januaryfebruary2021 - 15

AIRSIDE
throughout the day. It could range
from freezing overnight to a more
moderate temperature by midday; and
for this reason, the airport wanted a
fast-reacting PCA plant design, " said
Landrum. " This ability to transition
quickly between heating and cooling
was a top design priority and that's
where this PCA plant excels. "
Another key design feature of the
SLC PCA central plant is the system's
built-in redundancy. An issue that affects
many central PCA systems is if a pump
fails, it takes the entire PCA plant with it.
SLC's plant was built with dual pumps
at each pump location to eliminate this
risk. " Every pump we have here has a
redundant spare, so to speak. So that if
there is a pump failure it automatically
swaps over from the faulty pump to the
spare, to allow repair without shutting
down the PCA plant. We also have
controls in place that balance run hours
on all equipment. We have endeavored
to design this system to be as bulletproof
as possible, " Landrum said.
Building in this redundancy was
one of the requests SLC had for ASE
when the company first began designing
the project in 2014. Construction for
the project began in 2017, and currently
two PCA plants are online at the airport
- the South Concourse West plant and
the North Concourse plant. The third
is the South Concourse East plant which
is currently under construction. Once
online, all three PCA plants will work
in tandem, serving a combined 78 gates.
" It was clear during design that SLC
wanted to incorporate innovation by
implementing the latest and greatest
sustainable technologies. " Landrum said.
" The building air conditioning
system uses a free cooling scenario with
Indirect/Direct Evaporative Cooling
(IDEC) units. Since SLC has relatively
low humidity, they are able to use
cooling tower water for comfort cooling
of the airport concourses. After the
tower water goes through the comfort
cooling IDEC units, it comes our way, "
Landrum described. " ... at which point
that water cools our PCA chillers and
returns to the cooling tower. "
" We worked in combination with
Colvin Engineering on this effort to
essentially synchronize our PCA plant
with their IDEC system, and make sure

Every pump has a spare
redundant pump to
improve availability. Color
coded piping helps to quickly
identify system components.
that everything was sized effectively, to
handle both the free cooling for comfort
cooling in the concourse, as well as the
heat rejection for PCA plant chillers. "
he continued.
" By using a 30 percent propylene
glycol mixture with water, the PCA
system is more environmentally friendly
than the typical ethylene glycol solution.
There are 2,500 ton-hours of thermal
storage per plant that is used to shift
power usage from high peak rate hours
during the day to the lower cost off-peak
rates at night. " Additionally, the thermal
storage allows for some redundant
cooling capacity in the event of a chiller
outage.

" Because we have a signif icant
efficiency advantage over the DX point
of use style units, we were able to earn
multiple LEED Energy and Atmosphere
credits. Using the central plant over the
DX units helped this project advance
from a Silver to a Gold LEED rating, "
Landrum added.
As this was a LEED project, it
required a lot more monitoring
functionality to track energy usage
on top of the built-in monitoring that
comes from tying the three PCA plants
together.
" You can look at any gate on the
three concourses from any of the
monitoring stations. That gives the end

KEY MEMBERS OF THE SLC
AIRSIDE PROJECT TEAM:
f SLC Airport Redevelopment Program
Management Team (PMT) - Program
Management

f RK - South Concourse Mechanical
Contractor

f HOK - Lead Architect

f Austin-Okland - North Concourse
General Contractor

f Colvin Engineering Associates -
Building Mechanical Design Engineer

f J&S Mechanical - North Concourse
Mechanical Contractor

f AERO Systems Engineering -
Preconditioned Air and Airside Designer

f Siemens - Controls Contractor

f Holder Big-D - South Concourse
General Contractor

f JBT - Airside Systems Manufacturer
f AERO BridgeWorks - Airside
Equipment Installation

JANUARY/FEBRUARY 2021 \ AVIATIONPROS.COM / 15
http://www.AVIATIONPROS.COM
januaryfebruary2021

Table of Contents for the Digital Edition of januaryfebruary2021
