  The vast number of facility management systems, home automation systems, and
the ever-increasing number of Internet of Things (IoT) devices are in constant
need of environmental monitoring. Indoor environment data can be utilized to
improve indoor facilities and better occupants' working and living experience,
however, such data are scarce because many existing facility monitoring
technologies are expensive and proprietary for certain building systems, such
as building automation systems, energy management systems, and maintenance
systems. In this work, the authors designed and prototyped a cost-effective,
distributed, scalable, and portable indoor environmental data collection
system, Building Data Lite (BDL). BDL is based on Raspberry Pi computers and
multiple changeable arrays of sensors, such as sensors of temperature,
humidity, light, motion, sound, vibration, and multiple types of gases. The
system includes a distributed sensing network and a centralized server. The
server provides a web-based graphical user interface that enables users to
access the collected data over the Internet. To evaluate the BDL system's
functionality, cost-effectiveness, scalability, and portability, the research
team conducted a case study in an affordable housing community where the system
prototype is deployed to 12 households. The case study results indicate that
the system is functioning as designed, costs about \$3500 to sense 48 building
zones (about \$73 per zone) and provides 12 types of indoor environment data,
is easy to scale up, and is fully portable.
