The challenges of increased data center density elevate the importance of the right cooling technology. This article discusses liquid and air cooling solutions in data centers and when each makes the most sense. It focuses on proven cooling technologies you can use right now, rather than emerging technologies. Data center provisioning is a multidimensional problem with a variety of constraints. Those constraints drive your choices, and choices need to be evaluated based upon a thorough analysis of each option’s total cost of ownership (TCO).

Increasing computer capabilities in data centers has resulted in corresponding increases in rack and room power densities. How to cool these new higher-powered racks is a question that challenges all data center managers. In the past, it was sufficient to roll in new servers and just add computer room air conditioners (CRAC units) around the perimeter. Not a lot of engineering was required.

When data centers were in the range of 75-100 watts per square foot (nominally square foot of total raised floor area), this method generally worked fine and the energy costs (and losses from inefficiencies) were small enough that they did not receive much attention.

However, today’s IT equipment can push data centers to 750 watts per square foot and the cooling challenges and costs are much more obvious. It is no wonder that at a 2007 Data Center Users Group meeting the 107 participants listed as their top three facility/network concerns: heat density (cooling), power density, and energy efficiency (energy costs and equipment efficiency).