Central Blood Bank
Problem
Sometimes cooling needs go beyond comfort. Central Blood Bank, the fourth
largest blood collection agency in the nation, requires critical cooling to save
lives. Built in redundancy is not an option, it’s a requirement. So when the Pittsburgh
Central Blood Bank facility decided to move to an existing building to accommodate
its growth, the nonprofit faced several challenges. First and foremost, the facility
needed 100 percent chiller uptime because its freezers and refrigerators need to
maintain constant temperatures for the blood products and to provide constant data
infrastructure to track the processing, history and distribution of blood. If the
IT equipment room deviates from a range of 68 to 72 degrees, critical data could
be lost and blood product rendered useless, directly jeopardizing thousands of lives
at five major medical complexes in the region. In addition, Central Blood Bank was
relocating to a building adjacent to a residential neighborhood, so evening noise
was a concern since blood collection and storage is a 24/7 operation. Finally, the
Central Blood Bank’s “new” four-story facility offered logistical and maintenance
challenges for the engineering team designing the cooling system; the existing roofmounted
split-system chiller’s removal required the new design to incorporate a base rail
system that would match the existing structural supports.
Solution
Loftus Engineers, in Pittsburgh, PA, designed an elegant solution to meet
Central Blood Bank’s challenges. Four Airstack chiller banks providing 330 tons
of cooling were designed to be mounted on the roof of the 185,000 square-foot facility,
ensuring the blood products are kept at constant temperatures. With redundancy a
priority, Loftus selected Multistack chillers due to their modular multiple compressor design.
Only one compressor at a time stages on automatically to meet the cooling load.
If a compressor were to fail additional compressors sequentially start due to the
inherent built-in redundancy. In the event of a power failure, the emergency backups
run sequentially so Central Blood Bank doesn’t need to start a large compressor,
saving the nonprofit 30-50 percent generator size and capacity. In addition to reliability,
efficiency was another critical issue factored in the decision to go with Multistack
chillers. Central Blood Bank wanted a system that only operated compressors when
required. And, with Pittsburgh temperatures frequently dropping into the midteens
in the winter months, Loftus Engineers incorporated the use of free-cooling modules
to provide 60- tons of compressor-less wintertime cooling. Maintenance was also
a major concern, but a majority of Multistack’s parts are available off-the-shelf
from local suppliers, and the multiple compressor design eliminated the need for
cranes to lift large compressors to the roof, allowing installers to utilize the
buildings elevators and steps during service calls. The Multistack chillers also
offer an added benefit in noise reduction. Multistack’s “Airstack” chillers average
10-12 dB lower sound levels than the building’s previous cooling system.
Result
Since its building renovations were completed more than two years ago, Central
Blood Bank’s critical cooling needs have never been compromised. Multistack’s Airstack
chillers have never failed. The Airstack chillers, provided with environmentally
friendly 407C refrigerant, maintain constant temperatures at the facility that produces
five different end products, including blood platelets, red blood cells and cryoprecipitate,
for five major hospitals. The institution uses three 27 x 15 foot and one 30 x 13
foot freezers to store blood and blood products at -30 degrees C during the processing,
while refrigerators remain at a constant 4 degrees C. After processing, glycerin
is added to some products which require storage even colder at -125 degrees C. The
laboratory also is served by redundant air handlers with 100% back-up requiring
the same critical 24/7 back-up cooling to process blood during disaster emergencies.
Central Blood Bank’s data systems and IT infrastructure maintain constant temperatures
around the clock as the nonprofit continues to serve more than half a million patients
a year. “Multistack has a clear understanding of the keys to success,” said Central
Blood Bank’s facility manager, Jim Miller. “It’s about integrity, innovation, and
professionalism…they say what they are going to do and follow-through 100 percent
of the time. And in our business, there’s more than comfort at stake when we talk
about critical cooling and redundancy. After all, we’re in the business of saving
lives.
Case Study