Appliance Design - June 2008 - (Page 37)

FaNS & BlowErS ed in the technology for residential applications, particularly evaporator fans and condensers on the refrigeration side. Studies by John Belko, senior product design engineer for A.O. Smith, whose findings were reported in “International Appliance Manufacturing 2008” (p. 30), found substantial energy and noise savings at similar outputs in both bench and in-unit testing of a refrigeration evaporator fan. Traditionally, an evaporator fan uses an ordinary axial fan, which tends to throw the air outward and often requires a shroud to redirect airflow. Belko found that with the PAX fan — and its centripetal capabilities — the airflow was better directed and eliminated much of the turbulence that could cause drag and vibration and ultimately reduce efficiency and create noise. In addition, Belko found he needed less input power to achieve the same output capacity. Bench testing of a 100-mm fan in a wind tunnel at 0.02 in. – 0.03 in. H2O of static pressure, Belko found similar airflow levels were achieved compared to the baseline fan and there was a reduction in the energy required to power the motor and fan. (See Fig. 3). The tests showed that airflow was 57 cfm for the baseline, while the PAX unit was 55.8 cfm. Power use dropped from 5.56 W to 4.29 W, and noise was reduced in terms of sound power (41.4 dba to 39.5 dba) and sones (0.43 to 0.33 sone). (See Fig. 4.) Belko also conducted a 3-day, in-unit test, which showed daily energy consumption dropping from 1.028 to 0.988 kWh per day. The in-unit testing of a 110-mm fan also found reductions in power requirements with similar outputs. Delphi’s studies found similar benefits. The company has developed products for both the HVAC/R and consumer electronics industries and debuted them at the 2007 AHR Expo and the 2008 Consumer Electronics Show, respectively. Delphi designed direct current (DC) axial fans for the consumer electronics industry and metal axial fans for the residential and light commercial HVAC/R market. In addition, the company says it can custom design a fan to fit a particular application. While energy and noise savings, as well as improved airflow output, depends on the specific application, Delphi’s studies of fans used in data server applications achieved a 15 to 20 percent reduction in power consumption and a reduction in noise of 2 decibels or greater, says Mark Parisi, product line manager, Air Management Systems - Delphi Thermal Systems. Other studies performed both by Delphi and some HVAC OEMs found that the blade technology increased efficiency by 30 percent to 35 percent as compared to other fans in the marketplace, and increased airflow volume by 12 to 15 percent without having to increase power to the fan motor. These and other results look promising to all of the principals involved, and they feel that this is just the beginning. New products including centrifugal blowers are currently being researched. Other new applications may occur anywhere air needs to be moved or something needs to be fancooled, all of which can benefit from fan designs that improve air flow. Nature may have had 3.8 billion years to design its processes, but manmade designers are starting to catch up. < For more information, enter . . . . . . . . . . . . . . . . . . . . . . . . . . 300 Or email: shekar@paxitllc .com Thinner is Better Problem: Provide overcharge and short-circuit protection in the tight conﬁnes of today’s rechargeable battery packs. Solution: 1 Involve a Pepi® sales engineer 2 Choose the right control 3 Customize to meet application needs The Pepi® Model V is only 0.061” thick, but provides maximum protection and minimal power drain due to low internal resistance. We have many reliable solutions that ﬁt in small spaces. To ﬁnd the one that’s right for you, call or visit our web site. www.pepiusa.com Only Pepi® thermostats and thermal protectors offer so many options in ﬁt, conﬁguration, cost and customization. For a close look, send for our new Disc-Type and Conductive-Type Catalogs today. www.pepiusa.com Portage Electric Products, Inc. N. Canton, OH U.S.A. salesinfo@pepiusa.com • 1-888-GO4-PEPI For more Information Enter 112 www.applianceDESIGN.com AD06084Port.indd 1 applianceDESIGN June 2008 37 5/15/08 9:59:12 AM http://www.pepiusa.com http://www.pepiusa.com http://www.pepiusa.com http://www.appliancedesign.com

Table of Contents Feed for the Digital Edition of Appliance Design - June 2008

Appliance Design - June 2008 Contents Editorial Shipments/Forecasts News Watch 21st Annual Excellence in Design Winning Designs Combine State-of-the-art Technology with . . . Meet the Judges Design Marts Fans & Blowers Mother Nature Has Her Own Ideas About Designing for Fluid Flow . . . Using CFD Simulation Software Early in the Product Development . . . Electronics Digital Signal Controllers Enable Digital Motor Control . . . Classifieds Meetings Advertiser’s Index Association Report: AHRI

Appliance Design - June 2008

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