Rack-Based Cooling Solutions

The Rack-Based Cooling approach takes the concept of Row-Based Cooling one step further and places the air conditioner and humidifier appliances in close proximity to the IT devices to be cooled. By being in close proximity and, therefore, dedicated to a single rack of equipment, the rack-oriented airflow paths are even shorter and exactly defined, so that airflow are totally immune to any installation variation or room constraints. All of the rated capacity of the CRAC can be utilized and the highest power density (up to 50 kW per rack) can be achieved.

Similar to row cooling, the rack-oriented architecture has other unique characteristics in addition to allowing extremely dense rack designs. The reduction in the airflow path length reduces the CRAC fan power required which increases efficiencies.

A rack-oriented design allows cooling capacity and redundancy to be targeted to the actual needs of a specific rack so a mixture of rack and blade server cabinets is ok within a single row. The biggest problem with this approach is that it requires a large number of air conditioner devices and associated piping when compared to other approaches. It also is typically more expensive to deploy the rack-specific hardware.

Rack-based cooling designs typically use chilled water or refrigerant as the cooling medium. However, the majority of product designs don’t actually deliver the liquid into the cabinet but into a separate enclosure or cooling device integrated into the rack design. The equipment itself is still air cooled.

As with row-oriented architectures, there are a number of side benefits other than cooling performance for rack-based designs:

• The reduction in the airflow path length reduces the CRAC fan power required, increasing efficiency.
• A rack-oriented design allows cooling capacity and redundancy to be targeted to specific racks.
• Rack-based cooling allows a data center, computer room, or server room to be implemented without a raised floor.
• In-Rack cooling allows for varied room designs and constraints. For example, load-bearing supports can be managed at the row level rather than trying to handle at the room level.