The Value of Subfloor Inspections

There are several reasons for data center managers to perform a routine inspection of their subfloor plenum. Even though the subfloor plenum is often hidden from the day-to-day field of vision, it is vital to understand what may be happening under the raised floor that can cause unwanted downtime. For best results, subfloor inspections should be conducted quarterly.

Regular inspections uncover issues.

Inspecting the subfloor is similar to routinely “checking under the hood” of an automobile. It’s a good idea to review things that are generally not seen to ensure the uninterrupted operation of your car. For example, when inspecting the engine compartment, one typically inspects belts, filters, fluid levels and looks for any signs of maintenance that may be needed. Likewise, the same holds for the data center’s subfloor plenum. A regular inspection uncovers issues so they can be fixed. As a result, facility managers should routinely inspect the subfloor plenum every quarter to look for problems with access floor support structures, firewalls, raised floor panels, and air conditioning units.

Inspect access floor support structure

There are several things managers should look for when performing a subfloor inspection. First, inspect the raised floor support structure. Next, repairs and maintenance should be performed for any pedestal or stringer missing, broken, or leaning. Sometimes, an uneven floor panel can result from a more significant issue in the foundation and may need to be addressed by an engineer.

Inspect firewall integrity

Another area to keep an eye on is the firewall around the data center perimeter. Look for any holes that may be allowing air to escape or contamination to enter your plenum. In the event of a fire, penetrations in the firewall will allow smoke and fire to pass into the data center. Holes should be sealed with the proper fire-stop product. The product you select should be dictated by the size of the hole and the local fire code.

Inspect raised floor panels

In addition to holes in the perimeter walls, look for unnecessary cutouts and gaps in raised floor panels. These holes allow cool supply air to bypass servers and create inefficiency in your cooling system. Use brush floor grommets to seal small holes. Fire-rated foam may be used for larger holes. Also, look for any unnecessary airflow panels or grates. If they are not cooling a specific cabinet, then replace the airflow panel or grate with a solid raised floor panel.

Inspect air conditioning units

Another area to inspect is under CRAC units. The presence of liquids can be an indication that corrective maintenance needs to be performed. Also, look for accumulating dust and debris in that may be harmful to servers if it becomes airborne. CRAC unit drive belts have been known to create a sticky black dust when out of alignment. This can be a serious problem for servers and other sensitive equipment.

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