In-row cooling can be a highly efficient cooling approach for multiple reasons, but there is one common objection that sometimes gets in the way of its adoption. That common barrier is that data center managers sometimes believe existing facilities can’t be reconfigured for in-row cooling.
“The number one roadblock we run into with in-row cooling solutions is that data center operators say, ‘we just can’t split up our current server deployment to reconfigure for in-row cooling,” said Jesse Cefalu, a cooling business development specialist with Schneider Electric. “They think, ‘we just can’t do a shut down of all our systems to rearrange our racks and put the cooling units in.’”
The problem with this thinking, said Cefalu, is that in-row cooling doesn’t have to be a big bang deployment. It can be phased in at mature data centers, often by planning each phase to coincide with other changes, such as plans for new servers or cabinets. “We can take a phased approach, and help them plan for that,” he said.
Ironically, it’s often existing, older data centers with perimeter cooling that would benefit from in-row cooling the most, said Cefalu. Perimeter cooling installations that use raised floors to supply cool air sometimes grow inefficient over time as more racks, servers, or cooling units are installed, and wiring or piping underneath the raised floor is added without proper attention to good air flow.
Another challenge is the growing power density of today’s information technology (IT) loads. Whereas 10 to 12 years ago, a fully populated rack might use two or three kilowatts (kW) per rack, today, 5-15kW per rack is fairly common. This is where one of key benefits of in-row cooling comes into play, said Cefalu, since the cooling units are right within the rows, directing cool air right to the loads, which slashes the distance air (both cool and warm air) needs to travel.
This form of precision cooling more effectively isolates and “neutralizes” warm air exhausted from the backs of rows, rather than a perimeter cooling where there is a tendency for more air mixing, said Cefalu. Additionally, in-row cooling uses a hot aisle, cold aisle configuration that is ideal for containment features which further reduce air mixing and have strong payback, especially with denser IT loads.
Another key benefit of in-row cooling, said Cefalu, is that these units can be deployed with an economizer mode that uses cool, outside air to support cooling, which allows components like chillers and compressors to be shut off or operated at a reduced capacity. While an economizer mode may add to upfront cost because there might be some additional piping, they save substantial energy costs on cooling—50 percent or more, depending on the climate.
Resellers looking to provide return on investment (ROI) insights regarding in-row cooling should take advantage of the appropriate TradeOff Tools accessible on Partner Central. For example, there is a “Cooling Economizer Mode PUE Calculator” tool that examines the impact of geography and cooling mode on power useage effective, energy costs, and carbon emissions.
Another TradeOff Tool—Data Center Efficiency Calculator—examines the impact of alternative cooling approaches, including energy costs. This tool has drop down menus that let users see the impact of cooling and air distribution choices. Another TradeOff Tool examines in-row containment. For resellers or customers wanting a more detailed discussion of when in-row cooling is desirable, white paper 130, “Choosing Between Room, Row, and Rack-based Cooling for Data Centers,” is a good primer, said Cefalu.
Being adept at using TradeOff Tools to present ROI numbers is vital to positioning in-row cooling, said Cefalu. There may be instances were in-row is not the only viable option, or yet others it may be best to build or lease a new data center, but overall, he added, in-row cooling suits many existing data centers, even those that balk at the thought of reconfiguring their racks, or are focused on upfront costs.
“There are just so many benefits, from the way in-row cooling efficiently captures and neutralizes warm air from denser IT loads, to economizer mode, which once it pays for itself, goes straight the good of the operating bottom line,” said Cefalu. “It important to be able to help users establish ROI, assist them with deployment options, and just build off of the desire that operators have around running data centers that are more organized, efficient, and capable of handling high density loads.”