A discussion of modular data centers can be quite broad or relatively limited. This variation depends on what a “module” is seen to consist of, and that can vary widely. The module in a modular data center can be the entire facility or an individual component. The broad view of modular data centers includes all of the following:

• Containerized systems

• Modular data halls

• Modular data center buildings

• Modular systems in traditional buildings

• Modular MEP components

These are generic categories which in some cases include products from different suppliers that show significant variations from each other. In some cases, providers have branded their products using intentionally different descriptors. But as broad categories, these capture the marketplace options.

The benefit of any modular solution comes from standardization to control cost and speed delivery. Because all data centers are complex, highly technical facilities, any standardization necessarily involves a myriad of large and small decisions, which affect reliability, resiliency, and maintainability, and all of which are then fixed or fixed with options. The more a solution is standardized, the more it inherently becomes a solution looking for a problem to solve. All of the providers of modular data center solutions do their best to anticipate the needs in the market place. By designing their products to meet those needs and including some flexibility to vary their product, they meet a broader range of needs. However, they must be careful since flexibility may tend to reduce the benefits of standardization.

In the event that an owner’s need is a close fit to a standardized solution offered, then that modular data center solution may offer significant value. If the fit is not so close, then compromises must be made. For each type of modular solution, the equation is different. Modular solutions are generally marketed as universal solutions that are “better, faster, and cheaper” than traditional construction, however, some restrictions may apply.

Containerized modules are offered by numerous providers and have their origins in actual shipping containers modified to serve as dense, individual, mini-data halls. They are intended to arrive on-site loaded with IT and offer the potential of nearly instantaneous capacity. Some solutions include complete integrated power and cooling solutions and need only a secure landing spot to become immediately operational. Other solutions require cooling capacity and critical power to be provided from an external source. The uniform characteristic is that the IT component is packed in as densely as possible.

These systems have found some traction in the marketplace, primarily for users who have compute needs in remote locations where infrastructure is not available, costly, or impossible to construct. It also applies for users who have a continuous need for additional capacity of standardized IT equipment and flexibility regarding where that capacity is placed in service.

Most systems are not intended to facilitate replacement of individual IT components, necessitating a refresh strategy of pulling and replacing the entire container preemptive to significant loss of capacity or in response to progressive IT failure. This may align better to the deployment of large arrays of matched technology than to a mixed bag of processing and storage equipment. If critical power and cooling must be installed to support containerized modules, then the lead time for that infrastructure may negate the advantage of any facilitated delivery of the modules.

For the right situation, containerized modules may offer a good solution, but they have not found a large place in meeting the general capacity requirements of the marketplace.

Modular data halls are available in models designed for installation inside a shell building, which provides the primary weather protection and models designed for exterior installation. Available in different sizes and capacities, they include internal data hall cooling components and electrical distribution. They require connection to external chilled water and critical power sources.

Although they are similar in function to containerized modules, modular data halls are designed to house traditional computer racks and are similar to purpose built data halls in terms of access and configuration. They anticipate racking, connection, and refresh of IT components in the same ways that they would occur in a traditional facility. Because modular data halls represent relatively compact units with integrated air handling components, they are designed for specific capacities in terms of numbers of racks, as well as electrical distribution and cooling in kW per rack.

Modular data halls find a place in the market between containerized modules and complete modular data centers for owners who wish to customize their infrastructure solution and standardize their data hall solution. This has not yet represented a large segment of the market.

Modular data center buildings from several vendors offer complete free standing solutions with various degrees of flexibility in choosing optional capacities and components. These data centers are constructed using standardized manufactured components and assembled to provide a turn-key solution to owners. Like traditional purpose-built data centers, they offer substantial, open data halls that allow flexible IT solutions. The solutions from various providers vary regarding the number and types of standard options they offer and the flexibility they provide in mixing and matching components. Along with the containerized and modular data hall solutions, production capacity must be matched to market place demand, and delivery times may be extended if that match is not achieved.

These fully formed modular data center buildings represent the largest commitment to a standard product of all the options discussed, and may require the most significant commitment to the overall topology and the detailed execution of both the design and construction of the critical infrastructure components. In an industry that is notoriously “hands on” during both the design and construction phases, this may be a lot for an owner to give up, particularly if project turnover is the first time they have access to their facility. Time will tell us if the multiple products available in the marketplace will gain any significant market share.

Modular systems in existing buildings have been common for quite a while, and are a response to some of the same influences that have produced other modular solutions. These systems approach the problem of just-in-time delivery of capacity in a different way, and in some cases require initial investment in shell building and perhaps “back bone” infrastructure. The modular aspect is associated with equipment and systems that are available in an immediate time frame and which add an additional block of capacity. This support can be through an additional block of data hall area or adding further capacity to a centralized system. The “module” is generally viewed as a block of capacity, and making it available involves analysis of the most critical component on the critical path of construction.

Often the time frame to put such a block into service can be measured in a few weeks or months. Because such systems are often physically proximate to, integrated with, and controlled by existing systems, there may be challenges in terms of commissioning and risks associated with construction. Careful design and anticipation of the sequencing of these projects is critical to reducing such risks. Alternately, such modules can be nearly completely independent and may involve only cross connections related to redundancy.

Modular systems in existing buildings tend to be used to conserve and control capital expenditures within traditional construction programs. This can be effective in doing so within the constraints of a fully customized MEP design. Critical evaluation of the design and delivery schedule, along with expedited delivery of some standard components, can reduce shell building construction times to be competitive with other modular shell building solutions.

Modular MEP components represent another modular alternative that has been developing over time. Some equipment has been delivered in this manner for years — think generators in exterior enclosures, IDEC units, and air cooled chillers. Skid mounted mechanical components such as pumps and small chillers have been used for years in industrial applications, but have not found a strong place in data centers. Skid mounted UPS and electrical switchgear lineups for interior installation have found some traction, and recently exterior enclosures for skid mounted UPS has found more applications. These components are generally incorporated into an otherwise more traditional construction project.

The promise of these applications is also “better, faster, and cheaper,” with some success in situations with well-matched needs, just as with other solutions described above. The “faster” criterion certainly applies to installation, which can go very quickly, but can also relate to delivery, when a total volume commitment can be made reliably to a manufacturer. As mentioned, this is where modular delivery may be most dramatically effective. An ideal situation is one where an owner can have confidence in the overall need for modular components in advance of knowing exactly where the components will be utilized. It takes a well-coordinated building program to allow this confidence. One where the traditional construction projects are crisply funded, designed, and constructed on a predictable schedule. Using this approach, it is possible for traditional purpose built projects to achieve schedules which are competitive with modular data center buildings. Significant cost savings accrue with the dramatically shortened construction schedules.

The additional benefit of flexibility is available in this modular option because the “module” can be a custom product designed specifically to support the topology and capacity requirements of the building that they support. In order to achieve the delivery and cost benefits of standardization, it is critical to stay with the selected design; however the design is initially flexible.

CONCLUSION

It is the trade-off between standardization and flexibility that is the key to success with any modular solution. The natural tension between the two is resolved differently for each of the categories of modular solutions and further differences lie in each specific manufacturer’s solutions. For the less flexible solutions there is the possibility of more compromises to be made, but only where there is a miss-match between the capabilities of the modular solution and the needs of the owner.

When evaluating the “better, faster, cheaper” claims it is generally possible to measure and evaluate, on a mathematical basis, the faster and cheaper aspects. Claims of “better” can be more subtle and difficult to put into perspective. A thorough and critical evaluation of the owner’s needs, compared to the strengths and drawbacks of each solution, is required to make this determination.