By implementing the remediation strategy, the hotspots were eliminated and there was a 60 percent improvement in bypass airflow, which meant the reliability of the equipment would improve. In addition, because of improvements in airflow management, the company was able to put two cooling units into inactive standby mode, reducing electrical consumption by $27,024 per year ($2,252 per month based on $0.08/kWhr). Simple payback occurred between the second and third months.
2. Seal the computer room envelope and the raised floor
Depending on what a health check of your datacenter reveals, remediation will probably involve sealing up the following areas:
* Openings in the perimeter walls, in particular, cable trays and conduits passing through the perimeter walls. Also, inspect the area around columns to make sure conditioned air is not escaping through column facades to adjacent floors. Look for other openings, including air leaks through entrance doors and elevators; loading dock doors; windows; overhead wall openings where cables pass through; and holes in the perimeter walls above the dropped ceiling.* Openings in the raised floor that do not deliver conditioned airflow directly to the face, or intakes, of IT equipment. The most common openings that require sealing are cable openings under or behind cabinets. Other openings that should be sealed are holes under Power Distribution Units or for conduit penetrations.
Case in point: In a financial impact study of a 10,000 square foot datacenter that had 400 special grommets installed to keep cold air in, simple OpEx payback occurred within the first two months and there were annual OpEx energy savings of $50,896. The capacity improvements made it possible to turn off 18 percent of computer room air conditioning units (CRAC) at an annual operating cost savings of approximately $5,000 per unit. With the recaptured cooling capacity, the datacenter managers can increase server density without incurring the capital costs of additional cooling units.
3. Improve the above-the-floor airflow management
Depending on the unique conditions of your datacenter, remediation measures may include installation of internal blanking panels; vertical end row panels; horizontal partitions over rows; cold aisle containment and hot aisle containment.
Installing blanking panels in unused rack unit openings prevent rear-to-front circulation of hot exhaust air from the servers. As equipment load densities continue to increase, hot air circulation into the cold aisle through open spaces in cabinets, as well as around the ends of rack rows and across the top of racks, becomes more significant. Installing blanking panels helps ensure the computer equipment air-intake temperature, especially at the top of racks, is below the The American Society of Heating, Refrigerating and Air-Conditioning Engineers' recommended maximum of 80.6°F.
Case in point: Two financial impact case studies, one for a high-density facility and one for a lower-density facility, were performed to demonstrate how installing the blanking panels yield cost savings by allowing datacenter managers to raise computer room temperatures to take advantage of the increased cooling unit capacities that result from higher return air temperatures. This lowers operating costs and defers capital expenditures on cooling. Further, calculations determined that simple payback can be expected in a few months.