A University of British Columbia (UBC) engineer has come up with a way to use Wi-Fi to determine the number of people in a building and adjust its ventilation accordingly, allowing for energy savings without sacrificing air quality.
“Every day, thousands of smartphones, laptops and tablets connect to the Wi-Fi network at UBC,” said Stefan Storey, the engineer, who holds a master’s in mechanical engineering and a PhD in resource management and environmental studies from UBC. “Our Bridge software anonymously counts the number of wireless devices in each room and passes the counts on to UBC’s building control system, which then adjusts airflow through the relevant building, practically in real time.”
Based on the number of occupants in the building, the control system can vary the airflow to a room, increasing it during a busy lecture or turning it down during the times in between.
UBC and Storey tested the technology at the Irving K. Barber Learning Centre library, which serves thousands of students and staff. The test found that this technology reduced energy consumption by five per cent over a period of 12 months, while maintaining air quality and occupant comfort.
According to David Woodson, UBC’s managing director of energy and water services, the new system could help the university cut greenhouse gas emissions by hundreds of tonnes and save up to $100,000 in energy costs per year for core campus buildings. UBC plans to install the technology in 10 more buildings over the next several months.
“This software uses the existing Wi-Fi network to provide good air quality and thermal comfort, so costs are lower and disruption is less compared to other occupancy detection technologies,” said Woodson. He went on to say that UBC’s Wi-Fi users are completely protected as all private information is removed in strict compliance with Canadian privacy legislation.
According to Storey, this project highlights the potential benefits of using Wi-Fi systems to create “smart buildings.” Storey co-founded the company Sensible Building Science around this discovery, with support from entrepreneurship@UBC, which provides help to UBC students, alumni, faculty and staff entrepreneurs as they develop and market their ideas. His patent-pending innovation is now being installed at campuses across B.C.
“As far as I know, this is the first technology in North America to use Wi-Fi access points as a sensor network and as a way to communicate with building control systems,” said Storey. “As we continue to develop it, we can help many more buildings become much more responsive to occupant needs.”
