July is usually the hottest month of the year in Connecticut, so this is a good time to consider how data centers cope with elevated temperatures.
Heat is a byproduct of the power provided to servers and other IT systems at a data center. Effective heat management is essential because excessive heat can damage these systems and disrupt operations.
For example, record heat in Europe (104 degrees F) recently forced the temporary closure of data centers in the UK. Both the London based Google and Oracle data centers were powered down to prevent significant damage to servers and other equipment that could have caused prolonged outages.
There are many things that can be done to manage heat in a data center. Here is a list of some of the most important things you can do.
- Provide Enough Cooling Capacity for Your Data Center
- Maintain Air Conditioning Systems
- Design Your Data Center to Optimize Cooling
- Disperse High Heat Generating Cabinets
- Continuously Monitor Heat at Critical Locations Throughout the Data Center
- Respond Immediately to Heat Alerts
- Deploy Additional Localized Cooling To Address Heat Spikes
Let’s consider each of these recommended steps in detail.
First, the data center must have adequate cooling capacity in its air conditioning systems to handle the maximum power consumption and resulting heat generation that can be anticipated. Provisioning more cooling capacity than will ever be needed provides a safety factor and is good practice.
Having adequate cooling capacity is not enough. Maintaining CRAC units, condensers, and other air handling systems is an ongoing requirement to make sure these vital heat management systems function properly.
The floor layout of the data center also can be used to manage heat. Rows of cabinets are positioned so the rear sides of alternating rows face each other. By setting up a Hot Aisle/Cool Aisle configuration, cooled air coming from the Computer Room Air Conditioning (CRAC) systems is passed first to the front of the server cabinets. Heat is transferred to the cooled air from the powered equipment in each cabinet. Warmed air is then returned to the CRAC systems after exiting from the back of the cabinets so that it can be cooled once again and sent back to continue the process. The Hot Aisle/Cool Aisle design is proven to be more efficient than a layout where both cool air and hot air are intermixed in a single aisle.
Dispersion of higher heat generating cabinets is another way to minimize the impact of high temperatures in a data center. The amount of heat output by the systems in a cabinet can be highly variable. Some processor intensive servers consume a lot of power and thus generate a lot of heat. Other equipment may be much cooler. When possible, dispersing higher heat cabinets throughout the data center can minimize concentrations of heat.
Continuous temperature monitoring throughout the data center is essential. Colocation data centers establish a target temperature range where servers operate safely but where energy is not wasted. The cooler the temperature, the more energy is required. The key is to set a temperature target that is cool enough to protect IT systems but not so cool that energy costs are excessive. When monitoring systems determine a temperature is above the established threshold an alert message is issued. Data center personnel receive alerts immediately at any time of the day or night.
When an alert is issued data center professionals respond as quickly as possible to determine the cause of the elevated temperature. Once the cause is identified they work to rectify problems so that equipment is returned to a safe operating temperature.
Sometimes specialized local cooling systems are employed to address a temperature spike. Data Center engineers can quickly set up these systems to focus additional cooling to a cabinet or cabinets where elevated temperatures have been reported. This prevents a serious problem while the source of the higher temperature is determined.
Managing heat in a data center is an essential ongoing responsibility. Proper air conditioning systems coupled with an experienced staff ensure operations without disruptions. CAPS’ team is proud it has successfully managed the heat of over 20 Connecticut summers without experiencing a single unscheduled data center outage.
