Non-Intrusive Occupancy Monitoring for Energy Conservation in Commercial Buildings

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In 2018, a study was conducted regarding monitoring building occupancy in commercial sectors using non-intrusive methods to conserve energy. The research article, aptly titled “Non-Intrusive Occupancy Monitoring for Energy Conservation in Commercial Buildings,” was published in the journal Energy & Buildings, a peer-reviewed international journal that publishes scientific research.
This paper explores the use of non-intrusive techniques to estimate occupancy in commercial buildings based on existing HVAC sensors. Traditional fixed schedules for HVAC systems do not take occupancy into account, resulting in wasteful energy consumption. By using non-intrusive techniques to estimate occupancy and developing adaptive energy-efficient schedules, the authors were able to reduce reheat energy consumption by over 38% while maintaining indoor thermal comfort. The proposed techniques can uncover recurring occupancy patterns in individual zones, leading to significant energy savings.
The paper’s methodology involves assessing the potential of scalable time series analytics to estimate occupancy at the individual zone level. The study uses a testbed comprising three large campus buildings with Building Management Systems installed by different vendors. The buildings contain a total of 496 zones, with data collected over three months.
The paper evaluates the effectiveness of existing energy-saving strategies and collects ground truth data on occupancy hours manually and via a security camera installed in a lab with heat-generating equipment. Stratified sampling of occupancy is used to develop the solution, as collecting ground truth occupancy data from every zone in a large building is not feasible.
The article discusses the use of an HVAC schedule to control the operation of a VAV in a building’s management system. Most commercial buildings operate on a fixed schedule set by the facilities manager, which is conservative to maintain occupants’ comfort. The article proposes using the apparent occupancy profile for each thermal zone to develop VAV operation schedules, which can result in energy savings and quantifies the energy savings and occupant comfort violations of the proposed schedules.
The percentage of energy saved on reheat is calculated as the ratio of reheat energy saved during the operation of a VAV under a schedule to a baseline obtained from the building’s current operation, while the percentage of occupant comfort violations quantifies the mismatch between a schedule and actual occupancy. This is an incredible way to cut down on energy consumption and electricity costs, and solutions like these set MMG engineers apart from everyone else.
Our team of experts at MMG Engineering Pvt. Ltd. is trained in vastly different solutions which cater specifically to our clients, helping them in a way that is suited best to their needs.