| |
Commissioning Existing Hospitals: What are the Opportunities?
David E. Claridge, Ph.D.,
P.E., Texas A&M University
Hospitals are often viewed as buildings that offer little opportunity
for improving operational energy efficiency through commissioning.
They typically have requirements for large amounts of outside air
and must operate continuously. Some spaces have requirements for
very low humidity and/or temperatures.
During the last decade, Energy Systems Laboratory personnel have
conducted retro-commissioning assessments and/or implemented commissioning
measures in over two dozen existing hospital facilities. These facilities
run the gamut from a small 35-bed county hospital to some of the
largest hospitals in the country, and are located in all parts of
the United States. Some were less than two years old when commissioned
and others are approaching the century mark. As hospital facilities,
all have had higher energy use than the average U.S. building, but
some have had relatively low use for hospital facilities while others
have had exceptionally high energy use. The one common characteristic
shared by all has been the presence of opportunities for truly significant
energy (typically 10 to 20+ percent) and operating cost savings
that did not require any significant capital investment.
The opportunities identified and implemented cover a broad spectrum
of Labs21 measures within the HVAC (heating, cooling, fans, and
pumps), service hot water, and laboratory ventilation and exhaust
systems. These include minimizing or eliminating simultaneous heating
and cooling, reducing outside airflow during unoccupied periods,
minimizing maximum outside airflow to 1 cubic feet/minute/sq. ft.
or less when appropriate, and ensuring that energy recovery equipment
operates properly. Other opportunities often encountered include
optimizing terminal box set-up, resolving duct distribution problems,
improving air handler schedules and set-points, and opportunities
to improve the operating efficiency of chiller and boiler plants
and thermal storage systems. This presentation will summarize these
opportunities and the cost savings produced along with specific
examples of measures and their measured impact on operating cost.
Labs21 Connection:
The projects reported here do not represent laboratory design projects
or equipment upgrades, but they are very consistent with the Labs21
goal of optimizing the energy performance though they occasionally
include minor equipment changes. These projects almost exclusively
reflect the results of what can be called "practical"
optimization of energy performance of the existing systems. This
is achieved by applying fundamental engineering principles and experience
to achieve these improvements.
Biography:
David E. Claridge, Ph.D., P.E., is the Leland Jordan Professor
of Mechanical Engineering at Texas A&M University and Associate
Director of the Energy Systems Laboratory in charge of the commissioning
and analysis activities within the laboratory. Dr. Claridge has
over 30 years of experience in energy analysis and measurement in
buildings at Stanford University, the Office of Technology Assessment
of the U.S. Congress, the Solar Energy Research Institute, the University
of Colorado, and at Texas A&M University. He has been the Principal
Investigator on over $8 million in research projects. He has worked
extensively on building energy calculation methods, ground coupled
heat transfer, methods used to diagnose HVAC operating problems
and methods used to measure energy efficiency savings in buildings.
He has led out in development of the Continuous Commissioning®
process of system fine-tuning which has saved over $75 million in
over 300 buildings.
He has served as a member or officer of numerous ASHRAE and the
American Society of Mechanical Engineers (ASME) committees, and
currently serves as a U.S. delegate to the International Energy
Agency Annex 47 on Commissioning of Existing and Low Energy Buildings.
He is the author of over 300 publications and over 100 reports dealing
with analysis and measurement of energy use in both residential
and commercial buildings. He is a recipient of the E.K. Campbell
Award and the Distinguished Service Award from ASHRAE, a Faculty
Distinguished Achievement in Research Award from the Texas A&M
Association of Former Students and has received three Best Paper
Awards from ASME.
Back to the Agenda
|
