Abstract

The presentation will discuss about the possibilities of enhancing building energy efficiency and Indoor Environment Quality (IEQ) using occupancy information through an in-depth case study of an existing floor of an institutional building. In this study, Zone-level time series operational data of plug, lighting, and HVAC energy use has been analysed to identify the implications of occupancy-based control of energy systems on the energy efficiency and IEQ.

In the process of analysing plug and lighting energy use, a new parameter, ‘Energy-use per person (Epp)’ is introduced to explain the variability in energy use at similar occupancy levels. The Epp model developed is used to estimate possible energy savings during occupied hours with a rule-based energy-use behaviour. The estimated plug load savings from this model are 8.9%, 3.1% and 1.3% for the classroom, open office, and computer room respectively. Concurrently, possible lighting energy savings are 65.1%, 43.6% and 38.4% for the classroom, open office, and computer room respectively. In the process of analysing HVAC energy use, the zonal supply air rate has been optimized keeping the ventilation inside a zone to the minimum requirement based on occupancy information and zone temperature constraints. The result of the analysis shows possible HVAC energy savings of up to 23%, 19%, 21% and 34% for the classroom, computer room, open office and closed offices respectively when supply air rate is adjusted to maintain zone temperature up to 24°C based on occupancy information. The HVAC energy savings can reach as high as 34%, 38%, 31% and 34% for the classroom, computer room, open office, and closed offices respectively, if the temperature of the unoccupied zone is increased up to 28°C or ventilation of unoccupied zones are discontinued. Finally, the outcomes of plug, lighting, and HVAC energy analysis are integrated to propose a methodology which uses this study for both analysis and real-time control of plug, lighting, and HVAC energy use for the individual zones of any building based on their occupancy information.

Dr. Prashant Anand is currently a Research Fellow at the Centre for Integrated Building Energy and Sustainability at the Tropics (CiBEST) of the National University of Singapore. His research area is mainly building science with a focus on occupancy-based building system control. Prashanth holds an undergraduate degree in Architecture from NIT Patna followed by a Master's degree in Building Technology and Construction Management from IIT Madras. He later received his Ph.D. From the Building Department of the National University of Singapore with a NUS Research Scholarship. Before his research career, he had both teaching and industry experience. Prashant is currently an Associate Member of the ASHRAE Singapore chapter, executive committee member of the IBPSA Singapore chapter, and member of ISIAQ Europe.