The data center industry has been one of the few bright spots in the US economy during the pandemic. Activity is up, resilience appears to be up, and safety measures have proven strong. Did liquid cooling systems — whose manufacturers, prior to COVID, had been touting their forthcoming ubiquity — play any measurable role in data centers having weathered this storm so superbly?
Perhaps not, according to the latest data from an Informa Engage survey, “Data Center Trends: Use of Liquid Cooling,” produced in association with Dell Technologies. It tallied the responses of 149 data center professionals between October and November 2020 and compared their responses to a similar poll conducted by Informa in 2017. About 3 respondents in 10 reported they were a line level manager, supervisor, or team lead, with 1 in 4 claiming to be a director or middle manager.
While some 30% of 2020 respondents stated they relied on supplemental cooling systems stationed close to heat sources — a gain of 12 points in three years — only 16% of respondents admitted to their facilities using liquid cooling (LC) in their production systems, a drop of 11 points over the same period. Facilities experimenting with LC, without having made a firm decision yet, rose 13 points to 19% of respondents. The remainder, amounting to nearly two-thirds of those responding, have not adopted LC systems, with 29% admitting they have no familiarity with the technology whatsoever.
You could say, it’s not good news for an industry that had always appeared to be lucrative and promising. On the other hand, it may indicate a positive trend the LC industry may not have been expecting so soon: Data centers may be running cooler today than before, even amid measurably warmer climates.
According to statistics compiled from last year’s data by the National Oceanic and Atmospheric Administration, 2020 was the second warmest year in the past 141 years of recorded history worldwide. Land temperatures for the Northern Hemisphere in particular were 3.13 degrees Fahrenheit warmer, on average, than for the previous warmest year.
In a 2020 Uptime Institute report, the firm’s executive director of research, Andy Lawrence, reported that increases in temperatures have forced facilities to add more conventional mechanical cooling apparati, such as direct expansion (DX), to their free air economizer systems. Put another way, facilities that tried to lower their cooling expenses, couldn’t. According to Lawrence, “some have been forced to hose down heat exchangers.”
In a way, you could say that’s a rather compelling adoption of liquid cooling.
The Dell survey did show evidence of facilities moving away from conventional CRAC/CRAH and toward evaporative cooling. 45% of respondents now depend on CRAC/CRAH, a drop of 9 points over 2017. Evaporative cooling use gained 6 points over the same period, to 37%.
It’s an indicator of a steady trend toward higher efficiency cooling, in keeping with data we’ve seen from Uptime and other firms. So why aren’t liquid cooling apparati picking up steam at the same pace?
One clue to the answer comes from this question: Respondents were asked to characterize the extent to which their total cooling costs (air or liquid) for all data center equipment impacted their overall operating costs. Those who ranked cooling as having a significant impact dropped 6 points over 2017 to 39%. While those rating it with only moderate impact gained 4 points to 33%. Slight impact gained 3 points to 15%, and no meaningful impact nearly doubled to 11%.
There’s a saying among those who work in IT departments: The less something costs, the lower a priority it becomes.
Here’s more evidence to support this emerging theory: When organizations that have not adopted LC were asked what has stopped them from doing so thus far, those citing “Unable to make business case for it” plummeted 25% over 2017 figures, to only 15% of that subgroup. Most of the slack was taken up by “Concerns about water in the data center,” which climbed 13 points to 39% of the subgroup.
People with budgetary responsibility for cooling systems are more familiar with LC now. Cost isn’t the issue for them anymore, but the mechanism still is.
When that same subgroup was asked which LC technology their organizations would be most likely to implement, fully half responded with the safest option from a mechanical perspective: in-row cooling, gaining 11 points. While on-chip LC (a cooling augmentation system) did gain 9 points to 15% of the subgroup, direct contact liquid cooling (DCLC, a sealed system where the fluid is circulated but still touches a plate which touches the chip apparatus being cooled) and immersion cooling (dunking bare systems in synthetic fluid) remain stuck at 9%.
Arguably, these latter two options may be the least practical, except for facilities that host supercomputers and high-performance servers, often for academia rather than industrial customers. Still, for a technology that appears to be gaining more attention, you would expect to see some market traction as a response.
Survey conducted in partnership with Dell Technologies