Vertiv Liebert PDX - Liebert PDX EconoPhase System Description; System Overview and Components

1
Liebert
®
PDX, EconoPhase Version - UM - 265133 - 29.08.2019
1 - Liebert
®
PDX EconoPhase
System description
1.1 - Liebert
®
PDX EconoPhase System
Liebert
®
PDX EconoPhase System is designed to provide
precision air conditioning to computer racks in a data center or
computer room as e󰀩ciently and e󰀨ectively as possible.
A Liebert
®
PDX EconoPhase System is composed of:
• Liebert
®
PDX EconoPhase version - High E󰀩ciency, Digital
Scroll, oor-mounted indoor unit
• Liebert
®
MC™ Condenser EconoPhase version - Air-cooled
microchannel condenser, premium version
• Liebert
®
PDX EconoPhase - Liebert
®
PDX EconoPhase
pump refrigerant module
The Liebert
®
PDX EconoPhase is an add-on module for use with an
air-cooled Liebert
®
PDX system. The Liebert
®
PDX EconoPhase
will allow the system to switch to Liebert
®
PDX EconoPhase
operation when the outdoor temperature is low enough to provide
the required temperature di󰀨erence between the inside air and the
outside air, providing signicant energy savings because there is
no need to operate the compressor. At lower temperatures, the
system switches one or both circuits from Compressor Mode to
Pump Mode. The pump consumes roughly 1/10th of the power
consumed by the compressor.
The Liebert
®
PDX EconoPhase system maintains this energy
e󰀩ciency by employing the heat absorption properties of a liquid
(pumped refrigerant) through a phase change. Refrigerant is
pumped as a liquid, becomes a gas within the Liebert
®
PDX
evaporator and then is returned to the Liebert
®
MC where it
condenses to a liquid. The subcooled liquid refrigerant from the
condenser is then run directly into the Liebert
®
PDX EconoPhase
pumps and is circulated back to the Liebert
®
PDX unit (see Figure
1). The system will operate as a typical air-cooled direct expansion
system when outdoor ambient conditions are unfavorable
to EconoPhase operation. The pumps in the Liebert
®
PDX
EconoPhase pump module are turned o󰀨 and bypassed during
compressor operation.
Condenser (Pump Mode)
Condenser (DX Mode)
Indoor Unit
ropaVxiM ropaV/diuqiL
Liquid
Pressure
Enthalpy
Tradtional Vapor Compression Cycle
EconoPhase Cycle
Fig.1 - Pressure enthalpy diagram, pumped refrigerant Liebert
®
EconoPhase