This pledge closed almost 3 years ago
General contractor: Johnson
Controls Energy Solutions Group
Engineer: Air Systems Engineering
Owner: Metro Parks Tacoma
ABC member: Merit Mechanical
The Centre at Norpoint in Tacoma is
a 45,000-square-foot community center housing a large swimming pool,
gymnasiums, racquetball courts, day-care facilities, fitness centers, locker
rooms, offices and meeting rooms.
For some time, Metro Parks Tacoma
had been calling in Air Systems Engineering
regularly to care for the center's aging mechanical systems. But in July 2011,
Air Systems was invited to partner with Johnson Controls Energy Solutions Group
to build a new and upgraded energy-efficient mechanical plant — essentially the
equivalent of a heart transplant — for the center.
The design called for installation
of two highly
energy-efficient boilers, 15 air-handler coils, and five pumps and heat
exchangers for the pools, domestic hot water and space heating.
The three-week shutdown to upgrade
the mechanical plant was a coordination challenge. There was a lot of work to
do and much of it needed to be done in a small boiler room in the extreme heat
of the summer.
Air Systems realized early on that
the pool's existing air-to-air dehumidification unit could be modified by
adding a new air-to-water heat pump that could preheat make-up water for the
pool. This constant energy source would be much more valuable as a heat source
for the main system water loop, creating a more favorable operating
cost-benefit ratio, so it was added at no additional cost to the client.
One of the challenges in this
project was the diligent coordination of people and time, as there would need
to be scheduled interruptions for no-heat shutdowns and safe work practices
around the public, including the need for warm pools and hot showers when local
schools used them in early September. To accommodate these needs, Air Systems
performed the demolition, poured the concrete pads and set the major equipment,
then concurrently performed the change-out of 17 air-handler coils, plus all of
the electrical wiring and motors.
The boilers were designed with a
dual-fuel feature, able to operate on either propane or natural gas. Two
1,000-gallon propane and natural gas tanks were originally supposed to be
installed in a fenced area behind the facility, but Metro Parks was wary that
such an enclosure might be an eyesore as well as a liability to the adjacent outdoor
water park. So the decision was made to bury the tanks.
Once the old boilers were gone, the
team realized that if it expedited the permitting and installation of the new
tanks, it would be able to stay on schedule. Once installed, the boilers were fired
up on a Friday afternoon and the 60,000-gallon pool was 85 degrees by Sunday.
The design-build process for this
project allowed Air Systems to adapt and consult quickly with the engineers
during job site challenges.
With all of the safety measures in place
and executed, plus additional oversight by the job superintendent, there were
no incidents or injuries during the 1,355 hours worked on the project.