Four Ways to Cut Data Center Power Consumption
A few small changes can save data centers big bucks on energy consumption, cutting bills by 25% or more, says Samuel Graves, Chief Data Center Mechanical Engineer at consulting engineering firm Glumac. Graves lead an effort to rework the data center at online brokerage Scottrade Inc.
It's not just old data centers that can benefit from these tips: Scottrade cut its power requirements by 8% by making some simple changes in a state of the art data center it had just finished building the year before. In fact, it actually saved energy by allowing hot aisles to run hotter -- something that might sound counterintuitive to many seasoned administrators.
If you want to know the details of the work Graves did for Scottrade in Scottrade turns up the heat.
But if you want to cut to the chase, here are four tips that Graves says everyone who manages a data center should consider.
1. Seal holes in raised floors
It is very common to see very large holes cut under the power distribution units and racks to bring power and cable to the racks," says Graves. That affects air pressure in a raised floor, creating huge inefficiencies. "I did an evaluation of a large data center a couple of years ago," says Graves. When those holes were sealed, the client was able to shut down eight CRAC units, as they were no longer needed for cooling."
2. Add blanking panels
It sounds simple, but many data centers haven't taken this boring but critical step. Unless all vacant slots in a rack are sealed in this way, air from the hot and cold aisles will mix instead of moving through the rack from the cold aisle to the hot aisle as it should.
3. Think before you tile
"Almost always the perforated tiles in the cold aisle are set up with an architectural appeal in mind and not the actual server load," says Graves. It may look nice to have those perforated tiles neatly spaced and aligned, but it creates imbalances between the air provisioned and the actual head load in the racks. Improper placement of perforated tiles is a major culprit behind cooling problems in data centers.
4. Do a full assessment
It's hard to know exactly where to place those perforated tiles if you don't know what your cooling requirements are in each row and for every rack. Consider hiring an engineering firm to create a basic computational fluid dynamics (CFD) model of your data center. These models can be used to identify problem areas and to design the proper fix. According Graves, the cost to model a large data center such as Scottrade's typically comes in at about $1.50 per square foot. Tuning and optimizing the model adds another $.50 per square foot. "This is a generalization on cost and obviously, the larger the data center, the lower the per square foot cost," he says.