Energies2015,8,10996-11029:doi:10.3390/en81010996 OPEN ACCESS energies ISSN1996-1073 www.mdpi.com/journal/energies Review A Review of Approaches for Sensing,Understanding,and Improving Occupancy-Related Energy-Use Behaviors in Commercial Buildings Hamed Nabizadeh Rafsanjani,Changbum R.Ahn and Mahmoud Alahmad The Durham School of Architectural Engineering and Construction,University of Nebraska-Lincoln, 113 NH,Lincoln,NE 68588-0500,USA;E-Mails:hnabizadehrafsanj2@unl.edu(H.N.R.); malahmad2@unl.edu (M.A.) Author to whom correspondence should be addressed;E-Mail:cahn2@unl.edu; Tel.:+1-402-472-7431;Fax:+1-402-472-3742. Academic Editor:Hossam A.Gabbar Received:2 June 2015/Accepted:24 September 2015/Published:1 October 2015 Abstract:Buildings currently account for 30-40 percent of total global energy consumption In particular,commercial buildings are responsible for about 12 percent of global energy use and 21 percent of the United States'energy use,and the energy demand of this sector continues to grow faster than other sectors.This increasing rate therefore raises a critical concern about improving the energy performance of commercial buildings.Recently, researchers have investigated ways in which understanding and improving occupants' energy-consuming behaviors could function as a cost-effective approach to decreasing commercial buildings'energy demands.The objective of this paper is to present a detailed, up-to-date review of various algorithms,models,and techniques employed in the pursuit of understanding and improving occupants'energy-use behaviors in commercial buildings. Previous related studies are introduced and three main approaches are identified:(1)monitoring occupant-specific energy consumption;(2)Simulating occupant energy consumption behavior; and (3)improving occupant energy consumption behavior.The first approach employs intrusive and non-intrusive load-monitoring techniques to estimate the energy use of individual occupants.The second approach models diverse characteristics related to occupants' energy-consuming behaviors in order to assess and predict such characteristics'impacts on the energy performance of commercial buildings;this approach mostly utilizes agent-based modeling techniques to simulate actions and interactions between occupants and their built environment.The third approach employs occupancy-focused interventions to changeEnergies 2015, 8, 10996-11029; doi:10.3390/en81010996 energies ISSN 1996-1073 www.mdpi.com/journal/energies Review A Review of Approaches for Sensing, Understanding, and Improving Occupancy-Related Energy-Use Behaviors in Commercial Buildings Hamed Nabizadeh Rafsanjani, Changbum R. Ahn * and Mahmoud Alahmad The Durham School of Architectural Engineering and Construction, University of Nebraska-Lincoln, 113 NH, Lincoln, NE 68588-0500, USA; E-Mails: hnabizadehrafsanj2@unl.edu (H.N.R.); malahmad2@unl.edu (M.A.) * Author to whom correspondence should be addressed; E-Mail: cahn2@unl.edu; Tel.: +1-402-472-7431; Fax: +1-402-472-3742. Academic Editor: Hossam A. Gabbar Received: 2 June 2015 / Accepted: 24 September 2015 / Published: 1 October 2015 Abstract: Buildings currently account for 30–40 percent of total global energy consumption. In particular, commercial buildings are responsible for about 12 percent of global energy use and 21 percent of the United States’ energy use, and the energy demand of this sector continues to grow faster than other sectors. This increasing rate therefore raises a critical concern about improving the energy performance of commercial buildings. Recently, researchers have investigated ways in which understanding and improving occupants’ energy-consuming behaviors could function as a cost-effective approach to decreasing commercial buildings’ energy demands. The objective of this paper is to present a detailed, up-to-date review of various algorithms, models, and techniques employed in the pursuit of understanding and improving occupants’ energy-use behaviors in commercial buildings. Previous related studies are introduced and three main approaches are identified: (1) monitoring occupant-specific energy consumption; (2) Simulating occupant energy consumption behavior; and (3) improving occupant energy consumption behavior. The first approach employs intrusive and non-intrusive load-monitoring techniques to estimate the energy use of individual occupants. The second approach models diverse characteristics related to occupants’ energy-consuming behaviors in order to assess and predict such characteristics’ impacts on the energy performance of commercial buildings; this approach mostly utilizes agent-based modeling techniques to simulate actions and interactions between occupants and their built environment. The third approach employs occupancy-focused interventions to change OPEN ACCESS