ASHRAE Journal - September 2022 - 50

ASHRAE TECHNOLOGY AWARD CASE STUDIES
thermal comfort in the atrium design with curtainwall.
Envelope commissioning was conducted to ensure the
envelope was constructed as designed.
The Exact Sciences' facility team reports that thermal
comfort design strategies have been successful as temperature
complaints are minimal.
Innovation
Innovative design elements support indoor environmental
quality, resiliency, water stewardship and fl exibility
for future manufacturing processes. Examples:
* Energy and water metering throughout the building
to capture major end uses and allow for monitoring and
improvement;
* Redundant chillers, boilers and refrigeration
systems, combined with dual-utility feeds and on-site
generators;
* Weather modeling shows that ice falling from a
neighboring broadcasting tower put the rooftop at risk.
The fi nal design involved moving key equipment away
from the hazard and protecting the roof membrane and
critical equipment with roof pavers and metal grating;
* Blower coil units manage the sensible load for
equipment-driven spaces, which achieves the intent and
energy performance of chilled beams while avoiding
water piping above critical equipment.
Operations & Maintenance and Cost Effectiveness
Ease of operation, maintainability and cost effectiveness
were major factors in choosing the fi nal systems.
Exact Sciences prefers air-cooled chillers from an operations
and maintenance standpoint. Summer operation
does not require water or chemicals, and warm winter
days allow for effi cient operation without water waste
from fi lling and draining the tower. On cold winter days,
waterside-economizing dry coolers are operated for free
cooling benefi ts.
The team worked with chiller manufacturers to understand
and model chiller curves for each consideration
to ensure an informed decision. With energy modeling
results, the design team conducted a cost benefi t analysis
of multiple air-cooled chillers; added cost studies were
also performed throughout the project to evaluate the
best choices for chilled beams, blower coils, alternatives
to glycol, alternative refrigerants and chilled water
storage. Annual operational costs, energy modeling and
installation/maintenance costs informed these decisions.
Custom air-handling units allow for a confi guration
optimized for reliable and fl exible use in varying Midwest
weather and facility operating conditions. For example,
dual prefi lter locations were specifi ed to allow the prefi
lter to be moved after the energy recovery wheels in
the winter, allowing the wheels to melt snow before an
intake fi lter becomes plugged. This design feature proved
advantageous when freezing fog conditions occurred
in January 2021, which avoided a system shutdown that
would have otherwise occurred due to plugged fi lters.
All laboratory air-handling units have multifan arrays,
sized for operation with one fan offl ine for redundancy.
This has been valuable during start-up issues with
motor failures, and it also benefi ts normal operation by
allowing lower fan speeds to reduce fan energy.
The project received the maximum $200,000 design
incentive from Wisconsin's utility " Focus on Energy "
program, which shortens the payback of energy conservation
measures from a 6.5-year simple payback to a
6.1-year simple payback.
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ASHRAE Journal - September 2022

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