ASHRAE Journal - May 2013 - 94

EMERGING TECHNOLOGIES

Market Potential
The building energy monitoring and controls market is
expanding from conventional stand-alone systems to include
integrated and networked systems, both wired and wireless,
that enable more effective building energy management. A
broad-based survey of facility managers and IT directors
conducted by ON World revealed that a majority either already
used wireless sensors to support “smart building” initiatives
or expected to use WSN solutions near-term.10
An important part of the growth in adoption of WSNs for
building energy management systems is expected to be in
smaller commercial buildings, those less than 50,000 ft2 (4645
m2).11 The commercial availability of low-cost sensor and
control technologies should help reduce project payback time
in this building segment, now estimated to be about four years.
The added beneﬁt of easy-to-install WSNs will help maintain
a strong retroﬁt demand. Additional technology advances such
as low power Wi-Fi and energy harvesting to enable batteryless
sensors are also expected to help WSNs reach a worldwide
market value of $4 billion this year, with the U.S. accounting
for about half that value.11,12

References
1. IBM Final Technical Report, DE-EE0002897. 2012. “Recovery
Act: A Measurement—Management Technology for Improving Energy
Efﬁciency in Data Centers and Telecommunications Facilities,” http://
tinyurl.com/cogaqc3.
94

ASHRAE Journal

500
450

48% Cooling Load Reduction
17% Overall Data Center
Energy Reduction

400
350
300
kW

collected in a demonstration data center facility at the U.S.
Department of Agriculture’s National Information Technology
Center in St. Louis.
In this study, a total of 588 temperature and humidity sensors
were installed in the computer room air-conditioner (CRAC)
units as well as at the top, middle, and bottom of computer racks
measuring air intake and exhaust conditions at the IT equipment.
Additional subﬂoor reference temperatures were monitored
at selected racks. Sixty humidity/temperature sensors were at
the top of selected racks, and 18 pressure sensors were located
throughout the server room. In addition, power meters were
installed strategically on main power distribution panels.
The data helped identify contributors to suboptimal efficiency. Implementation of actions to improve efficiency
resulted in a 48% reduction in the data center’s cooling load,
compared to a baseline period in which the building’s WSN was
not deployed. Total data center power use was reduced by 17%.
Simple payback was calculated to be 3.4 years.9
Figure 1 shows the power use distribution by load, before and
after implementation of a WSN.8 The center was being overcooled
prior to the deployment of the WSN, and an appreciable amount
of energy was saved when this overcooling was addressed.
The GSA estimated that deploying similarly effective WSNs
throughout the 1,400 data centers it leases would result in a
total annual energy savings of more than 550 million kWh, for
an annual utility cost savings of $61 billion, based on a utility
cost of $0.11/kWh.8

250
200
150
100
50
0

Before

Refrigeration/Humidity
Fans
Lighting Load

After
Building & IT Load Loss
Generator Block/Radiator Heater
Computing Load

Figure 1: GSA wireless sensor network study results.8
2. Grindvoll, H., et al. 2012. “A wireless sensor network for intelligent building energy management based on multi communication
standards—A case study.” Journal of Information Technology in
Construction http://tinyurl.com/d8okz8c.
3. VanOort, A. 2013. “Wired, wireless sensors offer options.” ACHR
News http://tinyurl.com/cq2qb8z.
4. Huang, Q., et al.2011. “Environmental thermal energy scavenging
powered wireless sensors network for building monitoring.” Proceedings of the 28th ISARC. http://tinyurl.com/bo9k6o9.
5. Brambley, M.R., M. Kintner-Meyer, S. Katipamula, and P.
O’Neill. 2005. “Wireless Sensor Applications for Building Operation
and Management.” http://tinyurl.com/bkqpf6w.
6. U.S. Department of Energy, Oak Ridge National Laboratory.
2012. “Retro-Commissioning in Buildings: Using Wireless Sensors
for Improved Energy Efﬁciency.” http://tinyurl.com/d3g7z95.
7. PharmaManufacturing.com. 2009. “Genentech Gets More Wireless, Less Worry.” http://tinyurl.com/bpsgc74.
8. General Services Administration. 2012. “Wireless Sensor Networks, Findings.” http://tinyurl.com/cv826a2.
9. Lawrence Berkeley National Laboratory, report prepared for the
General Services Administration. 2012. “Wireless Sensor Network
for Improving the Energy Efﬁciency of Data Centers.” http://tinyurl.
com/9wjowjx.
10. ON World. 2009. “Wireless Sensor Networks for Smart Buildings—A Market Dynamics Report.” http://tinyurl.com/apc5uab.
11. GreenManufacturer.net. 2012. “Controls, Sensors Use in Building Energy Management Systems Forecast to Grow.” http://tinyurl.
com/b3wq4n4.
12. ON World. 2009. “Green Buildings are Gaining Momentum with
Wireless Sensor Networking” http://tinyurl.com/c5d8cps.

Mildred Hastbacka is a director and emerging technologies
scout for TIAX LLC and Ratcharit Ponoum is a senior technologist in the Electronic Systems Group of TIAX LLC, Lexington,
Mass. Antonio Bouza is a technical manager with the U.S.
Department of Energy, Washington, D.C.
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