Cooling from the Inside Out

Small vendors look at ways to reduce the heat generated inside servers.

As demand for green data centers continues to rise, some smaller vendors are looking to build components that will reduce the amount of heat that servers generate and the amount of power they consume.

Multiple forces—from more dense servers to smaller and more powerful processors to the rising cost of energy—are conspiring to drive up power costs in corporate data centers. Smaller servers armed with more-powerful components are not only consuming more electricity but also generating more heat, which is putting pressure on the air-conditioning units in facilities.

Two small, relatively unknown companies in the Pacific Northwest—SprayCool, of Liberty Lake, Wash., and OnScreen Technologies of Portland, Ore.—have developed ways of cooling those hot-running servers from the inside out. In addition, Applied Methodologies, of Wantagh, N.Y., has developed what it touts as the first "green" server that cogenerates its own power.

An underestimated problem of high—performance blade servers is the amount of heat they generate and the ability of fans inside the systems to remove that heat. And as blade server configurations continue to grow in density, the need for cooling capabilities will increase with them.

The conventional method to cooling blade servers from the inside relies on high-speed, control logic fans, which can be inefficient and consume additional energy and power.

By contrast, OnScreen Technologies addresses this microwarming—or overheating—that is occurring inside the servers with a scientific and interdisciplinary approach. OnScreen Technologies WayCool system is a hermetically sealed liquid chamber that combines liquid and air cooling methods and uses inductive properties of carbon technology to draw heat away from the internal environment of the server.

WayCools approach is designed to lower the servers temperature and energy consumption while boosting performance in a cost-effective, efficient way. WayCools design also enables it to replace the metal panel that is inside blade servers, making it a compact, space-saving approach to cooling, according to officials. OnScreens hermetically sealed chamber is environmentally friendly and does not leak, they said.

The company is currently working with blade server manufacturers to incorporate its cooling technology into their next-generation offerings.

"In its most base form, what it does is move heat very effectively from the heat source and, in so doing, spreads it out to a much larger area, which allows it to dissipate into the air much easier," OnScreen President and CEO William Clough told eWEEK. "Rather than use the traditional method of heat spreaders—which is generally a copper plate, which spreads heat out at a very slow rate—we actually use fluid to move the heat. And so we can move the heat much, much quicker, because fluid is a much better transporter of heat than metal."

Clough said the company has done its research—OnScreen received the U.S. patent for its technology in July—and believes no one else is approaching the power and cooling of servers in this way. He said the server cooler can use anything from a fluorocarbon liquid to water with an alcohol base.

The company is talking to a "major server manufacturer" for a possible OEM deal, Clough said.

For the past eight years, power management technology company SprayCool quietly—and quite literally—has been hosing down the inside of servers for its customers. The company has gotten most of its success by selling its product to government agencies looking to reduce the heat generated by their servers.

With rising power and cooling costs now becoming a concern among corporate data centers, the company is hoping enterprises will take to spraying a fine mist onto servers.

SprayCools technology uses an inert liquid, called SprayCoolant, to cool processors in a server and remove the heat from the system without letting it escape into the data center. The coolant evaporates once it hits electronic hot spots.

The company has been trying to woo server OEMs in hopes that they will offer the SprayCool technology with their systems, while at the same time formulating a product road map that will grow the reach of the technology by expanding the types of hardware and components it can cool, said Patchen Noelke, SprayCools director of marketing.

"The strategy ... has been to [target] a commercial effort toward the data center," Noelke said.

SprayCools M-Series product line, which is aimed at data centers, offers a server rack that can hold both 1U (1.75-inch) and 2U (3.5-inch) rack-mounted systems.

Housed in the bottom of the rack is the M-Series Thermal Server, a 4U (7-inch) box that supplies the SprayCoolant to an I/O manifold in the back of the rack. The Thermal Server is connected to the data centers water loop.

Flexible plastic tubes run from the manifold to the individual processors, where SprayModule Kits replace heat sinks right above the processors and are attached via the heat-sink-mounting features. The fluid is then sprayed via Spray­Modules onto a base plate located just above the chip.

The heat from the chip causes the fluid to evaporate, and the vapor is returned to the Thermal Server, where it is recondensed in the heat exchanger.

The SprayCoolant is circulated back into the server. The system is monitored by the M-Series Systems Manager, which is linked to both the Thermal Server and the individual servers in the rack to track such data as processor temperatures. A GUI displays the data. SprayCoolant is safe for electronics, according to SprayCool officials. In some government deployments, the fluid is sprayed directly onto the components.

Applied Methodologies server, the ThermoGreen Server—announced Oct. 1—does not only comply with current energy-efficient green standards but also generates energy. An example application of this technology would be to turn a data center into a small power-generating utility. While the data center works normally, ThermoGreen servers also cogenerate energy without impacting the work the server is doing. The energy generated from a data centers servers or other ThermoGreen Server is used to offset data center power-consumption costs, a company spokesperson said.

Each ThermoGreen Server uses the energy it generates to reduce its own draw of power supplied from the local utility. In addition, a ThermoGreen server can distribute the energy generated from multiple ThermoGreen servers onto a power distribution network to scale the energy generated as a whole for other uses, the spokesperson said.

In addition, OEMs can either build ThermoGreen servers or older servers can be converted, according to the company. Applied Methodologies also is working on a host of other technologies, including a ThermoGreen Router and ThermoGreen Switch.

The cooling conditions will continue to be the same for each server because each TEG (thermoelectric generation) component within a server adds very little to the servers internal thermal budget. The use of TEGs offers a solution with no moving parts, long mean time between failure and continued operation—even if a TEG fails.

Tellurex, Watronix, Melcore, Thermal Enterprises and Hi-Z are the initial TEG manufacturers currently used in Applied Methodologies AMILabs prototype development and ongoing research of additional ThermoGreen Servers, the spokesperson said.


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Chris Preimesberger

Chris J. Preimesberger

Chris J. Preimesberger is Editor-in-Chief of eWEEK and responsible for all the publication's coverage. In his 13 years and more than 4,000 articles at eWEEK, he has distinguished himself in reporting...