Jonathan Sprinkle, Susan Lysecky and their research team have developed a heating and cooling thermostat that enables homeowners to decide temperatures based on their budgets. The cost-limited thermostat means no surprises when the electric bill lands in the mailbox, at least not for energy used to cool and heat a home, which typically accounts for more than half of a homeowner’s utility bill, according to the U.S Department of Energy.
“Most people just set their thermostat temperature in the desired range then get a bill at the end of the month with no understanding of how they correlate,” said Sprinkle, adding that here in Tucson, where summertime sees most days above 100 degrees Fahrenheit, it is not uncommon for homeowners to pay $250 to $300 or more a month for electricity. Sprinkle, an assistant professor, was a graduate assistant at Vanderbilt University and postdoctoral researcher at the University of California-Berkeley before joining the UA department of electrical and computer engineering in 2007.
The team is focusing for now on heating and cooling because they use the largest portion of electric power in U.S. homes. Home energy accounted for 35 percent of all energy consumed in the United States last year, and 31 percent of that was estimated to come from heating, ventilation, and air conditioning. However, they are looking toward eventually applying the cost-limiting technology to smart energy management of the whole home.
How the Cost-Limiting Thermostat Works
The new cost-limited thermostat provides real-time feedback on temperature-cost correlation and puts consumers in control of balancing their comfort and budget. When the temperature schedule or monthly budget is changed, the thermostat immediately displays how one affects the other.
“They can trade off the costs of keeping a home cool or warm depending on how comfortable they want to be,” said Lysecky, an expert in design automation and interface design who joined the department as an assistant professor in 2006 after earning her PhD in computer science from the University of California-Riverside.
The technology behind the cost-limiting thermostat involves establishing customized home model and prediction algorithms based on continually updated environmental data inside and outside the home, explained Lysecky. For example, programmed into the thermostat is information on what temperatures residents prefer to keep the home during different times of the day, week, month, and year. The technology monitors the weather outside and learns temperature-related characteristics of the home itself, and over time it determines how long the heating or air-conditioning unit would have to run to keep the house at a particular temperature on a given afternoon or evening.
“Then, it advises the user: To get the best temperature for your dollar, this would be the daily schedule,” said Sprinkle.
Out of the Lab and Into the World
NSF Innovation Corps, or I-Corps, was instrumental in helping the team fine-tune their idea and assess market viability of the cost-limited thermostat. I-Corps is an intensive, six-month, online and onsite entrepreneurial training program that helps move select, NSF-supported, basic academic research projects toward commercialization.
Out of more than 300 applicants, 56 teams were chosen to participate in last summer’s course and split into two groups. In their I-Corps group of 27, Sprinkle and Lysecky’s research team won “Best Team” honors during an awards ceremony in July at NSF host site University of Michigan- Ann Arbor.
Born of the NSF experience was Sprinkle and Lysecky’s startup company Acomni, with partners Xiao Qin and Manny Teran. Xiao Qin is a UA electrical and computer engineering graduate student who specializes in embedded hardware and sensor networked systems, and Manny Teran is a UA aerospace and mechanical engineering alumnus and successful Tucson entrepreneur.
As part of the I-Corps program, the four conducted more than 100 interviews of potential customers. The interviews helped shape the thermostat prototype. While some survey participants said comfort, at any cost, was the most important factor, a majority felt that they were paying too much for electricity and wanted to be able to balance cost and temperature. Perhaps most importantly, they all wanted to be able to see how changing either the temperature or the budget affected the other. They wanted to be in control.
“Originally, the idea was to have a thermostat that showed dollars instead of degrees Fahrenheit,” said Sprinkle, an expert in industrial control technology and embedded and autonomous systems. “Once we started talking to people, we realized we needed to show temperature and dollars and how they correlate.”
Beyond the Homeowner
The cost-limited thermostat technology has the potential to reach beyond the homeowner’s pocketbook. As Sprinkle points out, becoming aware of energy consumption is the first step toward using energy more efficiently. In the grand scheme, more efficient electric power usage translates into lower emissions from fossil fuels being burned to generate electricity and heat, and that brings society one step closer to environmental sustainability.
The company’s ultimate goal is getting people to be more energy efficient, Sprinkle said. However, his and Lysecky’s most important work is educating future engineers who will solve the world’s problems—in this case, the environmental and climatic effects of growing energy consumption.