Reusing data center heat instead of simply expelling it isn’t a new idea, but few have been able to do it effectively. The most frequently cited reason for that is that servers produce low-grade heat, meaning the heat energy is difficult to extract and move somewhere where it can be put to use.
One reason the heat is low-grade is because it usually comes in the form of hot air, and air is by far not the most effective heat-transfer medium. Replace air with a liquid medium, and the problem of low-grade heat dissipates.
That’s exactly what a company called LiquidCool Solutions is proposing. Its data center cooling technology submerges server electronics in dielectric fluid, and recent tests at a US Department of Energy laboratory have shown that not only is the technology extremely efficient at cooling servers but it can also be used effectively to heat water for typical building uses, such as handwashing.
During the tests, the system recovered 90 to 95 percent of heat energy from eight servers submerged into liquid at the National Renewable Energy Laboratory in Golden, Colorado, according to a statement issued Thursday. Using that energy, the system was able to heat NREL’s facility water from 75F to 120F, which is hot enough to be useful for the building. The researchers noted that the system may be capable of heating water even more, to 140F, all while keeping the servers within their operating temperature limits.
An important test result for data center operators was confirmation of LiquidCool’s claim that the system uses 1 to 2 percent of the amount of energy needed to power the computing equipment.
The tests are funded by a Wells Fargo Foundation program that aims to help accelerate the path to commercialization by early-stage commercial-building technologies. NREL is planning a second phase of testing for the system, which will include running operational workloads on the servers and heating water to 120F at DoE’s Energy Systems Integration Facility data center in Golden.
Ashley Grosh, who manages Wells Fargo’s program, called IN2, said LiquidCool’s technology was “disruptive.”
Read more: Is Direct Liquid Cooling Making a Comeback?
Here’s how LiquidCool’s technology works: