ASHRAE Journal - December 2020 - 50

2020

ASHRAE TECHNOLOGY AWARD CASE STUDIES

to a neighboring large classroom
FIGURE 2 HVAC system schematic.
building. The building has a total of
three mechanical rooms for ease of
maintenance. The mechanical rooms
are divided up to house the central
Chilled and Hot
plant providing hot and chilled water
Water Pumps
Hot Water
to the building, the 100% outdoor
Reheat Coils
air lab air-handling unit, and the
Air
recirculation space-conditioning
Handler
Air Handler
No. 1
air handler. Equipment clearNo. 2
ances, owner walkways, work areas,
Modular Heat Domestic Hot Water
and equipment grouping were all
Recovery Chiller
designed to provide the user with an
Closed Circuit
Fluid Cooler
Boilers
easily maintainable system. Building
Source/Sink Pumps
commissioning was completed on
this project and played an essential
gas usage, with a cost of $3,711, resulting in a total utility
role in reviewing the envelope, testcost of $125,819.20. Compared to the I2SL database, this
ing the emergency generator and interaction with
building saves approximately $480,926 in annual utility
lab HVAC, and reviewing building pressurization. A
costs, compared to a similar laboratory building.
blower door test was performed on the building to test
the envelope and building's ability to maintain presEnvironmental Impact
surization; the building passed this test, according to
The building energy usage is approximately 300%
criteria established by the commissioning agent. While
more efﬁcient than the average lab, compared to the
the system did pass the building pressure testing, the
Department of Energy database, and 400% more efﬁbuilding experienced higher humidity than initially
cient than the Labs21 database. The BCTC Newtown
anticipated.
Campus Science Building generates approximately
Thermography was used to identify an inﬁltration
865 metric tons of CO2, compared to an ASHRAE/IES
issue around a louver on the third ﬂoor of the building
Standard 90.1-2010 baseline building, which produces
that was generating humidity issues in lab spaces. The
1390 metric tons of CO2, and 3275 metric tons according
engineering design team optimized the facility during
to the I2SL database.
post-commissioning and reduced the energy usage by
An exhaust dispersion and re-entrainment study
an additional 12.5%, from an average monthly EUI of 7.57
was performed for this building to assist in proper
down to 6.63-a savings of $17,712 annually.
placement of exhaust and intakes for the 100% lab airCost-Effectiveness
handling unit and recirculation air-handling unit. The
The system selection was based upon life-cycle costing position of the intakes for outside air was reviewed for
and the owner's ability to maintain the system. While the appropriate relationships to laboratory exhaust, ﬂues,
ﬁnal selection did not appear to be the most efﬁcient, it
and surrounding building air discharges based upon
was the most efﬁcient within project budget. A geotherthe actual chemicals that would be used. A compumal well ﬁeld was also analyzed, but it was proven to not tational ﬂuid dynamics model was created to model
be feasible due to budget constraints. The use of dual
these conditions, and a list of recommendations was
occupancy sensors to control ventilation air in place of a provided. The design team reviewed
more complex CO2 system was a cost-effective approach this and provided modiﬁcations to
to provide demand-controlled ventilation.
the design to reduce the environmenThe most recent annual review of utility bills shows a
tal impact and improve the indoor
yearly electrical cost of $122,108.20, which accounts for
air quality, while maintaining a safe
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82% of the building's energy usage. The remaining 18% is indoor environment.
50

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ASHRAE Journal - December 2020

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