ASHRAE Journal - January 2023 - 50

TECHNICAL FEATURE
FIGURE 6 (From left) Inspection of electrical submeter, IEQ survey being conducted, electrical
switchgear checking and meter calibration.
related to the HVAC system. The data recorded
by the DDC can be updated at the rate of
four times per minute to enable the HVAC
system to achieve faster and better control
requirements.
Energy Audit Process
Level 1 Energy Audits, compliant with
Cooling towers (Figure 5, page 49), connected to the
building chillers, are equipped with two-speed motors
controlled by the BAS. The two-speed motors are
adjusted based on the needed cooling water temperature
at adjustable setpoints established by the BAS for
the building.
Two airside system primary AHUs precondition the
outdoor air supply to the building. The treated outdoor
air is delivered to the AHU at each floor, then distributed
to zone variable air volume (VAV) boxes followed by fan
powered terminal units (FPTUs).
Additionally, the building's concrete structure with
low-e curtain glazing for exterior windows (Figure 6)
minimizes building heat loss in the winter and building
heat gain in the hot humid summer, as is attributed to
being in Climate Zone 3A.
The BAS monitors and controls the chillers, AHUs,
primary air-handling units (PAUs), VAV boxes, public
fan coil units (FCUs), FPTUs, exhaust fan, plumbing and
lighting serving the whole building. The BAS monitors
and control panels are located inside a security control
room that is operated 24 hours a day, thus under
continuous monitoring and supervision. All systems
are operated under preset time schedules for start-up
and shutdown and keep continuous monitoring on the
device temperature, flow pressure and airflow. Half of
the office area on every floor, comprising nine zones,
is using a direct digital control (DDC) associated with a
building management system (BMS) interface to manage
the overall control. The DDC can fully accommodate
the control points and programs of devices at all floors
and accelerate the processing speed of the parameters
50
ASHRAE JOURNAL ashrae.o rg
J A N U A RY 2023
ASHRAE/ACCA Standard 211-2018, Standard
for Commercial Building Energy Audits, were
conducted in 2013 and 2021 to acquire a full
picture of the building's energy performance
prior to and after energy conservation measure
implementation. An ASHRAE Certified
BEAP led the 2021 audit to monitor and supervise
the implementation of the energy conservation
measures (Figure 6).
As the audit was conducted during the COVID-19 pandemic,
special arrangements for health and safe entry
requirements to the building included proof of " green "
health code, body temperature check and wearing of
face mask. Due to social distancing and occupant limitation
requirements, the audit team was limited in the
number of active personnel who could carry out the
work.
Furthermore, maintaining social distancing during
the energy assessment inside the building's mechanical
and electrical rooms, as well as restricted spaces in
this 40-story high-rise facility with different types of
evaluation and measurement systems, posed challenges
throughout the process.
To confirm that indoor environmental quality is not
compromised for energy savings, review of IEQ figures
for office spaces by on-site measurements with the following
international standards were used.
1. ASHRAE Standard 62.1-2013, Ventilation for Acceptable
Indoor Air Quality, for reviewing minimum fresh airflow
rate and CO2 concentration.
2. ASHRAE Standard 55-2013, Thermal Environmental
Conditions for Human Occupancy, for reviewing thermal
comfort including results of temperature and relative
humidity measurement.
3. ASHRAE Standard 52.2-2007, Method of Testing General
Ventilation Air-Cleaning Devices for Removal Efficiency by
Particle Size, for reviewing the rating of MERV filtration
media.
4. CIBSE. 2012. SLL Code for Lighting. CIBSE.

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ASHRAE Journal - January 2023

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