Recognizing and Eliminating Data Center Hot Spots

Data center operators that maintain higher temperatures within their data centers must prevent hot spots that could affect equipment performance.

Recently, Lisa Jackson, Apple vice president of environmental initiatives, discussed operating practices at the tech giant’s North Carolina data center. Where many facilities function under low temperatures, Jackson stated that temperatures in the Maiden data center exceed 100 degrees Fahrenheit.

“It’s about 103 degrees in here,” Jackson said during a recent tour of the structure.

While this may seem extreme, Apple’s rising internal data center temperatures illustrate the rising trend of maintaining higher levels to reduce energy consumption and operating expenses. Recommendations from the American Society of Heating, Refrigerating and Air Conditioning Engineers state that facilities can safely function between 64.4 and 80.6 degrees F. However, Apple has safeguards in place that allow them to utilize their computing system within a higher temperature environment, including the use of hot and cold aisle containment.

“If you have 80 degrees Fahrenheit entering the IT equipment in the cold aisle, you will have 100 to 105 degrees Fahrenheit leaving in the hot aisle,” noted Dave Kelley, Liebert Precision Cooling director of application engineering. “All of these values are functions of how much work the IT equipment is doing. If it is not at full output, then the leaving temperature could be less.”

While maintaining higher temperatures has its cost and operational benefits, data center operators utilizing this practice must ensure that they are establishing an optimal environment in which computing equipment can function. A main part of these efforts is identifying and eliminating any hot spots that may appear within the server room.

Causes Leading to Data Center Hot Spots
Hot spots can be a severely destructive force within a computing facility, and worse still, they are difficult to recognize. However, if these problem areas are not dealt with, data center operators could experience downtime or poor server performance that significantly impacts service delivery.

In order to best identify hot spots, operators should learn to look for the root causes and work to mitigate them. According to TechTarget contributor Robert Sullivan, the top source of hot spots is when there is not sufficient cold air being regulated through the cold aisle.

“This creates an effect where the cooling fans of the servers located in the bottom of the cabinet consume all the cold air, leaving the cooling fans in the servers at the top of the cabinet to suck in room air,” Data Center Huddle contributor Dan Sullivan wrote.

How to Eliminate and Prevent Hot Spots
While this airflow problem can create serious equipment issues, there are ways to address this cause. Operators can first examine the raised floor tiles within the server room to ensure that they are situated properly. Within an ideal arrangement, perforated tiles should be placed where the hot spots appear to improve airflow. During observation of the raised floor, workers should also check the wiring under the tiles to ensure that it is not blocking air circulation.

Experts also recommend utilizing blanking panels, or filter panels, to boost the efficiency of a hot-aisle, cold-aisle layout. These panels are used to cover unused rack space, thereby reducing the amount of hot air that enters the cold aisle.