In recent weeks we’ve seen several innovative projects that use immersion cooling to deliver compute capacity in a smaller form factor, an approach that could prove useful in creating micro data centers to support the Internet of Things and other new technologies.
These designs are part of a broader rethinking of the data center and how we bring computing power to the edge of the network.
Edge computing is currently focused on streaming video, but low latency will also be important for the emergence of virtual reality and especially the universe of connected devices that comprise the IoT and edge computing.
Immersion cooling, in which servers are submerged in a liquid coolant, offers potential economic benefits by allowing data centers to operate servers without a raised floor, computer room air conditioning (CRAC) units or chillers.
Immersion has primarily been used as a cooling solution for extreme density, such as supercomputing or bitcoin mining. But several new projects showcase the ability to use immersion at the edge of the network.
The Air Force Deploys a Data Center Hut
Hill Air Force Base in Utah recently deployed a containerized data center housing servers submerged in an immersion tank from Green Revolution Cooling. The distinctive building, which resembles a hut or shed, houses 200kW of computing power in a narrow 20-foot structure.
Servers operate in an enclosure filled with a dielectric fluid similar to mineral oil. They are are inserted vertically into slots in the tank, which is filled with 250 gallons of ElectroSafe fluid, which transfers heat almost as well as water but doesn’t conduct an electric charge.
The prefabricated modular data center allowed the Air Force to quickly deploy a powerful and dense data center at a fraction of the cost of traditional data centers. Green Revolution says its Containerized CarnotJet can deliver IT capacity at approximately $2 per watt.
The container comes complete with power distribution and a hoist for lifting blade chassis, as well as sensors, controllers, and remote monitoring capabilities. Green Revolution says its CarnotJet System gives the container the ability to deliver a mechanical PUE of less than 1.05 – without any chillers or air handlers, in any environment on the planet.
The Air Force data center hut is a more powerful example of the outdoor micro data center deployed by AOL in 2011, which used air cooling with a DX (refrigerant) backup for warm days. The micro module, which housed a single rack of equipment, was tested at AOL’s Virginia campus, and operated flawlessly throughout Superstorm Sandy.
For smaller remote computing requirements, there’s the RuggedPOD, a unique immersion cooling solution that emerged from the Open Compute Project. The RuggedPOD is a compact, cube-shaped computing enclosure that is designed to live outdoors.
French engineer Jean-Marie Verdun wanted to create an extremely energy efficient micro-data center that could operate in areas with limited infrastructure for power and cooling.
The RuggedPOD features four motherboards immersed in dielectric fluid, which is similar to mineral oil. The fluid transfers heat almost as well as water but doesn’t conduct an electric charge. The system is fully sealed and runs under a vacuum, and the fluid can last 5 to 7 years.
The system is designed with a “building block” approach. Users can stack up to four RuggedPODs to expand capacity. Each unit can support 1 KW of IT load. The project leaders are planning to connect RuggedPODs to solar panels, which could reduce costs and make them self-powered for use on remote locations.
The only climate control requirement is to protect the system from direct sunlight and maintain some space between the pods for airflow. The system is fully sealed and runs under a vacuum.
Verdun, who showed off the RuggedPOD at the Open Compute Summit in March, sees many potential use cases, including edge computing and rapid expansion for data centers that run short of space or power, which is a common problem in major cities. “You can put these on the roof, or in a parking lot,” said Verdun. “In Europe, we have lots of data center providers who are looking at Rugged POD to expand.”
Cell Tower PODs
The initial focus for RuggedPOD is providing compute power for cell towers through the Open Tower initiative.
“We are building one of the most flexible and cost effective 4G LTE infrastructure to help emerging countries to bridge the gap with western countries regarding internet connectivity,” said Verdun. “In less than four days, we can set up a full 4G node. We can supply additional services like caching.”
The RuggedPOD team is exploring the potential for automating the operations of the enclosure, including the use of robotics and even drones for maintenance.
“We are working on different type of robots (drone, rail system, hoist system, etc)., the team says on its web site. “This automated datacenter has to be fully functional, no matter if it rains, snows, if it is windy, hot or cold, and with as little as possible human maintenance. We started to develop a prototype based on Lego Mindstorm and an Arduino, and are now working on a new solution with servo motors.”
Explore the evolving world of edge computing further through Data Center Frontier’s special report series and ongoing coverage.