Data centers have been around as long as the Internet, although the introduction of the iPhone in 2007 significantly increased the demand for data centers.
When the COVID pandemic required more people to work from home, the impact was to push digital demand to even higher levels. In short, as of 2023, it is a challenge to build data centers fast enough.
environmental aspects
Thousands of computer servers operating in a data center give off a lot of heat, so cooling is a critical need. A typical rack in a data center generates the heat equivalent of 30 hair dryers, and there can be 4,000 racks in a data center. In addition, the environmental aspects of cooling data centers are top of mind.
“When we talk about sustainability, it is not just about how little energy we use, but how efficiently we use water that is preferably non-drinking water,” says Jacob Jul Jensen, Head of Business Development, Data Centers, Danfoss.
sustainable cooling solutions
Data centers can’t be built fast enough to keep up with the demands of our digital age"
“How little energy can I use, how little water, and how can I source renewable energy from local sources?”
“Data centers can’t be built fast enough to keep up with the demands of our digital age,” Jensen told attendees at a press event during the AHR Expo 2023. The growth, coupled with the desire for sustainable cooling solutions, is creating opportunities for innovation, he says.
Turbocor compressors
Danfoss has expanded the capabilities of its Turbocor compressors with a higher saturated suction temperature (SST) operating range, helping OEMs bring the benefits of oil-free technology to data centers operating at higher temperatures.
Oil-free compressors do not require lubrication because the motor shaft levitates in a magnetic field. Benefits include no mechanical wear to the system and lower maintenance costs. With higher-powered servers required to deliver new capabilities such as artificial intelligence (AI), the need to cool data centers is greater than ever.
waterless, energy-saving cooling solutions
Jakob Carnemark, the founder of Endeavour Energy, a Danfoss customer that partners with global cloud companies to build data centers with waterless, energy-saving cooling solutions, shared his company’s story of using Danfoss technologies, including Turbocor compressors, as part of its comprehensive waterless cooling system.
The efficient cooling system uses no water or outside air and meets cooling needs for data centers in high-temperature climates, reducing both water and energy.
water-positive
We became an early adopter of Turbocor compressors with a long-term goal of being net-zero with zero water"
“We became an early adopter of the Turbocor compressors from Danfoss, with a long-term goal of moving from being a big power and water hog, to being net-zero with zero water, and water-positive,” says Carnemark.
“We have a broad team working through data centers putting our resources where innovation is needed.”
power usage effectiveness (PUE)
Together, current data center cooling systems optimize power usage effectiveness (PUE), water usage, energy reuse, and the capacity of data center equipment. Systems also prevent expensive downtime and keep energy consumption and carbon footprint at a minimum.
PUE, or power usage effectiveness, is a metric used to evaluate the energy efficiency of data centers.
evaluating energy efficiency
It measures the ratio of the total energy consumed by a data center to the energy consumed by its IT equipment.
A PUE of 1.0 indicates that all the energy consumed by the data center is used by the IT equipment, while a PUE of 2.0 means that for every watt of energy consumed by the IT equipment, an additional watt is consumed by the data center's cooling, lighting, and other non-IT equipment.
regular maintenance and measurement
Regularly measuring PUE can help data centers identify opportunities to improve efficiency, reduce costs
Current data centers average a PUE of 1.57, while more new builds are designed with PUEs of 1.3 or less. A high PUE indicates that the data center is not operating efficiently, and measures should be taken to reduce energy consumption. This can include upgrading cooling systems, improving airflow management, or virtualizing servers to reduce the number of physical servers needed.
Regularly measuring PUE can help data center operators monitor their energy consumption and identify opportunities to improve efficiency, reduce costs, and minimize their environmental impact.
Water management
Minimizing the water used in cooling data centers is critical. Water is an efficient medium for removing heat from a data center; however, data centers need to manage their water use carefully to minimize the environmental impact and ensure the availability of water resources.
This can include measures such as using recycled water or implementing water-conserving technologies.
Cooling towers
Cooling towers are one method used to remove heat from a data center. Water is pumped through the data center's cooling system, absorbing heat as it circulates.
The hot water is then sent to the cooling tower, where it is sprayed onto a large surface area. This allows the water to evaporate, carrying away the heat in the process. The cooled water is then sent back to the data center for another round of cooling.
Water-cooled chillers
Water is pumped through a heat exchanger, where it absorbs heat from the data center's cooling system
Water-cooled chillers in data centers use water as a heat transfer fluid to remove heat. Water is pumped through a heat exchanger, where it absorbs heat from the data center's cooling system.
The hot water is then sent to the chiller, where it is cooled using a refrigeration cycle. The cooled water is then sent back to the data center for another round of cooling.
Direct liquid cooling systems
Direct liquid cooling systems use water to directly cool the servers in the data center. Water is pumped through a system of pipes and heat exchangers that are integrated into the server racks.
The water absorbs heat from the servers, and then the hot water is sent to a heat exchanger or cooling tower to be cooled before recirculating.
impact on the water supply
Data centers can have a significant impact on the water supply of surrounding communities, depending on the size of the data center, the cooling systems used, and the availability of water resources in the area.
Data centers require large amounts of water for cooling, which can strain local water resources, especially in areas with water scarcity or drought. According to some estimates, a single large data center can consume as much water as a small town.
water conservation measures
Cooling systems that use water can also generate wastewater which can contaminate local water sources
Cooling systems that use water can also generate wastewater that may contain pollutants, such as chemicals used in the cooling process or metals from the equipment. If not properly treated, this wastewater can contaminate local water sources, such as rivers or groundwater.
Data centers can compete with other users, such as agriculture or residential users, for access to local water resources. This can lead to conflicts over water allocation and pricing. To minimize the impact of data centers on local water resources, data center operators can implement water conservation measures, such as using recycled or treated wastewater, implementing water-efficient cooling technologies, or locating data centers in areas with ample water resources.
new approach
Many data centers do not need to be as cool as one might think, certainly not as cool as a comfortable ambient temperature. For most data centers, temperatures of 24°-25°C (75°-77°F) will suffice. Newer computer designs enable chillers to generate leaving water temperatures (LWT) as high as 82° F, thus requiring less cooling cost.
As cooling systems remove heat from data centers, a new approach seeks to use that heat to warm nearby buildings tied together in a district heating configuration, a much better use of the heat than releasing it into the air.
