Energy and Buildings 82 (2014) 341–355
Contents lists available at ScienceDirect
Energy and Buildings
j ourna l ho me page: www.elsevier.com/locate/enbuild
Occupant behavior and schedule modeling for building energy
simulation through office appliance power consumption data mining
Jie Zhao
*
, Bertrand Lasternas, Khee Poh Lam, Ray Yun, Vivian Loftness
Center for Building Performance and Diagnostics, School of Architecture, Carnegie Mellon University, 5000 Forbes Avenue, MMCH-410-IW, Pittsburgh, PA
15213, USA
a r t i c l e i n f o
Article history:
Received 28 April 2014
Received in revised form 3 July 2014
Accepted 15 July 2014
Available online 23 July 2014
Keywords:
Occupant behavior
Occupancy schedule
Data mining
Plug load
Office appliance
Energy simulation
EnergyPlus
Climate zone
Decision tree
Linear regression
a b s t r a c t
The occupants’ health, comfort, and productivity are important objectives for green building design and
operation. However, occupant behavior also has “passive” impact on the building indoor environment
by generating heat, CO
2
, and other “disturbances”. This study develops an “indirect” practical data min-
ing approach using office appliance power consumption data to learn the occupant “passive” behavior.
The method is tested in a medium office building. The average percentage of correctly classified indi-
vidual behavior instances is 90.29%. The average correlation coefficient between the predicted group
schedule and the ground truth is 0.94. The experimental result also shows a fairly consistent group
occupancy schedule, while capturing the diversified individual behavior in using office appliances. Com-
pared to the occupancy schedule used in the Department of Energy prototype medium office building
models, the learned schedule has a 36.67–50.53% lower occupancy rate for different weekdays. The
heating, ventilation, and air conditioning (HVAC) energy consumption impact of this discrepancy is inves-
tigated by simulating the prototype EnergyPlus models across 17 different climate zones. The simulation
result shows that the occupancy schedules’ impact on the building HVAC energy consumption has large
variations for the buildings under different climate conditions.
© 2014 Elsevier B.V. All rights reserved.
1. Introduction
1.1. “Active” role of occupants
The occupants’ health, comfort, and productivity are considered
as key objectives for green building design and operation. At the
same time, the occupants play a critical “active” role in the build-
ing operation. Occupant behavior and feedback are necessary to
achieve the desired total building performance [1].
Numerous studies have developed various control systems and
modeling methods to better assist occupants to play their “active”
roles in buildings. Table 1 shows a summary of reviewed litera-
tures of occupants’ “active” influence in buildings. 10 out of 15
studies demonstrate an energy impact of occupant behavior by
using various individualized control systems and dashboards for
building heating ventilation and air conditioning (HVAC), lighting
and plug load systems. Four studies about post occupancy eval-
uation and complain handling show the occupant feedback can
be useful for building diagnostics. Another four studies show that
*
Corresponding author. Tel.: +1 412 268 1492.
E-mail addresses: jayzhao@cmu.edu, jiezhao.cmu2010@gmail.com (J. Zhao).
providing occupants with individualized controls can influence
their thermal comfort. Three studies show that providing the
occupants with individual controls can improve their subjective
satisfaction towards their working environment.
1.2. “Passive” role of occupants
The studies above suggest that the occupant’s “active” feedback
and behavior has strong influence on the indoor environment and
building HVAC, lighting, and plug load system energy consump-
tions. Similarly, the occupant’s “passive” role also has impact on
the building performance. Particularly, for the building thermal and
indoor air quality performance, occupants are treated as “mobile
heat and CO
2
sources”, which can influence the HVAC energy con-
sumption to a great extent. Hence, the occupants are typically
treated as “disturbances” in the HVAC control system. It is criti-
cal to study the occupant individual behavior and group schedule
to uncover this “passive” impact.
The following studies show that the occupants “passive” behav-
ior have a significant impact on building energy consumptions.
The simulation study in Ref. [17] showed that “for a typical single-
occupancy office room, compared to the standard or reference work
style, the austerity work style consumes up to 50% less energy,
http://dx.doi.org/10.1016/j.enbuild.2014.07.033
0378-7788/© 2014 Elsevier B.V. All rights reserved.