There are many misconceptions when it comes to the pros and cons of prefabricated data centers.  The biggest single reason for this is that when people hear “prefabricated,” they often imagine a containerized solution.  These long, narrow and relatively inflexible ISO container-based units are only one form of prefabricated facility though.  Prefabricated data centers can come in many more flexible shapes and sizes and, once built, will often be indistinguishable from a traditionally constructed brick-and-mortar facility.

Here, we take a look at some of the more common myths surrounding prefabricated data centers and discover the real story …

Design Flexibility

Myth:  Prefabricated data centers have fixed designs with space restrictions that limit the number of racks, prevent the use of an elevated floor, and restrict the types of cooling that can be employed because they use ISO containers retrofitted as data centers.

Reality:  Prefabricated data centers can be divided into two fundamental categories: those constructed with ISO containers and those that use larger modules.  Containerized facilities do indeed have many of the restrictions mentioned above.  However, module-based solutions are far more flexible and can be combined without internal walls to deliver infinitely configurable open white space.  This flexibility allows prefabricated module-based data centers to be designed with the same degree of freedom as a traditional brick-and-mortar facility but with significantly lower overall project risk and far greater utility than their containerized cousins.  They can therefore be designed and built specifically for each individual customer’s precise needs.

Lifetime Concerns

Myth:  Prefabricated solutions have limited life spans, as their steel construction will rust just as containers do that are commonly seen on trucks, ships, or trains.  So, they should only be used as temporary installations.

Reality:  Any building, regardless of what it is built of, will be affected over time by structural issues if it is not appropriately constructed right from the start.  Therefore, it’s critical to understand and prepare in advance for the environmental conditions that the data center will be exposed to.  For example, a C3 coating on a steel structure will protect it against medium corrosion risk in industrial and coastal areas, while a C5 coating will provide protection at sea or locations with extremely high levels of humidity and salinity.  So, with appropriate protection in place, there is no reason why a prefabricated data center cannot enjoy a lifetime of 40 years or more.

Thermal Considerations

Myth:  When prefabricated steel-based data centers are exposed to the sun, they can heat up inside and require an increase in cooling capacity, thus increasing PUE and the operational costs of the HVAC units.

Reality:  Internal heat gain is a potential issue for all kinds of buildings, and insulation is, of course, key.  Flexenclosure’s prefabricated modular eCenter data centers are equipped with insulated walls that deliver a very high thermal protection, with a U-Value of 0.6 W/m²K that minimizes heat gains inside the installation.  The typical U-Value for a brick wall is 2.0 W/m²K and for a glass window it is around 2.8 W/m²K, so prefabricated data centers can clearly be significantly more thermally efficient than a traditionally built facility.

Logistical Issues

Myth:  Transporting prefabricated data centers to their final locations can be logistically challenging, with special equipment and processes required that increase installation costs and time when compared to traditional construction methods.

Reality:  With the majority of a prefabricated facility’s construction undertaken in a specialist off-site factory environment, it’s actually more logistically complex to construct a traditionally built data center, because of constant deliveries of materials and heavy equipment to the site.  Off-site construction of the modules also allows site preparation to take place in parallel, thus typically reducing overall build time and project risk.  And with the individual modules specifically designed such that they can be transported by road, sea, or even by air if necessary, final deployment and commissioning of a prefabricated data center is not problematic at all.

Cost Implications

Myth:  Prefabricated modular data centers are more expensive to build than brick-and-mortar facilities due to the shipping costs, import duties, installation challenges, and specialized workforce required on-site.

Reality:  In fact, the overall CapEx investment required for a prefabricated data center project can be 10% to 20% less than an equivalent brick-and-mortar construction.  This saving can be achieved because prefabrication in an off-site clean-room factory environment allows for more efficient use of people and materials than can typically be achieved at an on-site build.  Further, the higher quality control possible in an off-site manufacturing facility and the ability to fully test most installed systems before they leave the factory significantly reduces overall project risk versus traditional construction methods and gives much greater control of overall project duration.

Return on Investment

Myth:  Prefabricated facilities do not deliver acceptable returns on investment.

Reality:  With the data services markets evolving at unprecedented speeds, data center operators are having to evolve too.  Traditional new-build projects taking two, three, or more years to plan and execute are no longer acceptable. Now, new data center facilities typically need to be up and running in less than 12 months.  They also need to deliver return on investment (ROI) in less than 18 months with an internal rate of return (IRR) of 30% or more.  Delivering on these targets with traditional construction projects is pretty much impossible, but not so with prefabricated facilities, where increased project speed and control can deliver operational facilities extremely fast while meeting all financial targets.

Project Duration

Myth:  Prefabricated data centers require a lot of installation and commissioning work to be done on-site, delaying time to operations.

Reality:  On the contrary, prefabricated data centers have the advantage of having all their systems fully installed and tested prior to the modules leaving the factory.  This not only reduces the time required on-site for final system commissioning, it also completely avoids the significant risks involved with transporting sensitive data center equipment to a dusty and busy building site for local installation.  Pre-installating systems in a prefabricated facility typically delivers a saving of up to four times the time required for equivalent on-site installing and commissioning of a data center.

Scalability Advantages

Myth:  There is no benefit to building a prefabricated data center versus a traditionally built one when it comes to the facility’s future scalability.

Reality:  Ideally, new data centers will be built according to current capacity needs while allowing for expansion as and when the business grows.  However, expanding a live brick-and-mortar data center will typically expose the facility to extreme operational risk. Therefore, traditionally built facilities tend to be specified and built according to projected future capacity requirements and this, of course, is completely inefficient.  Prefabricated data centers do not have this problem as the site works required — whether building a new data center or expanding an existing one — are relatively limited.  Prefabricated facilities can therefore be scaled up in size as and when necessary with no risk to ongoing data center operations, and, in this way, resources can be efficiently utilized with CapEx investment staged over time.

Facility Certification

Myth:  Prefabricated data centers cannot get an independent design or construction certification because they are considered to be temporary installations that do not meet acceptable availability, redundancy, or security requirements.

Reality:  Prefabricated modular data centers can be designed to meet any availability level required by the operator.  Further, prefabrication as a construction methodology has not only been fully accepted by all independent data center bodies, it is acknowledged by many as the way most data centers will be built in the future.  Flexenclosure has pioneered the deployment of Uptime Institute tier-certified prefabricated modular data centers in multiple countries around the world — with both design and construction accreditation — delivering total peace of mind to their operators.

A Prefabricated Future

It’s clear that prefabricated modular data centers can deliver everything that data center operators are looking for today.  The latest prefabrication techniques are allowing data centers to be built in a far more cost-effective way than ever before for fully flexible and bespoke facilities of all sizes, whether hyperscale, core, edge, or micro. 

It’s a process that has been tried and tested, and it works.  In fact, the main challenge faced by prefabricated data centers is not the construction methodology itself but its historical perception as a narrow and inflexible ISO containerized product.  Those times are over though.