Difference Between Modular and Containerized Data Centers

Although they started to gain real momentum circa 2011 or so, modular and containerized data centers are still spreading their way across the industry. The two models share many similarities: ease of deployment, the ability to add more computing power more or less on demand, highly energy efficient operation, and some degree of prefabrication. Depending on the enterprise and IT needs, each has distinct advantages and disadvantages for data center design and infrastructure procurement.

Advantages of Modular and Containerized Design

Why go modular or containerized? Both models provide a standardized kit to scale out a data center piece by piece. A facility can be designed with an initial baseload for power and then built out with racks, cooling, and support equipment as needed. As more customers come on or the company grows larger, new servers and networking equipment are added to meet demand.

Because both modular and containerized data centers have some kind of standard design (which is less flexible in containers, but more on that in a moment), it is easy to tweak them until they are extremely efficient, often as low as 1.3 PUE even when they are plug-and-play container deliveries. Prefabricated components, whether they are empty racks, full preinstalled racks, or even complete systems with cooling and power included, decrease the time and effort needed to get additional infrastructure up and running.

Containerized vs. Modular

Containerized data centers—also called pods depending on the vendor/marketing term—are literally delivered in a shipping container or a structure of similar size. They are ideal for temporary deployments, like in a disaster area. They can also be a convenient way to add additional servers for companies whose data centers are overflowing, if they aren’t ready to move to the cloud. Containers can be modular but the opposite is not always true.

Containerized data centers may come with cooling and power preinstalled. These two components are the most likely to be left out, while everything else is usually included. A container that has external cooling and power components appears quite similar to modular designs, but often times container vendors strongly prefer or even require the use of specific hardware vendors, locking companies in to a single ecosystem. While more pods can always be added, they lack the advantage of modularity in that a single point of failure can take down a whole pod. The water and cooling systems remain distinct, so that pod can’t share the cooling capacity of neighboring pods. Many pod configurations, therefore, are not concurrently maintainable. They are also small and cramped to work in, another reason they’re better suited for temporary deployments instead of a permanent addition.

Modular data centers offer many of the same advantages, with varying degrees of prefabrication, but with concurrent maintainability intact and support for wider varieties of hardware. A modular design at its simplest is an empty hot/cold aisle of racks with external cooling and power systems and a network connection. Depending on the implementation, different components can be easily added with packaged components, including full racks. Prefabricated power systems can be added when power capacity is exceeded. These often include UPS, transformers, rectifiers, switchboards, and transfer switches. Cooling systems can also be prefabricated, including some combination of pumps, chillers, plumbing, condensers, and air handlers.

Some modular designs look much like containerized designs and can simply be linked together to form a long data hall as they expand. Other modular designs are basically traditional data center designs that are built out progressively. For example, the new Green House Data facility will start with 5 MW capacity powering a single data hall, cooled by three air handlers. As we expand we’ll add more racks, cooling, and power systems until we hit the maximum 8 MW possible in the building. Our racks are placed in pods within the data hall for hot/cold aisle separation as well as this progressive building method.

Posted By: Joe Kozlowicz