8 Chapter 2 Unit Positioning
Liebert.CRV Series Air Conditioner User Manual
Chapter 2 Unit Positioning
This chapter provides some ideas of typical installation of the Liebert.CRV unit(s), shows several examples of the
server room layouts and applications using Liebert.CRV units.
For best performances of Liebert.CRV is important to:
Reduce at minimum recirculation from hot aisle around the ends and/or over the top of the racks, prevent gaps
between the racks.
Reduce at minimum recirculation from hot aisle through server racks by using blanking panels.
Ensure cold air is being distributed across the front of all neighboring equipment racks by properly placed
Liebert.CRV unit(s).
Distribute load within the rack – it is generally advised to distribute the load as much possible uniformly across
the rack height, except for the rack closest to the Liebert.CRV unit, where it is suggested to have the higher
density load in the bottom and central part of the rack.
For more details refer to following details or contact Emerson Sales Representative.
1. Placement in the row of racks
For single row application with one Liebert.CRV unit it is not preferred to put the unit in the middle of the row because
of possible hot spots at top part of racks, unless in combination with CoolFlex or in application with more Liebert.CRV
units. The best approach is to place the Liebert.CRV at the end of the row, resulting into much better air distribution.
Please refer to the sample case study comparing the same server room with different Liebert.CRV position. The CFD
(Computational fluid dynamics) analysis results are shown in Figure 2-1 (height 1.8m off the floor for all following
cases).
Good approach:
Not advised approach:
End of row is preferred.
C
R
V
C
R
V
Figure 2-1 CFD analysis results of comparing the same server room with different Liebert.CRV position
2. Number of racks / length of the row
Standard application with one Liebert.CRV unit is with 2 ~ 6 racks. The exact number of racks depends on size of
Liebert.CRV unit used and heat load per rack. Whenever applying more than 6 racks for one CRV or heat load more
than 10kW per rack contact Emerson sales representative.
The CFD analysis result of one Liebert.CRV unit with 2 ~ 6 racks is shown in Figure 2-2.
