Emerson Liebert Economizer Solutions Fiche De Données

Page de 8
Fluid-Side Cooling Economization Strategy
Fluid-side economizers work in 
conjunction with a heat rejection loop 
− consisting of either a cooling tower, 
evaporative cooler or drycooler − to 
satisfy cooling requirements. 
These systems are incorporated into either 
a chilled water or glycol-based cooling 
system. For economizer operation, the fluid 
used in the cooling system passes through 
an additional heat exchanger to cool the 
room air, reducing or eliminating the use of 
cooling compressors and pumps. 
Energy-efficient Liebert technologies 
are well suited to fluid-side cooling 
economization.
4
How the liebert glyCool system Works
The self-contained Liebert GLYCOOL system comprises a compressorized Liebert glycol 
system with advanced controls, a standard cooling coil, an additional “Econ-o-coil” free 
cooling coil and a drycooler. 
At ambient temperatures above the CRAC return temperature (less the drycooler 
approach), the system functions as a normal glycol-cooled system. As outdoor 
temperatures drop, the temperature of the fluid in the heat rejection loop drops also. 
Once it is cold enough outside, the control opens the modulating valve to the Econ-o-coil 
circuit. Depending on ambient conditions, the system either reduces or eliminates cooling 
compressor and pump operation.
savings 
The Liebert GLYCOOL system delivers an average annual energy savings of 20–50%.
GLYCOOL Cooling 
for Liebert DS
TM
 and Liebert Challenger
TM
 3000
liebert glyCool system
Providing free cooling by using outside air through the Econ-o-coil circuit to maximize cooling 
efficiencies
Econ-o-coil rests 
on A-frame coil
Glycol-cooled 
condensers
and Paradenser 
tubes
A-frame coil inside
Compressors
Centrifugal 
blower
Liebert 
Drycooler
Glycol 
circulating 
pump