As data center operators struggle with high-density computing loads, cooling technologies continue to move closer to the processor. On Tuesday Emerson Network Power introduced a new cooling system that brings refrigerant-based cooling inside the server tray.
The Liebert XDS server cooling system consists of a standard-sized IT rack equipped with patent-pending cold plate server cooling technology from Emerson’s technology partner, Clustered Systems. The cooling plates are configured to use refrigerant supplied by a Liebert XDP refrigerant pumping unit.
System Shines in Chill Off 2
The Clustered Systems prototype made news earlier this month when its energy efficiency was showcased during the Chill Off 2, en evaluation of leading cooling technologies sponsored by Silicon Valley Leadership Group (SVLG) and conducted by Data Center Pulse and Lawrence Berkeley National Laboratory (LBNL). The 36-server rack from Clustered Systems showed energy savings of 12 to 16 percent compared to other cooling approaches, which used in-row and rear-door cooling units.
“The Liebert XDS is a major step forward in the evolution of data center cooling," said Steve Madara, vice president and general manager of the Liebert precision cooling business of Emerson Network Power in North America. "Cooling is now positioned at the most efficient spot – at the server that generates the heat. Heat is stopped at the source, so no additional heat is expelled to the room from the rack. This significantly minimizes the energy required for data center cooling. It has the possibility to reduce the total data center cooling energy to less than the energy consumed by the server fans that are removed.
“As a result, the Liebert XDS has the potential to fundamentally simplify the design of data centers,” Madara said. “With the elimination of the fans, data center managers no longer need to worry about managing airflow in the data center or employing a hot-aisle/cold-aisle configuration.”
The XDS is the latest in a series of products from Emerson Network Power that have gradually been focusing cooling power closer and closer to the servers. In 2003 the Liebert XD system brought refrigerant cooling to the top of server racks. In recent years Emerson has cold aisle containment and, in 2009 introduced the Liebert XDR rear door heat exchanger, which eliminated cooling system fans by using server fans to provide airflow through the rack.
Emerson: Can Manage Loads of 40 kW per Rack
With the Liebert XDS, heat generated by the server is transferred through heat risers to the server housing, then through the thermal interface material lining the cover, and finally transferred to a cooling plate, which uses refrigerant-filled microchannel tubing to absorb the heat, eliminating the need to expel air from the rack and into the data center. Emerson says the system can cool racks at up to 40 kW.
"The Liebert XDS solution fits perfectly into high-density environments and is ideal for data center managers updating existing Liebert XD systems, undertaking consolidation efforts or building new data centers," said Madara, who added that the XDS "actually consumes less power than 100 percent free-cooling that uses outside air, without any risks of limited operating hours” due to changes in the outdoor temperature.
The Liebert XDS uses standard 1U servers with modifications to the heat sinks, is available in 42U and 45U versions, and features 35 and 36 1U server slots with cooling plates designated for each slot. One single connection to the rack supports cooling plates for all internal servers.
