Air Separation Systems in Data Centers: The Good, the Bad and the Ugly
What is an air separation system and why do they exist in a data center?
Data Center air separation solutions are meant to create separate milieus within an overall space and are intended to keep cool air confined to the locations that need it most. These include physical barriers installed in data centers that generally consist of plastic curtains, plexiglass panels, or even cages.
Far and away the biggest reason data centers install physical air separation barriers is to regulate temperature within critical spaces. Keeping the cool air generated by HVAC systems as close to server cabinets as possible is the key to achieving efficiency within the environment. However, traditional ductwork has limitations in terms of how precise it can disperse air and, as a result, physical air separation systems exist to compensate.
There are secondary reasons to install barriers in data centers, though these are less common than air separation cases. One reason may be to keep certain areas free of dust, dirt, and other debris that might get tracked into the facility by people. Another is enhanced security or restricting personnel access within certain spaces. Again, however, these use cases are generally less common than air separation to achieve better temperature consistency and are often more a secondary benefit than a reason for adding barriers.
Are air separation systems a good idea?
If you understand that air separation barriers are intended to compensate for the limitations of a data center’s HVAC solution, then the most obvious course of action is to create a system that is more efficient and eliminates the need for physical barriers in the first place. Designing a data center HVAC system that delivers air precisely where it is needed, and with the correct volume and velocity, will ensure the air separates naturally in a way that keeps cool air close to the servers and hot air moving up and out of the room without the need for physical barriers.
In some cases, particularly when retrofitting existing spaces or when using traditional metal ductwork is unavoidable, air separation systems may become a necessity. In these situations, it is important to understand how a physical air separation barrier system will impact the data center so these effects may be reduced to the extent possible.
The most obvious impact of installing an air separation system is the effect it has on costs. Ductwork and other HVAC system components will still be part of the budget, but now engineers and general contractors will need to also account for the sizeable cost of materials and installation for the air separation systems themselves.
Some contractors attempt to save money by installing simple plastic curtains (like those used in the food processing industry) rather than opting for plexiglass walls, but these are less performant and do not last as long, requiring maintenance and replacement over the long-term.
Designing a system that accounts for air separation barriers is not as simple as accounting for the barriers themselves. There is a cascading set of effects for which contractors and engineers will need to account. For example, how does a separation system impact the facility’s needs in terms of fire code? Will additional sprinklers need to be installed in the newly created spaces?
Planning an air separation system can also create headaches due to the valuable space large containment systems take up. Will the space be able to accommodate fewer server cabinets as a result?
For those designing and building data centers, the decision to install air separation barriers will need to account for all down-the-line implications.
As do all components of a data center, air separation systems require installation time. In some cases, the time required to install the barriers separating individual spaces is significant and can impact project timelines.
Unless mini barriers are installed around each individual server cabinet, one can assume there is still inefficiency and waste in a system that needs to use air separation barriers. As a result, there is a give-and-take relationship between server performance and utility-related costs. No matter which you prioritize, there will be less-than-optimal results somewhere.
When it comes to accounting for all the potential costs and implications of installing air separation barriers in a data center, the best course of action may be to avoid opening that particular can of worms entirely. By designing an HVAC system with precise air dispersion, cooled air can be delivered directly to the server cabinet and can be done in a way that reduces mixing or cool air escaping into the surrounding environment.