In yet another variation of the one-stop shop, power supply vendors are increasingly taking the first steps toward developing their own brand of standalone cooling products at the systems level. A few uninterruptible power supply (UPS) makers are taking the early lead by bringing advanced air conditioner- and chiller-type products to market under their company logo.
Unlike many standard embedded cooling-fan arrangements, these mostly active components are made to handle the heat generated by small to midsized data centers. Apart from power supplies, other new products, both active and passive, are also arriving to serve small portable needs, such as for cooling notebook PCs.
The union of power and thermal-management products appears a natural one and a sign of things to come. But it will take time. Few companies delivering power products are currently in position to establish the in-house infrastructure needed to include experts in heat and fluid flow, and so they pursue arrangements where such components as fans, heat sinks and larger systems are provided from the outside. The industry consensus, however, seems to be that a slow but steadily evolving consolidation is taking place.
With the most visible demands for cooling these days coming from data centers, vendors are pursuing basic air-conditioning approaches, as is common with large UPS installations. The newest system comes from American Power Conversion Corp. (West Kingston, R.I.). The company's PA-4000 for relatively localized cooling is a portable 4-kilowatt air conditioner with an airflow of 600 cubic feet per minute (CFM) that's designed specifically for IT equipment. It stands 3.5 feet high and has the same width as a 19-inch rack. It runs from 115-volt mains.
“As many companies grow, move departments or relocate,” said Rob Johnson, vice president of the company's Availability Enhancements Group, “the PA-4000's portability gives users the flexibility to move cooling equipment along with servers, internetworking and communications hardware.”
APC says the PA4000 provides high-efficiency air conditioning: Unlike most portable products, this one doesn't use any conditioned air to cool the condenser.
The unit is also programmable, allowing the user to supplement existing air-conditioning systems so that IT and telecom equipment does not overheat during nonbusiness hours, when the amount of cooling is usually cut back. Other features include multiple blower speed settings to address humid environments, a dual-float pump for reliable removal of condensates and replaceable industry-standard filters. The PA4000 has an estimated resale price of $3,499.
Liebert Corp. (Chicago), which was actually in the cooling business before it became involved with UPSes, launched its XD family earlier this year. It's billed as the first comprehensive solution to high-density data center cooling. The Liebert system is not an air conditioner in that it does not have a compressor. The solution consists of an airflow enhancer, the Liebert XDA, which is a fan unit that mounts to the rear of a 60-inch-or-higher rack enclosure and pulls hot air out from the cabinet; a fan coil (the XDV) that mounts on the top of the rack; and the XDO, an overhead (ceiling-mounted) fan-coil system. The latter units are supported by the company's XDP pumping unit or XDC chiller, an indoor unit that connects directly to the XDO or XDV.
“The power densities have risen to levels that exceed the capacity of traditional approaches to cooling and that is creating hot spots in the data center,” said Fred Stack, vice president of marketing. “These products enable focused, high-efficiency cooling up to 500 watts per square foot.”
Demands for cooling are beginning to extend to a variety of applications-some very surprising-at the lower power levels. One notable application is the cooling of notebook PCs. Despite some debate about the novelty vs. usefulness of such products, today's notebook PC is quite different from the product that originally debuted as a compact mobile device with limited functionality. In that context, the notebook is drifting into territory not too far removed from the bigger machines when it comes to required protection from overheating and resulting system crashes. Moreover, it's here that the notebook cooler market, dominated earlier by PC makers, is becoming more interesting to companies with highly diverse product and power portfolios.
One of the more recent arrivals is from Antec Inc. (Fremont, Calif.). Its Notebook Cooler is a fan-derived system within an aluminum plate. It has 388 ventilation holes to keep a steady distribution of airflow generated by two 70-mm ball-bearing fans. The cooler fits directly under the laptop and can be transported with it in any standard carrying case.
Antec's cooling unit is powered by the Universal Serial Bus (that is, 5 volts at 400 milliamps, no batteries or power adapter needed). Its fans, running at 2,500 rpm, provide about 32 cfm of airflow. Acoustic noise is 25.9 dB(A), well below the level, say, of rustling leaves and normal background noise, according to Scott Richards, vice president of sales and marketing. The cooler comes with a USB power cable and can be used with PCs or Macs. The unit measures 13 x 11.2 x 0.85 inches and weighs 25 ounces. It's priced at $39.95.
Future designs may provide greater cooling power. NEC Corp. (Tokyo), for instance, recently announced the development of what it says is the first water-cooling module for notebook personal computers. It uses a piezoelectric-powered pump to circulate the liquid. The hermetically sealed module is specified to provide a cooling performance of 80 W. This particular system features an ultraslim-sized pump that can operate at higher water pressure, and NEC says it will provide up to twice the traditional cooling capabilities of the conventional water-cooling system. It will work from a 5-Vdc source. The company expects the product to be commercially available within two years.
Aavid Thermalloy LLC
American Power Conversion Corp.
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