ASHRAE Journal - February 2020 - 70

COLUMN IEQ APPLICATIONS

FIGURE 3 The UPSS software dashboard displaying individual energy (plug load) consumption and scheduling, environmental levels and preferences.

design involves the occupancy positioning system (see
below) within the zones that detect the actual number
of occupants to provide accurate outdoor airflow in
compliance with ASHRAE Standard 62.1 and Singapore
Standard SS554.

PoE Lighting and Active Use of Daylight
The central lighting system utilizes ultra-low power
LEDs powered by Ethernet instead of normal power
cables, which is expected to save up to 30% of lighting energy. A total of 53 PoE lights were installed in
a closed-loop design configuration to ensure light is
delivered into the space to achieve a minimum level
of light that is uniformly distributed on desk level
surfaces (Figures 1 and 2). Since this light can originate
from either artificial or natural sources of illumination, active use of daylight in the space is designed
to reduce the reliance on electrically powered lights
and thus save more energy. Conversely, should the
incoming daylight excessively exceed the target light
level, a feedback signal will be sent to the roller blinds
to reduce the harsh light received on the surface.
These controls are also programmed so that when the
light is below the target level, the roller blinds will
be retracted (Figure 3). Because of the high degree of
control over many important lighting parameters, the
SinBerBEST team has been able to develop and test the
lighting controls under a wide range of conditions in
a relatively short period of time. Additionally, should
occupants prefer a more personalized lighting level on
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ASHRAE JOURNAL

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FEBRUARY 2020

their desks, they can rely on task lighting or request
more lighting using the UPSS.

Occupancy Positioning System (OPS)
Currently, many buildings are incapable of detecting
occupancy causing energy waste by providing services to
empty rooms. With the pervasive and wide availability of
Wi-Fi infrastructure and use of Wi-Fi module equipped
mobile devices, we have developed an international
award winning OPS system for indoor context-aware
services and location-based services (Zou et al, 2017).
This cost-effective OPS system not only knows how
many people are present but also knows their identity
and indoor service preference in a totally non-intrusive
manner. Novel localization algorithms empowered
by advanced signal processing and machine learning
methods are used to overcome device heterogeneity,
system robustness, environmental dynamics and signal
feature selection. A total of nine software upgraded commercial off-the-shelf Wi-Fi routers are installed in the
space to overhear existing Wi-Fi traffic and accurately
retrieve data. The OPS allows the building to provide the
right and personalized level of plug load, lighting, air
movement and air conditioning service only where it is
needed and at the required level.

Plug Load Monitoring and Control and User-Personalized
Space Setting (UPSS) Software
The task of plug-load reduction has been difficult because of the limited understanding of energy
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ASHRAE Journal - February 2020

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