Intelligent Controls Improve Energy Efficiency by Enabling Cooling Units to Work Together
Uncoordinated controls can cause a site to consume more energy than necessary as exemplified when the cooling systems in a data center environment are not working together. Unit fighting wastes a lot of energy.
In many data centers, cooling units in different locations often work at cross-purposes. For example, a unit in one area of the data center may be adding humidity to the room, while a different unit in another location is trying to extract humidity from the space at the same time. Both operations could be consuming energy that they don’t need.
This unit fighting is expensive as seen in the following example in which the energy cost is assumed to be 10 cents per kilowatt hour (kW/h) for a customer using intelligent controls on 32 cooling units operating in a single zone. When unit fighting accounted for five percent of operating time (438 hours), the customer was wasting $1,734/unit each year. When unit fighting accounted for 30 percent of operating time (2,628 hours), those figures escalated to $10,406/unit in wasted energy.
Using smart controls to keep the peace and save the budget
With both energy consumption and costs on the rise, energy efficiency has become a top concern for most data center managers. One way managers can improve efficiency is by eliminating unit fighting through intelligent controls that enable cooling units to work together as a team.
Integrating intelligent control capabilities into data center cooling brings high-level supervision, communication, and monitoring to multiple cooling units. This allows the units to work as a single system to optimize room environments and drive data center infrastructure performance.
Depending on data center specifications and existing equipment, a unified cooling environment can improve efficiency by 28-40 percent. Since each percentage point in efficiency improvement translates into $6,000 in annual savings in operating expenses (based on a 600 kW load), investing in controls that create harmony in the data center is well worth the effort and cost.
How intelligent controls work
Intelligent control works by connecting cooling units together to operate in zones. This allows them to coordinate the fan speed and cooling as needed to optimize performance. Shifting more of the workload to different units or balancing the load by a single system allows the system to operate at peak efficiency while preventing units in different locations from working against each other. The control system provides visibility into conditions across the room. A master unit determines whether humidification, dehumidification, or no action is required to maintain conditions at target levels and match airflow to the load.
Additionally, intelligent cooling controls can shift operation from controlling off of return air temperature to control based on conditions at the servers. This controls the temperature and quantity of air that is actually going into the servers, which is essential to optimizing efficiency. The controls ensure the optimum combination of airflow and cooling, regardless of whether it uses compressors or chilled water. Since the temperature and quantity of the air is measured at the fronts of the servers, temperatures in the cold aisle can be raised closer to the safe operating threshold recommended by American Society of Heating, Refrigerating and Air-Conditioning Engineers (max 80.5° F; 27° C) for class A1-A4 data centers. That’s important because, a 10° F (5.6° C) increase in cold-aisle temperature can generate a 20 percent reduction in cooling system energy usage.
Getting smarter about cooling efficiency
If you’re interested in the advantages of intelligent cooling controls, contact your service provider to learn more about Liebert precision-cooling units that feature the Liebert® iCOM™ control system, or ask about a control upgrade for your existing equipment.
With the right controls, you can implement a holistic approach toward cooling system improvements that can greatly impact efficiency and the bottom line without compromising availability.