By: Robert Thompson, PE, Chief Mechanical
Engineer, SmithGroupJJR and Otto Van Geet, PE,
Principal Engineer, National Renewable Energy
Nearly 40% of the total U.S. energy con- sumption in 2012 was consumed by residential and commercial buildings,
according to the U.S. Energy Information
Administration. While each building is a
consumer of energy, they also contain energy
resources that are under-utilized or not even
considered as energy resources. Most energy-reduction efforts focus on the optimization of
individual systems in isolation, but rarely step
back to consider the building as a whole. Even
less frequently does a corporation consider the
potential consolidation of programs for a long-term energy benefit.
A common scenario involves the consoli-
dation of an office and a lab in a single facility.
ASHRAE Standard 90.1 requires energy recov-
ery above a minimum design outside airflow
percentage and based on the climate zone. An
office and an adjacent lab served by independent
systems are subject to this requirement, with the
lab likely requiring a minimum 50% effective
exhaust energy-recovery system to be in compli-
ance. While the result of ASHRAE 90.1 compli-
ance is increased system efficiency, the overall
building performance can be further improved
by serving both areas with a common system.
This systems integration approach provides
a reduction in first cost, as well as an ongoing
energy-use reduction. The first-cost reduction
comes from the elimination of the office energy-recovery system. The ongoing energy-use
reduction comes from lower volumes of outside
air to be conditioned (outside air for the office
is reused as a portion of single-pass ventilation
of labs). This same systems integration concept
can also be applied to other building programs
for a significant energy improvement.
Labs and data centers are some of the largest
energy consumers for buildings. Labs operate
continuously and must condition large quantities of outside air. Data centers also operate
continuously and require on-going cooling for
computer equipment. While these programs
seem quite different on the surface, they can
be integrated in a way that complements the
energy needs of both.
Data centers reject “waste” heat to their
surrounding environment. A lab located in a
cooler climate will require a large amount of
heating in winter. If the “waste” heat from the
LaboratoryDesign|NOV|DEC 2014 27
continued on page 28
Energy optimization and reuse through systems integration
Environmentally friendly solutions for
the laboratory market…worldwide
Tuttnauer USA Co. Ltd., 25 Power Drive, Hauppauge, NY 11788
Tel: 800 624 5836 x112, (631) 737 4850, Fax: 631 737 1034
Email: info@tuttnauerUSA.com, www.tuttnauerUSA.com
NREL’s ESIF data center energy-recovery system.
Image: Dennis Schroeder.