Emerson Liebert Xtreme Density - Manual (Page 23)

Designing a Liebert XD Solution
17
3.7 Liebert XDV Unit Placement
Liebert XDV units should be placed on top of the cabinets that generate the greatest amount of heat.
If heat loads are dispersed evenly throughout the room, the Liebert XDV modules may be spread out
accordingly.
The Liebert XDV must be placed toward the front of the equipment cabinet, so that its front bottom
edge is flush with the front top edge of the cabinet. Placing the unit farther back on the top of the unit
will restrict airflow into the cold aisle. Placing the unit farther to the front will decrease the amount
of hot air drawn into the unit.
Figure 16 Positioning Liebert XDV on top of cabinet
Both of the Liebert XDV’s power cords should be connected to power sources. If only one power source
is available, then only the power cord labeled “SECONDARY” should be connected to the power
source.
Piping for the Liebert XDV is routed upward to the main return and supply pipes to and from the Lie-
bert XDP/Liebert XDC.
Table 4, below, may be used to determine the correct number of Liebert XDV modules.
Table 4
Determine required number of Liebert XDV modules (example below is Liebert XDV10)
Input Information Step Results
Total heat load in the room, kW A
Reserve capacity needed
(10% to 25% of A is
recommended)
B
C Required cooling capacity, kW = A + B
Existing/planned Liebert
Deluxe/DS sensible capacity, kW
D
E Required Liebert XD system cooling capacity, kW = C – D
F
Number of Liebert XDV10 modules required = E ÷ 10, rounded up (60Hz)
= E ÷ 8, rounded up (50Hz)
G
Number of Liebert XDP/Liebert XDC modules required = F ÷ 16, rounded
up (60Hz and 50Hz)
Room area, square feet H
I Area served by each Liebert XDV10 = H ÷ F
L
Required Liebert XD system cooling density = E x 1000 ÷ H
OK if under 580 for 12-foot cold aisle spacing
OK if under 435 for 16-foot cold aisle spacing
Otherwise, additional Liebert Deluxe or Liebert DS unit capacity is
needed.
INCORRECT
Liebert XDV
hangs over front
edge of rack
INCORRECT
Liebert XDV is
too far from front
edge of rack
CORRECT
Liebert XDV is flush with
front edge of rack
X
Liebert XDV is suspended
from ceiling structure...
X
... .the separation
between the rack and
the Liebert XDV
should be held to
less than 1" (25mm).
If this is not possible,
an air blocker should
be added to prevent
unwanted airflow
between the hot aisle
and the cold aisle.