of Louisville. They often start in the middle of the night when neighbors are asleep, usually because of squatters who start fires for warmth in the winter or people doing illegal activities. By the time someone notices the fire, it's grown so large that there's a risk it will spread to neighboring homes. That's an even bigger danger in urban areas like the Drummonds' neighborhood, where the houses are close together, said Major Brian Meurer, Assistant Fire Marshall of the Louisville Fire Department.

Last year, 6 of the 39 vacant structure fires in the city spread to adjacent properties, which caused more than $992,000 worth of damage, he said.

"It's definitely a problem and a drain on resources," he said.

In 2015, the city of Louisville's Office of Performance Improvement & Innovation turned to civic hackers with a challenge: Use technology to solve the problem of vacant property fires. This led to the creation of the Completely Autonomous Solar-Powered Event Responder, aka CASPER -- a wireless device you put in vacant homes that listens for the sound of smoke detectors going off and sends text messages to let the city know there could be a fire.

Local government officials are used to turning to citizen scientists to find technology-driven ways to solve problems. In fact, Louisville is one of many cities around the world attempting to become a smart city, a place where citizens can tap into city data through devices and platforms that are a part of the Internet of Things -- the collection of seemingly normal household items like light bulbs and thermostats that connect to the internet and each other.

CASPER is a relatively low-key project -- it's not as cool as asking Amazon's smart speaker for the date of your next trash pickup or as flashy as connected light bulbs that tell you about the air quality in the city. But CASPER illustrates how technology and city government can work together to solve problems that impact you without much effort on your part.

"It's really not about vacant properties at all," said Nathan Armentrout, one of CASPER's creators. "It's about keeping the houses next door safe."

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The CASPER is made up of a solar panel, a cellular modem, a microphone and a battery.

Chris Monroe/CNET

The Office of Performance Improvement & Innovation realized that vacant property fires were a problem for the city when they looked at four years' worth of data about destructive fires. Of all the fires that spread to two or more properties during that time period, half of them began in a vacant home, said Ed Blayney, the innovation project manager for the city. And the city needed a solution that could address the issue on a large scale -- according to the Vacant and Public Property Administration, there are about 7,800 vacant properties in Louisville with code enforcement issues, along with more than 600 properties that the city owns.

"There's a real safety problem around this," said Grace Simrall, the city's chief of civic innovation.

One hackathon later, a group of hackers created CASPER, which is essentially a smoke detector detector. Here's how it works: The device contains a microphone, a 3G cellular modem and a solar panel and battery. The microphone listens for the sound of a smoke detector, which emits a unique frequency that CASPER is designed to identify. If the mic hears a smoke detector, it sends that information to the cloud, which in turn, sends out a text notification to designated people to let them know that there could be a fire in a home. CASPER only keeps a record of the sound it picks up if it thinks it hears a smoke detector. The unit costs about $150 to make, and plus a $10-per-month charge for the data plan for the cell modem.

"The design really centers around trying to be super-low maintenance and super-easy to work with," Armentrout said.

Smart smoke detectors keep an ear out in vacant homes

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To test CASPER, officials went into nine city-owned vacant properties in October and placed smoke detectors throughout the homes and mounted the solar-powered CASPERs in windows. So far, there haven't been any fires. But they've learned a few things:

  • The CASPER hasn't made any false alarms during testing. There was one close call -- a smoke detector that was in one of the test houses had a dying battery, which made the detector emit a sound that the CASPER picked up.
  • One of the biggest challenges with CASPER is finding the best spot to mount it so it has consistent sunlight.
  • Communication with neighbors and potential homeowners is important so they know what the city is trying to do. Someone put phonebook pages over one window in which the CASPER was mounted (Blayney said that the person might have been afraid the device was monitoring neighborhood activity). Another person bought one of the test houses, but threw the CASPER away before they realized what it was (there are now eight test houses).
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One of the biggest challenges in testing CASPER is to find the best window in which to mount the unit so the solar panel gets the most sun.

Chris Monroe/CNET

The pilot program runs through March. Then the city will decide how well CASPER works and if it's worthwhile to extend the program to more houses. Armentrout said he'd like to put CASPERs in 200 more homes after the initial testing ends.

"The more devices we can put inside these houses, the more coverage you have in the neighborhood," he said. "And that helps people feel safer and feel better about their living situation."

Armentrout said he'd like to keep developing CASPER to listen for other sounds such as broken glass or animal noises, so the system will send notifications to the appropriate city department. He'd also like to see this project develop into a business that could expand to bank-owned vacant properties and other cities.

Meurer said he sees the potential in CASPER, but would like to see it expand to commercial vacant properties and have a lower cost so more homes could have the protection.

"They're just cost prohibitive now," he said. Finding a way to make CASPERs less expensive "could be a way to allow more homes to have that protection."

The Drummonds are just happy to see the city take on a problem that threatens their own home.

"At least we know somebody's looking out for us and trying to do something," Gail Drummond said.