Dell warranties servers for 'fresh-air cooling'
- — 28 July, 2011 22:58
Dell said Thursday it will warranty servers to run at 113 degrees Fahrenheit (40 degrees Celsius) for a limited number of hours per year, so that customers can make wider use of "fresh-air cooling" in their data centers.
The announcement comes as data centers are trying to rein in escalating energy costs. The energy used to keep IT equipment cool can account for as much as half the total cost of running a data center.
Most big data centers use chillers, big mechanical pieces of equipment that provide cold water for cooling. By contrast, fresh-air cooling is an emerging technique that draws outside air into the data center, filters it and uses that to cool the IT gear.
That can make fresh-air cooling far more energy-efficient than a chiller, but using outside air can also lead to wide fluctuations in temperature, particularly during warm summer months.
Dell will warranty many of its mainstream servers, as well as some network and storage products, to operate at 104 degrees Fahrenheit (40 degrees Celsius) for up to 900 hours per year, and at 113 degrees Fahrenheit for 90 hours per year, the company said.
That will give more data centers the opportunity to use fresh-air cooling year-round, because their equipment will be tested and warrantied for use during the hottest hours, said Eric Wilcox, power and cooling product manager for Dell.
Ninety hours doesn't sound like a long time, he acknowledged, but temperatures in most of North America, for example, rarely exceed 113 degrees Fahrenheit for more than a few hours a day during a few weeks of the year.
The higher temperature rating will allow year-round fresh-air cooling all over North America, apart from very hot and humid places like Atlanta, he said. The same will be true for much of Europe.
The announcement covers only Dell equipment, of course, and it remains to be seen if other vendors will follow suit. Some data centers divide their computer rooms into zones, so they could potentially operate different areas at different temperatures.
Dell didn't design new equipment for the higher temperatures. Its latest servers already operate reliably at 113 degrees Fahrenheit for limited periods, Wilcox said. But like most other big vendors, Dell warrantied its servers only to 95 degrees Fahrenheit. It hopes to gain a competitive edge by being the first big vendor to go beyond that limit with mainstream products.
The products covered in the announcement include two-socket 1U and 2U servers, as well as tower servers. Some systems that customers bought recently may also be covered. "Say you bought an R610 [server] six months ago, we'll warranty that under these new operating conditions," Wilcox said.
The support for higher temperatures could give data center managers the confidence to run their data centers hotter even if they aren't using fresh-air cooling, Wilcox noted. Raising the thermostat can be a simple way to cut cooling costs, but some operators resist doing so in case hot spots form that temporarily exceed their vendors' allowable limits.
Running servers at high temperatures can also shorten their lifespan and degrade performance. But Dell said the hours it is recommending will have only a "limited impact" on performance.
Dell's announcement is in line with new temperature guidelines due in September from the American Society of Heating, Refrigerating and Air Conditioning Engineers. ASHRAE has said it will raise its maximum allowable temperature to 113 degrees Fahrenheit, from 95 degrees Fahrenheit previously, also with fresh-air cooling in mind.
If customers want servers that can run hotter year-round, as opposed to short periods, vendors would almost certainly have to design new products, said Don Beaty, president of consulting firm DLB Associates and a member of ASHRAE's TC 9.9 committee, which is authoring the guidelines.
Those products may have to be less dense, and therefore physically larger, to allow for better airflow, and would cost more to purchase, he said.
But that shouldn't be necessary for data centers located where very high temperatures are an infrequent occurrence, Wilcox said.
"The idea here is to design for the 'can happen,' but not to design for continuous operation [at high temperatures] because you'd be paying a premium for that," he said.
The Dell products covered by the announcement include its PowerEdge R610, R710 and T610 servers; PowerConnect 7048R / 7048RA and 8024 / 8024F switches; PowerVault MD1xx and MD3xx storage arrays, and some EqualLogic products. Its PDUs (power distribution units) are also covered.