Rear-door heat exchanger performance

This information describes the performance of the rear-door heat exchanger.

An example of expected performance of the rear-door heat exchanger is illustrated in Figure 1 for a typical inlet air temperature of 24 °C (75.2 °F), with a fully populated rack near uniform power dissipation, 32 kW heat load, and the node fans running near nominal fan speed (1530 cfm). By selecting the water inlet temperature and water flow rate, you can estimate the indicated heat removal. These levels can be achieved with normal cable exits from the rack and with a small amount of hot air bypass at the base of the door (small amounts of hot air might escape from the rack without being cooled by the door).

This figure illustrates a typical performance of a rear-door heat exchanger, 32 kW heat load — Figure 1. Typical performance of a rear-door heat exchanger, 32 kW heat load . Percentage heat removal as function of water temperature and flow rate. (24°C rack inlet air, 32 kW rack load, 1530 cfm air through the rear-door heat exchanger)

Water temperatures below 18°C (64.4°F) can be used only if the system that is supplying the water is able to measure the room dew point conditions and is able to automatically adjust the water temperature.

Another example of performance data is shown in Figure 2 for identical conditions as in Figure 1, except reflecting 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.

This figure illustrates a typical performance of a rear-door heat exchanger, 20 kW heat load — Figure 2. Typical performance of a rear-door heat exchanger, 20 kW heat load. Percentage heat removal as function of water temperature and flow rate. (24°C rack inlet air, 20 kW rack load, 1530 cfm air through the rear-door heat exchanger)