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Rear Door Heat eXchanger V2

See this topic to learn about parts of ThinkSystem Rear Door Heat eXchanger V2.

Figure 1. ThinkSystem Rear Door Heat eXchanger V2 components

Table 1. Rear Door Heat eXchanger components
1 Rear Door Heat eXchanger assembly9 Hinge kit
2 Air-purging valve10 Lift handles
3 Air-purging tool11 Lift handle
4 Door latch12 Serial number
5 Latch plate13 Lift handle
6 Drain valve14 Lower air baffle
7 Return manifold coupling15 Upper air baffle
8 Supply manifold coupling 

Rear Door Heat eXchanger V2 specifications

  • Depth: 129 mm / 5.0 inches
  • Height: : 1950 mm / 76.8 inch
  • Width: 600 mm / 23.6 inch
WeightEmpty: 39 kg / 121 lbs
Air movementProvided by servers and other devices in the rack
Air temperature dropWith high-heat-load devices, up to 25°C (45°F) between the air exiting the rack devices and the air exiting the heat exchanger.
  • Source

    User-supplied, compliant with specifications in this document

  • Pressure

    • Normal operation: <137.93 kPa (20 psi)
    • Maximum: 689.66 kPa (100 psi)
  • Volume

    Approximately 9 liters (2.4 gallons)

  • Temperature

    • Above dew point
    • 18°C ±1°C (64.4°F ±1.8°F) for ASHRAE Class 1 Environment
    • 22°C ±1°C (71.6°F ±1.8°F) for ASHRAE Class 2 Environment
    See “Heat exchanger performance” for more information.
  • Required water flow rate (as measured at the supply entrance to the heat exchanger)

    • Minimum: 22.7 liters (6 gallons) per minute
    • Maximum: 56.8 liters (15 gallons) per minute

For setup and installation, see Set up Rear Door Heat eXchanger V2.

Heat exchanger performance

Expected performance of the heat exchanger is illustrated in the following figure for a typical inlet air temperature of 27°C (80.6°F), with a fully populated rack, near uniform power dissipation, and a 30-40 kW heat load. By selecting the correct water inlet temperature and water flow rate, you can achieve the necessary heat removal. A heat removal of 100% indicates that an amount of heat equivalent to that generated by the devices has been removed by the heat exchanger and the average air temperature leaving the heat exchanger is identical to that entering the rack (27°C /80.6°F in this example). Heat removal in excess of 100% indicates that the heat exchanger not only removed all of the heat generated by the devices but further cooled the air so that the average air temperature leaving the rack is actually lower than that entering the rack.

Figure 2. Typical performance of the heat exchanger, 30 kW heat load

As described in Water specifications for the secondary cooling loop, 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 that is allowed at that data center installation.

Performance data is shown in the following figure 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.

Figure 3. Typical performance of the heat exchanger, 20 kW heat load