White Paper

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Adaptive Cooling Technology uses three operating modes:
• In free-air mode, the module uses outside air for equipment cooling.
• In DX assist mode, DX units reclaim exhaust (warm) air to mix and re-circulate with outside air.
• In full DX mode, DX units provide full cooling by re-circulating and dehumidifying all inside air.
Figure 7 shows the airflow of each operating mode and the PUE that each can achieve.
Figure 7: This illustration shows airflow for the HP POD 240a.
Adaptive Cooling Technology intelligently adjusts to the most efficient operating mode for maintaining the cooling
parameters you set. A typical daily routine would be for the system to use free-air mode in the morning when it is cooler
outside, and then automatically switch to DX assist mode as the day gets warmer. In the afternoon when the outside
temperature is hottest, the system would switch to Full DX mode. When the weather gets cooler in the evening, Adaptive
Cooling reverses the process.
While you can get the best PUE with free-air mode, even full DX mode can yield a PUE of 1.3. That is far better than the
2.0 to 2.4 PUE that traditional facilities try to achieve.
Free-air mode air flow
DX assist mode air flow
Full DX mode air flow
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