A multidisciplinary team of researchers at the University of Virginia has been awarded a four-year, $2 million grant from the National Science Foundation to develop “smart building” energy systems for residential and commercial buildings.
The researchers will focus on reducing energy used by buildings’ heating, ventilation and air conditioning (HVAC) systems. These systems are estimated to account for about 43 percent of all energy used by U.S. homes, and more than 60 percent used by homes in colder climates. Annually, HVAC use accounts for about 28 percent of the nation’s electricity use, according to the United States Energy Information Administration.
The plan is to develop sensors and user interfaces that will allow building occupants to better control the building temperature and enable the building to better sense and automatically respond to occupants. The team will also be designing new HVAC equipment and building exteriors, or envelopes, to improve the speed and efficiency with which buildings could respond to occupants.
“Right now, the prevailing wisdom is that buildings should be efficient in their steady state of operation; if you’re going to constantly heat the building, you should be efficient at doing that,” said Kamin Whitehouse, assistant professor in the Department of Computer Science and principal investigator for the grant. “We are going to dynamically control buildings, and so we need to revisit that whole philosophy and ask the question, ‘How can we design equipment and buildings to more quickly respond to occupant behavior?’”
Researchers will address this question by drawing on the expertise of faculty and students from the Engineering School’s Departments of Computer Science, Mechanical and Aerospace Engineering, and Systems Engineering, as well as those from the School of Architecture and Darden School of Business. The University researchers also will work with Staengl Engineering, a local energy-efficient HVAC and mechanical systems design firm, and with architect Carrie M. Burke.
An important goal for the project will be to develop systems that are more affordable than other popular energy-saving methods, such as installation of improved insulation, new windows or solar panels. Preliminary data from research conducted on eight houses in Charlottesville showed a 28 percent reduction in HVAC energy use with a $25 investment in hardware. Ultimately, the researchers hope to reduce HVAC energy use by 30 to 50 percent with a startup cost of less than $500 per home and a return on investment for homeowners within two years.
To meet the energy-reduction target, the researchers are developing a wide range of technologies, including next-generation wireless sensors, HVAC equipment, building envelope designs and human-computer interfaces. They will use sensors to monitor electric and water loads, occupant motion in buildings, door and window positions, light, temperature and humidity.
The project also will employ biometric height sensors to identify different residents in the home. Ultrasonic height sensors hidden above a house’s doorways are perceived to be less invasive than other identification technologies such as cameras or microphones.
On the most basic level, the sensor and instrumentation would allow a building to automatically detect when certain rooms are occupied and then automatically activate the heating or cooling system. The research becomes more complex when considering issues such as predicting when people would return to a building so that the system can preheat or precool spaces, the cost of sensors and the return on investment from energy savings.
Andrea Larson, a professor at the Darden School of Business, is helping the team of technology experts turn the energy systems into an economically viable product for consumers. One aspect of her work will be to determine the proper price point for these technologies to gain widespread consumer adoption.
“Technology can be ahead of the market, be hard to sell to its ultimate users and be priced inappropriately,” Larson said. “Early adoption, to be followed by widespread adoption, requires careful selection of first customers and your early supplier partnerships. It also requires a good understanding of the marketplace, including your strategy within the existing competitive context, how you are differentiated, the competition’s likely response, pricing and regulatory issues.”
Because adoption of an innovative system, such as smart building energy systems, requires that people change their existing patterns of behavior, an advanced analysis of market conditions will be essential. Larson’s work in this area will address economic and behavioral incentives for prospective users and buyers.
Larson notes that the project has to demonstrate that it can save money for people who purchase and use it. The financial returns and ancillary benefits, including improved air quality, greater comfort and therefore higher satisfaction and/or productivity, must be significant enough to attract investors as well as system purchasers. The systems would need to be attractive to a range of buyers encompassing homeowners, commercial building developers and owners, government agencies and schools.
In addition to dealing with financial considerations, the project calls for the technologies to be tested in a variety of commercial and residential sites: Charlottesville-area homes, a disaster recovery home built through the School of Architecture’s Initiative reCOVER, and the Engineering School’s upcoming Rice Hall Information Technology Engineering Building.
One of the dominant features of Rice Hall will be its ability to function as a “living laboratory” on energy use. Trane will be donating advanced HVAC systems for the building, and the NSF grant will allow researchers to develop, test and optimize sensors and instrumentation in the building.
Faculty and students from Initiative reCOVER, led by Anselmo Canfora, assistant professor in the School of Architecture, design prefabricated panelized housing for people displaced by natural and human-made disasters. The group’s current prototype house, which is now under construction at the decommissioned Milton, Va., airplane hangar fabrication facility, will allow researchers to see how best to integrate sensors and instrumentation into prefabricated wall panel systems.
reCOVER houses do not have mechanical HVAC systems, so they instead rely heavily on a passive building envelope design to control temperature by taking advantage of natural conditions such as sunlight and airflow. Data collected from the sensors will inform future building envelope designs for these houses.
Once their current prototype is complete, the reCOVER team hopes to deploy it in Haiti as part of an ongoing effort to address the dire need for housing earthquake survivors. Additional prototypes of the disaster recovery house will also be placed on other sites, researchers will simulate weather conditions to collect data from the sensors for their future designs.
“This is a great opportunity for us to work together as a truly interdisciplinary team,” Canfora said. “I think NSF’s vision to bring together architects and engineers to address issues of sustainability — specifically in energy conservation and management in buildings — will lead to significant benefits for occupants and, ultimately, our planet.”