The enterprise and colocation data center operators are infused with a risk adverse culture. In most aspects, this is a prudent philosophy, especially when it comes to ensuring IT power, which essentially is a binary condition; you have it or you don’t. Assuming you have made the decision to have whatever level of redundancy or seeking to maintain power availability, the second concern is energy efficiency. Clearly, UPS technology has made great strides and now are available with operating energy efficiencies in the 95% and above ranges at full load, and still remaining relatively efficient operation profiles even when under low per unit loads encountered in highly redundant designs such as N+1, 2N, or even 2(N+1). So while there is always room for improvement, it seems we are only going to be able to squeeze out a few more points of electrical efficiency.
As you may have guessed by now, this article is about cooling. In most cases, if we’re going to discuss energy efficiency, conventional cooling systems (i.e., closed loop CRAC/CRAH units in the whitespace) have traditionally used a substantial portion of energy consumed by the facility infrastructure. This is especially true in older data centers, resulting in a PUE of 2 or higher. And while newer cooling equipment and better practices regarding airflow management have improved this situation, cooling still represents a substantial portion of facility energy usage.