ASHRAE Journal - December 2021 - 45

FIRST PLACE | 2021 ASHRAE TECHNOLOGY AWARD CASE STUDIES
in early 2017 after chiller replacement. Comprehensive
air-conditioning waterside RCx methodology was
established following internal technical guidelines with
reference to ASHRAE Guideline 0.2-2015, Commissioning
Process for Existing Systems and Assemblies. Through onsite
investigation, meters and sensors are calibrated to
ensure data accuracy. An ambitious target to increase
the constant speed chiller plant COP to above 5.0 was
set, focusing on the chilled water and condensing
water circuit and the optimization of system effi ciency
through the addition or reduction of number of chillers
used during operation. The savings from the RCx of the
waterside system are verifi ed and refl ected in the following
section.
Building Performance
Energy data are collected in 2PP Offi ce and Mall to
monitor the consumption of different electrical and
mechanical systems, e.g., waterside and airside equipment,
lighting and small power (L&P), elevator and
escalator (E&E) and plumbing and drainage system. The
energy meters have more than 95% coverage of spaces
and are connected to the Internet of Things (IoT) framework
to upload real-time data to the data analysis tool
for storage and analysis.
Energy management opportunities (EMO) were identifi
ed based on the analysis of energy meter data and
operation data. Opportunities included the aforementioned
chiller replacement and RCx work as well as
water pump optimization, electronically commutated
(EC) plug fan installation, air-handling unit (AHU)
pressure and temperature reset, retrofi tting of lighting
system into LED fi xtures, installation of occupancy and
daylight sensors and elevator modernization. A 27.6%
energy reduction in 2PP Offi ce and 13.7% energy reduction
in 2PP Mall from 2015 to 2019 was realized. Both
2PP Offi ce and 2PP Mall outperform the EUI target of
ANSI/ASHRAE/IES Standard 100-2018, Energy Effi ciency
in Existing Buildings, and continuous monitoring and
energy saving strategies have been implemented to
further reduce the energy consumption and sustain the
performance.
Innovation
Big data analysis has been conducted with the building
operational data. Through the digital platform on
the cloud, the operation team can review the operation,
TABLE 1 HVAC system information.
HVAC WATERSIDE
SYSTEM
2PP Offi ce Tower, 2PP Mall, two hotels, and apartments share
a central chiller plant comprised of fi ve sets of seawater-cooled
centrifugal chillers with a total cooling capacity of 9,000 tons.
Condensing water from a common seawater pump house serves
various space uses.
HVAC AIRSIDE
SYSTEM
Air-handling unit provides adequate fresh air rate and suitable air
temperature.
VAV terminal box maintains zone air temperature.
TABLE 2 Energy saving achievements.
CHILLER REPLACEMENT:
Chiller annual energy consumption reduced by
4,844,922 kWh, equivalent to $875,212, or 28% reduction
Chiller plant COP improved from 3.3 to 4.8, or a 45%
increase in effi ciency
Chiller plant energy consumption reduced by
5,836,953 kWh, equivalent to $1,054,417, or 26%
reduction
RETRO-COMMISSIONING:
2PP Offi ce and 2PP Mall's energy consumption outperforms
the ASHRAE Standard 100-2018 baseline by 36.9% and
21.0%, respectively
Water transfer factor of chilled and condenser water pump
increased by 15%, equivalent to 531,663 kWh energy
saving, or $96,042
REAL-TIME IAQ MONITORING:
2PP Mall indoor average CO2 concentration is below 700
ppm, over 80% of offi ce areas achieve thermal comfort
under ASHRAE 55-2017, and exceedance on ASHRAE
Standard 62.1-2013 ventilation performance requirements
FIGURE 1 2018 building electricity breakdown.
22.81%
48.36%
12.61%
7.28%
1.92%
Waterside
Airside
Lighting and Small Power
7.02%
Elevator and Escalator
Others
Tenant
i.e., chiller plant performance, anywhere at any time.
Despite there being millions of data collected every day
in Pacifi c Place, the vast amount of data is of no value
without being analyzed. Manual analysis was found to
be ineffective given the large volume of data. Therefore,
D E C E M B E R 2 0 2 1 ashrae.o rg ASHRAE JOURNAL
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ASHRAE Journal - December 2021

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