MCPc Blog

Why Modular Datacenter Design?

If you are responsible for determining the requirements for your organization's datacenter or computer room's power and cooling capacity, then you have some work in front of you. There is a lot that goes into determining your needs that is difficult to accurately predict long-term, not the least of which is how much your business will grow over the next 5-10 years. Nobody wants to purchase more capacity than they need — especially when unsure about how long additional capacity will go unused — because there is, of course, an additional cost involved with this extra space.

How difficult is it to accurately predict datacenter needs? During initial commissioning, the typical datacenter is oversized by a factor of ten and ultimately plays out to be oversized by a factor of three at the end of its lifespan (which is usually planned to be 10 years, but is more likely 5-7 years).

To further complicate matters, downtime is no longer tolerated in today's business world. Even small companies need assurance that their critical applications will be available 24/7. Since the power and cooling systems are foundational to the systems that host those applications, proper design, implementation and ongoing management are essential to achieving this expected level of availability.

Achieving fault resiliency with traditional datacenter designs  — monolithic power and cooling systems — is difficult, space consuming and expensive. Also, many older systems do not have flexible remote- or network-based management applications.

Modular Datacenters Offer an Alternative

In a word, modularity has become the proven way to overcome all of the above challenges. Indeed, we are in the midst of a transition from traditional monolithic power and cooling solutions to more adaptive and flexible modular designs.

For example, the ability to add UPS (Uninterruptable Power Supply) capacity incrementally — or in modules — as demand increases, means that it is no longer necessary to purchase an exceptionally large UPS system up front in anticipation of a potential future need.

Modular UPS systems are more flexible regarding physical location as well.

• They can be located closer to the equipment that they serve, resulting in further cost savings in wiring costs and associated labor expenses.
• Fault resiliency is more easily achieved because you can simply add redundant power modules as opposed to entire systems as in the traditional approach to datacenter design.

Power Distribution Units (PDUs) have also become modular in design, and can now be located within the computer equipment cabinets that they serve, or very close to them. Traditional design principles dictated a large UPS system positioned against a wall with one or more power distribution and circuit breaker panels bolted to the wall nearby. This resulted in vast amounts of electrical cabling running from the PDUs to the equipment racks and cabinets, which was typically run under a raised floor (which often caused another issue of the cables preventing proper airflow). As a result, modern datacenter design recommends that power and data cabling should be run overhead.

Cooling Challenges

Modular design in computer systems and storage devices has resulted in substantially greater computer power and storage capacity in a given physical space (e.g., blade servers, high-capacity storage arrays, enterprise-class network switches, etc.). A problem with this design, however, is the concentration of heat, which must be removed in order to prevent equipment damage. Consequently, older monolithic cooling solutions are no longer adequate because they were primarily designed to provide cool air but not necessarily remove heat efficiently.

This is because traditional Computer Room Air Conditioners (CRAC units) are designed to provide cooling for an entire room, and are essentially ineffective at removing the localized heat loads generated by modern computer, storage and network equipment. Again, modular design comes to the rescue by allowing air-conditioning capacity to be acquired incrementally and be physically located close to the source of the problem — the heat-generating equipment.

Benefits of Modular Cooling

People now realize the inefficiency and waste in providing cooling to an entire room when it is possible to employ modular cooling solutions that are designed to efficiently remove heat and prevent any potential intermingling of hot and cold air. This modular datacenter design offers long-term operational savings in electricity costs which can in fact be the largest ongoing expense associated with a datacenter.

Traditionally, the power and cooling in the computer room was supplied through the building's main systems. The facilities team would contact the IT department to see what their power and cooling needs were in the computer room. With the modularity of cooling units, they can be put in-line with the IT systems, removing the heat close to the source. 

Another potential benefit of modular design that is typically overlooked or unnoticed by IT personnel, but certainly appreciated by the CFO, is that equipment located physically close to the computer and network equipment it services will probably not be considered as part of the facility, and consequently it may be possible to depreciate it as if it were IT equipment. 

Modular systems are also generally more portable than traditional solutions, should the need arise — another potential cost savings.

Start with a Datacenter Assessment

To begin any datacenter design project, the key to getting started is to perform a datacenter assessment that can determine the present conditions in the room, identify any areas of concern with varying levels of priority, and ultimately offer suggestions to resolve issues and achieve greater efficiencies.

For reference, here are a few industry websites that offer further insight into power and cooling considerations for datacenters:

The Datacenter Journal

Datacenter Knowledge

 

Perry Szarka is a Solution Consultant at MCPc with expertise in data storage and network infrastructure. He works closely with clients to understand their business objectives and discover solutions to help them achieve their goals.

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