IBM Rear Door Heat eXchanger V2, Installation And Maintenance Manual

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Performance data is shown in Figure 3 for a 20 kW heat load. Because of the lower
heat load, a specific level of cooling can be achieved with warmer water, a lower
flow rate, or both.
* As described in “Water-supply requirements for secondary loops” on page 13, a
given water temperature may be used only if the system that is supplying the water
is able to measure the room dew point and automatically adjust the water
temperature accordingly. Otherwise, the water temperature must be above the
maximum dew point allowed at that datacenter installation.
140
130
120
110
100
90
80
70
60
50
% heat removal as function of water temperature and flow rate for
given rack power, rack inlet temperature, and rack air flow rate
4 10 12 14
% heat remo
va
l
Water flow rate (gpm)
Water
temperature
12°C *
14°C *
16°C *
18°C *
20°C *
6 8
22°C *
24°C *
Airflow
(cfm) = 2000
Rack Power
(W) = 20000
Tinlet, air
(C) = 27
Figure 3. Typical performance of the heat exchanger, 20 kW heat load
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Rear Door Heat eXchanger V2: Installation and Maintenance Guide