Engineering Inc. - Winter 2020 - 21

equipment out right after they shut down
the chiller system for the winter," Hanegan
says. "Also, we designed the system in
collaboration with the contractor so that as
much as possible could be shop fabricated,
then bolted together in the field."
This approach reduced the amount of
field welding required, saving time and
ensuring top quality. And as Hanegan
and her team were working on the design,
they saw an additional opportunity for
improvement.
"We realized that to lay out all the equipment for optimum access, we wanted to
take out the hospital's domestic hot water
system," Hanegan says. "The hospital had
been wanting to get rid of some big storage
tanks for their hot water system because they
posed a risk for Legionella."
To maintain a supply of hot water during
the renovation, a new connection was made
to the emergency department's hot water
heater to back feed the main facility.
The project resulted in a large reduction in the risk of Legionella bacteria for the hospital and extra space to better accommodate the new chilled water system layout. Plus, leaving the
connection to the emergency department water heater in place
after the new system had been installed provides a backup for
future use that was not previously available.
This multiphase, integrated project has been successful in
both operational and financial terms. In addition to a smooth
startup, the new chilled water system saved $74,000 in utility
costs in its first year of operation. The hospital also received an
incentive check from the local utility company for $181,000.
According to Hanegan, projects for institutional facilities that
need to grow or upgrade for new technology and equipment are
among the most complex projects the company does.
"It is a bit like doing open heart surgery, trying to work on
something while keeping it going," Hanegan says. "When we do
that kind of renovation work, it makes us better on the projects
where we are designing a brand new facility. We think about
what needs to happen so the facility can be renovated in the
future." ■
COFFMAN ENGINEERS, INC.

The new 4,000-ton
capacity central chilled
water plant at Providence
Sacred Heart Medical
Center, Spokane,
Washington. The original
chilled water plant, built
in 1971, had undergone
several equipment
upgrades in the past few
decades.

can range from making relatively minor modifications to
accommodate a new piece of equipment to the complete
replacement of major mechanical systems. In the case of health
care, the engineering required can be particularly challenging
because facilities must remain functional.
A case in point: a recent chiller plant replacement at
Providence Sacred Heart Medical Center in Spokane,
Washington. The existing facility had begun to experience
failures and required costly maintenance to keep the current
equipment operational. Beyond that, the facility no longer
had the redundancy for its systems to meet current code
requirements.
To update the facility, Coffman Engineers, Inc., designed a
replacement system that uses a series counterflow approach and
new chillers with magnetic bearings, both of which are energy
efficient. In addition, the new chillers operate much more
quietly than the old ones. However, a big part of the chiller
plant replacement project was scheduling.
"There is a window of time each year where they do not need
the chiller plant, from about Halloween until April 1," says Traci
Hanegan, principal and lead mechanical engineer at Coffman
Engineers. As a result, the entire system could be removed and
replaced without disrupting operations.
"We coordinated with the contractor to take the old

Tom Klemens is a freelance writer based near Chicago and a
registered professional engineer in Illinois.

"There are a lot of doctors and research companies that are
looking for space to do their experiments."
JOHN BARANELLO
PRINCIPAL
SEVERUD ASSOCIATES

WINTER 2020

ENGINEERING INC.

Engineering Inc. - Winter 2020

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