Despite improved datacenter temperature technology from a decade ago many companies still face cooling problems which lead to wasted energy of datacenters. Ten common issues that lead to energy wasting include: 


Phantom Leakage, Perforated Tiles, Unsealed raised-floor openings, poor rack sealing, poorly calibrated temperature and humidity sensors, CRACs fighting for humidity control, too much cooling, empty cabinet spaces, inefficient rack layout, not using cooling management at all.

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Ten Most Common Data Center Cooling Mistakes - Data Center Knowledge