Vertiv Liebert XD Series, System Design Manual

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Figure 3.5 Liebert XDO placement over cold aisle
Table 3.4 below can be used to determine the correct number and spacing of Liebert XDOs.
Input Information Step Result
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/Liebert DS unit sensible
capacity, kW
D
E Required Liebert XD system cooling capacity, kW = C – D
F
Number of Liebert XDO20s required = E ÷ 20, rounded up (60Hz)
Number of Liebert XDO20s required = E ÷ 16, rounded up (50Hz)
G
Number of Liebert XDP/Liebert XDC units required = F ÷ 8, rounded up (60Hz
and 50Hz)
Room area, square feet H
I Area served by each Liebert XDO20 = H ÷ F
Spacing of cold aisles, center-to-center, typically 12-16 ft
(3.7 to 4.9m)
J
K Spacing between each Liebert XDO = (I ÷ J) - 2
L
Required Liebert XD system cooling density = E x 1000 ÷ H
OK if under 640; otherwise, additional cooling is required from Liebert Deluxe
or Liebert DS units.
Table 3.4 Calculating quantity and spacing of Liebert XDO modules (example below is Liebert XDO20)
3.9 Liebert XDR Module Placement
The Liebert XDR does not require a hot aisle/cold aisle arrangement for effective and efficient operation.
Refer to site-specific drawings for exact placement.
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