Buildings use a lot of electricity. According to the U.S. Energy Information Administration, residential and commercial buildings consume about 40% of the total U.S. energy production. Generally, the majority of a building’s use of electricity goes towards powering lighting, plug load, as well as heating, ventilation and air conditioning (HVAC).
There are many options for controlling costs associated with a building’s use of electricity, such as occupancy sensors. Through building automation systems, occupancy sensors are devices that give their user the ability to turn on and off any appliance that plugs into a standard wall socket, as well as lights. “When connected to a smart computerized system, occupancy sensors not only have the ability to greatly reduce the electricity loads from lighting and controllable plug loads, but also can significantly lessen the heating and cooling energy consumption from HVAC systems,” explains Gang Wang, assistant professor in the University of Miami College of Engineering’s (UMCoE) Department of Civil, Architectural and Environmental Engineering. “The system can detect when the user is not in a room or building and send an ‘occupancy signal’ to automatically turn off appliances – such as computer monitors – and lights that consume energy in standby mode, as well as reduce the airflow rate and outdoor air intake of HVAC systems.”
However, occupancy signals greatly increase the dynamics of HVAC systems and introduce inconsistent behaviors, which reduce the efficiency of the HVAC operating units and can be damaging to the HVAC systems in the long run. “The elevated dynamics generate challenges for reliable HVAC operations and therefore prevent the implementation of integrated operations for maximum efficiency,” says Wang.
Wang recently received funding from the U.S. Department of Energy (DOE) to remedy the HVAC efficiency problems related to occupancy signals in commercial buildings. His proposed project, titled, “Performance Demonstration of an Occupancy Sensor-Enabled Integrated Solution for Commercial Buildings,” will attempt to validate a lab-tested algorithm package that theoretically can reduce a typical commercial building’s energy consumption by about 19%.
Wang’s research proposal is one of 19 projects that were selected by the DOE’s Building Technology Office to drive innovation in early-stage research and development for advanced building technologies and systems that will serve as a foundation for future technological developments and reductions in building energy consumption. The award, officially known as the Building Energy Efficiency Frontiers and Innovation Technologies (BENEFIT) Award, is part of the DOE’s $42 million investment in project selections to support early-stage research and development (R&D) of innovative residential and commercial building technologies for energy efficiency.
The multidisciplinary project – led by Wang – consists of team members from both academia and industry. Wang will be collaborating with Li Song, associate professor of the school of aerospace and mechanical engineering at the University of Oklahoma, Hunter Miles, automation and energy account executive with Siemens Industry, Inc., Joey Hunter, base energy manager with Tinker Air Force Base, and Pat Saxton, federal energy solutions manager at Oklahoma Gas and Electric (OG&E).
The project will focus on testing the previously developed algorithm by building demonstrations that introduce dynamic, real world conditions. Specifically, Wang plans to show the effectiveness of the proposed algorithm package in two buildings: one small building with remote terminal units, a multipurpose device used for remote monitoring and control of various devices and systems for automation, and one medium/large building with built-up air handling units, a device used to regulate and circulate air as part of the HVAC system.
“The importance of the project lies in ensuring that occupancy sensors improve the efficiency of lighting and plug-load without disrupting the operations of HVAC systems,” explains Wang. “If the demonstrations prove the algorithm successful, we can use the results to promote the technology and encourage its adoption. This will lead to game-changing opportunities in the development of HVAC control technology and contribute to the new age of smart buildings and cities.”
To learn more about the other 18 BENEFIT projects selected by the DOE Building Technology Office, please click here.
