Liebert® XDF Water-Cooled Product Application Guidelines
To ensure successful installation and proper operation of the Liebert XDF water-cooled unit, please adhere to
the guidelines below. If questions remain after reviewing these guidelines, please contact Emerson Network
Power, at 1-800-222-5877 to speak with an application specialist.
Application
Question
If water is used as
the coolant, what
type of system/loop
should be used?
Requirements
Liebert recommends employing
a closed-loop system (e.g. a
cooling tower).
Comments
This model employs a brazed plate condenser. A
closed water supply system protects the Liebert
XDF from particles and other contaminants that
might reduce cooling efficiency and damage the
XDF.
Will any external
piping be required
with this system and
what are the
requirements?
The unit will have to be
connected to a water source with
a flow of at least 15 gallons per
minute (GPM) through the
condenser to ensure the system’s
ability to operate at its full
capacity.
The correct piping size must be selected to
ensure proper flow. The installing contractor will
determine the appropriate piping size.
Can a water-based
coolant be used if
the building doesn’t
have a closed-loop
water source?
Yes, a drycooler and pump
package is available to create a
closed-loop split system.
The drycooler will require installation on a solid
surface (typically a concrete pad or roof; refer to
local code). Please reference the Liebert
Drycooler user manual (SL-10058) available at
www.liebert.com for additional detail.
If the drycooler and
pump package are
employed, how far
can the drycooler be
installed from the
Liebert XDF?
The distance between the Liebert
XDF and drycooler will be
impacted by the piping size and
number of bends. Utilizing 1¼”
L copper tubing, the drycooler
could be placed up to 150 ft
from the XDF.
The installing contractor will determine the
appropriate piping size and drycooler location.
What is an
acceptable coolant
temperature range
for the Liebert XDF?
A fluid temp between 50-85°F is
recommended. The unit is
designed for a maximum inlet
temp of 115°F, but temperatures
above 85°F will begin to reduce
the Liebert XDF’s capacity.
If glycol is desired, the percentage of glycol is
determined by the local winter ambient design
requirements. Please reference the Liebert XDF
user manual (SL-17010) available at
www.liebert.com for additional detail.
At what ambient
temperature can the
Liebert XDF operate
effectively?
The ambient temperature should
be between 35°F and 104°F.
Ambient temperature will affect the capacity of
the Liebert XDF. Temperatures above 95°F
begin to reduce the XDF’s capacity.
Liebert XDF Water-Cooled
Product Application Guidelines
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Liebert® XDF Water-Cooled Product Application Guidelines
Application
Question
Can the unit be
operated in a highhumidity
environment?
Requirements
The unit may be operated
anywhere from 20% RH to 80%
RH.
Comments
High humidity will impact the cooling capacity
of the Liebert XDF. Conditions with a dew
point above 60°F (31% RH at 95°F, or 60% RH
at 75°F) will begin to reduce the XDF’s sensible
cooling capacity.
How will condensate
be removed?
Condensate created via the
cooling process should be fed
into a gravity drain or pumped
away with an optional, factoryinstalled condensate pump.
The condensate pump will increase the distance
the condensate can be run from the unit to
approximately 30 horizontal feet and/or 12
vertical feet.
Should cable
entrances be sealed?
Yes, cables entrances should
always be sealed.
If cable entrances are not sealed, air infiltration
will adversely affect unit performance and allow
contaminants inside the cabinet.
What is the
minimum room size
in which the Liebert
XDF should be
operated?
The smallest acceptable room
dimensions based on 36” service
clearances on the side, top, front
and rear are:
• 10’D x 5’10”W x 9’10”H
• 574 cubic feet
The volume of the room will impact the back-up
ventilation time. Refer to the table on page 3 for
more information.
In what type of
environment can the
Liebert XDF be
operated?
Environments containing caustic
or explosive vapors are not
acceptable for this product.
The backup ventilation mode of the Liebert XDF
will circulate room air through the cabinet.
What equipment
heat load can this
unit accommodate?
The equipment load should be
between 3 kW and 14 kW.
Equipment load will also impact back-up
ventilation time. Refer to the table on page 3 for
more information.
What is the power
requirement for this
unit?
Two power connections are
required:
• 120/208V 3-ph (NEMA
L21-30P), and
• 120V 1-ph (NEMA 5-15P)
Please ensure 3-ph power (4 wires + ground) is
available to the room in which the Liebert XDF
will be located.
How much sound
will the Liebert XDF
make?
The sound level of the Liebert
XDF water cooled unit is 79
dBA (quieter than a fully
configured IT rack).
The water-cooled Liebert XDF has a lower
sound level than the self-contained, air-cooled
Liebert XDF (79 dBA compared to 86 dBA) and
is recommended for applications in which
people are working full-time in the same area.
How will I be able to
control and monitor
my Liebert XDF?
Liebert XDF comes standard
with an iCOM monitor and
control module.
An optional webcard can be ordered for remote
viewing and control via SNMP.
Liebert XDF Water-Cooled
Product Application Guidelines
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Liebert® XDF Water-Cooled Product Application Guidelines
Application
Question
What type of backup
power is
recommended to be
used with this unit?
Requirements
A true on-line, doubleconversion UPS is
recommended.
Comments
It is recommended that the Liebert XDF 1-ph
power connection be plugged into UPS backup
power to ensure the backup ventilation system
allows ample time for safe automated shutdown
of IT equipment in the event of an outage.
Backup Ventilation System
The back-up ventilation system in the Liebert XDF circulates room air through the XDF cabinet in case of a
power failure or interruption of cooling inside the XDF. The size of the room, the temperature of the room,
and the heat load inside the XDF all affect the amount of back-up ventilation time available.
The table below contains estimates of the time until the internal rack equipment reaches 95°F (with back-up
ventilation running and XDF cooling off).
Room Volume (Cubic Feet)
1,200
2,400
5,000
7,500
10,000
6 kW Load
2 minutes
4 minutes
8 minutes
12 minutes
15 minutes
10 kW Load
1 minute
2 minutes
5 minutes
7 minutes
9 minutes
14 kW Load
45 seconds
1.5 minutes
3 minutes
5 minutes
6 minutes
NOTE - The following assumptions apply:
• Liebert XDF controls and internal fans continue to run during back-up ventilation. This may require that
they be powered from a separate back-up power source. This back-up power source must have sufficient
run time.
• The temperature in the room is 75° F when back-up ventilation begins operating.
• No cooling is done by the building system during the back-up ventilation. If the building cooling system
continues to run during backup ventilation, the time to reach 95°F will be longer.
Additional Information
Additional information related to specifying, engineering, and installing a Liebert XDF cooling solution is
available in the following documents. The documents can be accessed at www.liebert.com by entering the
SL number listed below into the search bar:
• Liebert XDF User Manual, SL-17010
• Liebert XDF Guide Specification, SL-17015
• Liebert Drycooler User Manual, SL-10058
Liebert XDF Water-Cooled
Product Application Guidelines
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