When recently interviewed for a magazine article, I was asked about Green initiatives by data center operators. There are lots of innovative techniques for reducing power consumption in data centers, and lots of ways to apply renewable resources. The fact of the matter is that for the data center operator, some of the options are compelling, some are possible but not very compelling, and others are compelling but not reasonably possible.
In another recent post for example, we talked about wind power for data centers. The proper confluence of geographical location, local codes, local weather conditions, and available space are all constraining factors in the consideration of wind and solar power at the capacity necessary for anything other than a very small data center (not to mention that the payback period on investment in this sort of technology tends to be very long).
A data center operator needs options that will reduce energy costs without having to rebuild the site infrastructure, and without disrupting the operational models that are in play for the Customers of the space. For most asked this question, there are a handful of techniques that fall into the low hanging fruit category.
The first of these is the notion of raising the air temperature on the payload floor. Last year, ASHRAE issued new recommendations that give clearance to raise controlled air temperature to 80 degrees F. This could be a huge efficiency savings and could potentially increase the operational life of air conditioning equipment. In many data center organizations, this seems to be a social engineering change, requiring convincing of those accountable for the operation of the IT equipment. While there are cases that indeed justify not raising air temperatures to this level, we think that time will erode many of the hurdles that exists in this regard, and we’ll soon see higher air temperatures as the norm.
Air-side economizing is the technique by which one pulls in cold air from outside of the data center to supplement the cold air produced by the air conditioning equipment. The trick is though, that the air has to be cool enough (and sufficiently dry), for a long enough period of time, in order for the approach to be effective. Air side economizing isn’t something you’d see used in Atlanta or Dallas. It might be a great option in Buffalo or Minneapolis. This technique is enjoying some momentum. Coupled with a raising of the air temperature as suggested above, it might be applicable in even more locales than is otherwise the case.
Another technique is containment of either the hot or cold aisle to reduce mixing of cool and warm air. There are some very low cost ways to accomplish this, but the physical characteristics of the data center space will determine what is possible and to what degree it will be effective. Some operators have installed plastic sheeting, much like what is seen at cold weather loading docks or refrigerated rooms. This has demonstrated to be effective, but many organizations have resisted adoption of the technique over aesthetic reasons.
If you’ve had any successes with the techniques mentioned above, we’d love to hear your comments. We’d also welcome other good ideas you may have about Green techniques for data center operators.