What is cabinet level containment and how does it impact datacenter airflow?
Cabinet-level containment is a practice of separating hot and cold air from within the cabinet itself, as opposed to the aisle or room as a whole. Cabinet-level containment can be more cost effective for new construction and easier to implement into legacy applications.
For new construction, cost savings can be realized by incorporating containment into the data cabinet, reducing or eliminating the need for on-site construction and project management.
In legacy data centers, the data center team can switch to deploying chimney cabinets at any time and create new, higher density areas in just about any data center. Going back an retrofitting existing cabinets with chimneys is usually not feasible, but a switch to chimney cabinets is possible in a majority of existing data centers.
Containment as a standard practice has seen greater adoption over the past four years than ever before. The increase in adoption is due to a very common goal of all operators of any data center, to achieve the ultimate efficiency while minimizing cost and effort.
There has been and will continue to be many different forms of data center containment. Some of the most common are:
Hot Aisle Containment - which is the practice of containing all the hot exhaust air from IT equipment into a single aisle and containing it with products such as aisle containment doors, vertical cabinet panels, and other such products. These products work well in either a raised floor environment to deliver cool air up through perforated floor tiles typically position in the front of a cabinet. Or in what is known as a slab environment where the floor of the data center is just a slab of concrete. The challenge with Hot Aisle Containment (HAC) typically comes in the form of cable management. If your data center uses overhead ladder racks and trays to run networking cables, you have to find or engineer products with brush cutouts in the panels that allow the cable trays to enter and exit the aisles. Due to the openings in the panels, this is a potential point of the application that can result in lower than optimal containment conditions when compared to other applications. A recent trend in new data center builds been to incorporate HAC from the onset of the project. By planning HAC into the building plans of the data center allows the data center managers to coordinate cabling, cooling, and other infrastructure obstacles. More on this topic soon.
Another typical containment application is the exact opposite of HAC which is Cold Aisle Containment (CAC). Cold Aisle Containment has much fewer moving parts within the application when compared to HAC. A typical CAC application can consist of aisle containment doors and a roof panel that either retracts or drops out for fire safety reasons. Like HAC, CAC can also perform well in both slabs or raised floor environments. CAC is a preferred method for data centers that is retrofitting containment due to its fewer products. CAC does have its share of points of failure. One such point is the need for egress in aisle containment doors. Due to possible pressure build up from the enclosed aisle, containment doors should have some room to allow the pressure to escape. Which ultimately allows cold air to escape and hot air to mix in from the outside.
In both HAC and CAC application, every data center needs to be inspected by a local fire marshal. Since the purpose of containment is to contain an area that needs to be serviced by IT managers and is a harsh environment, the fire suppression system needs to be able to access these areas at a critical time. HAC has a higher probability of allowing access to the fire suppression system without any significant modifications of the standard panels that make up the HAC application. CAC is a much more challenging application to adhere to local fire code. CAC typical application calls for a roof like structure on the aisle itself. Standard fire suppression systems are located at a higher point in the building to allow for maximum coverage in case of a fire. Containment manufacturers have gone to great lengths to innovate to meet this challenge. There are Drop Away Roof Panels that have a special insert in the panel that is engineered to melt out of its frame at 165 degrees to allow for fire suppression to reach inside the aisle in the event of a fire. Other products are directly tied to the fire suppression system themselves as to very quickly retract when the fire system is activated. Some roof panels have a small cut out in them to lower the actual fire suppression sprinkler heads into the aisle with rubber gasket seal to try to keep optimal containment.
Both HAC and CAC have advantages and disadvantages. Implementing cabinet level Containment addresses and overcome many of the challenges associated with both approaches and the modularity of the system makes it easier to scale and maintain.