Close Coupled Cooling

The goal of close coupled cooling is to bring heat transfer closest to its source: the equipment rack.

Air flows generally follow short and linear paths, reducing, in this way, the necessary power needed to start up the fans and increasing the energy efficiency.

The Closed-Loop cooling typologies act independently from the room they are installed; the rack and the heat exchanger work exclusively with one another, creating an internal microclimate.

Some cooling typologies can be associated to fans with variable velocity that adapt in better ways to the workload, so also to the internal temperature of the rack.

Having fans that work at the minimum velocity satisfying the requirements of the Data Center is very important for energy consumption.

The reason seems to be due to the fact that the In-Row solutions offer significant energy savings as the rack densities are close to the 8-10 kW threshold; today's average densities for medium-sized data centers are instead about 5 kW and energy savings do not fully justify the higher cost of investment for the cooling system.

In 2012 Google published a photo gallery that shows the design of its cooling system, followed by an explanation of Data Center Vice President Joseph Kava, of how it works.

In the data center shown the rooms serve as cold corridors, there is a raised floor but there are no perforated tiles.