ASHRAE Journal - June 2019 - 46

2019

ASHRAE TECHNOLOGY AWARD CASE STUDIES

cooled using the chilled water generated by the water
to water heat pumps whenever required to transfer the
condenser heat to the thermal loop.

the building's low temperature (104°F [40°C]) glycol
loop, on which the center's efﬁcient design is primarily based. The loop is fed with heat by the heat
pump condensers as the ﬁrst stage of heating and
Energy Efﬁciency
then by the condensing boilers as the second stage.
The building chillers'/water to water heat pumps,
Excess heat is removed from the loop through the dry
a dry cooler and condensing boilers are connected to
coolers.
Chillers operate year-round to
meet the building's cooling needs.
In winter, when the cooling load is
reduced and limited mainly to air
conditioning internal zones, the
chillers operate in heat pump mode
to transfer heat from internal areas,
processes and exhaust air to the
thermal heat loop. The main sources
of heat recovery are the toilet and
general exhaust, the electrical room,
the server room, the elevator room
and the heat rejection of the refrigeration compressors in the walk-in
freezer and the trash room.
The administrative area is heated
and air conditioned by a variable volume rooftop unit serving variable air
volume (VAV) boxes and fan power
mixing boxes (FPMB) in the zones.
The perimeter zones are heated by
hot water coils installed in the duct
Electrical bearing damage
Protect motor bearings with
AEGIS® Shaft Grounding Rings
causes unplanned downtime
after the VAVs/FPMBs. Elsewhere,
By channeling VFD-induced discharges
VFD-induced electrical discharges
heating and cooling are mainly done
safely to ground, AEGIS® Shaft
can blast millions of pits in metal
Grounding Rings prevent electrical
by single coil fan coil units with sixbearing surfaces. These discharges
bearing damage. Proven in millions
burn and contaminate bearing grease,
way valves that circulate either hot or
installations worldwide, they provide
drastically reducing its effectiveness.
unmatched protection of motors and
chilled water as needed. The selection
They also result in bearing fluting
coupled equipment from electrical
failure and costly, unplanned downtime
of low temperature heating coils probearing damage, motor failure, and
- often in as little as 3 months!
unplanned downtime.
motes the effectiveness of condensing boilers and maximizes the use of
recovered heat.
Download a free copy
of the AEGIS® Bearing
Kitchen hoods are equipped with
Protection Handbook:
intelligent control to modulate the
www.est-aegis.com / hvac
evacuation and supply of fresh air
Fluting Damage
depending on the cooking activities.
Visit us at
Opacity and temperature sensors
EASA 2019: Booth 824
are installed in the hoods. The hood
exhaust fan and the kitchen fresh
1-866-738-1857 | sales @ est-aegis.com
air intake system are equipped with
variable speed drives.

VFD-Induced Bearing
Currents Kill HVAC Motors!

ASHRAE JOURNAL

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J U N E 2 0 19

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ASHRAE Journal - June 2019

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