I recently completed a data center project at a large hosting facility. In case you’ve never seen one (they’re generally behind fences in buildings with no windows), data centers house most of the web servers that we all rely on when we surf the internet. Given that users demand that the internet be available 24 x 7 (“high uptime”), these data centers need to operate consistently and correctly at all times.
To accomplish this, data centers have multiple redundant systems so that if one component fails, there’s a “spare” ready to pick up the load. These redundant systems include web servers, data switches, fiber-optic connections, electrical switchgear, multiple power company service lines, on-site back-up generation, and mechanical cooling systems. The computers generate a significant amount of heat so if the cooling goes offline, the servers can’t operate for very long.
As you can imagine, to operate this type of facility requires complex, integrated controls to monitor system performance and provide operators the tools to automatically respond to a variety of possible situations. The systems are designed to respond to multiple simultaneous failures. However, design is one thing and operation another.
To make sure that the systems operate as planned, a series of tests are performed to make sure that the huge investment in redundancy actually delivers results when needed. This process is called commissioning, and it’s quite similar to the commissioning that all building systems should be put through before going into operation. For data centers, this process is carefully choreographed as it involves a variety of trades and vendors. Individual systems are tested twice, and then the whole system is tested once again. Therefore, data center owners (and their clients) can be relatively assured that systems will work as planned.
Unlike some controls guys, I appreciate a rigorous commissioning process. We’re all human, and components don’t always work correctly so I believe that a careful review by another set of eyes helps me to deliver the highest quality to my clients. A well run commissioning doesn’t have to be confrontational as long as everyone remembers that the goal is to help everyone to do their best.
For most commercial buildings, the commissioning process is much less intensive, and for the renovated existing buildings, commissioning (“retro-commissioning”) may not occur at all. In my opinion, this is a big mistake. Even though a commercial building may not have the intensive high-uptime demands of a data center, it’s still connected to the power meter. Any parts of the system that don’t operate correctly generally result in wasted energy and money. Over the life of a building, these cost can be large.
Owners should remember that all systems tend to drift as they age, and buildings are often re-purposed over their lifetimes. Therefore, I highly recommend that clients include commissioning for all new buildings and periodic retro-commissioning for all existing buildings. It may seem expensive upfront, but it’s well worth the expense.