ASHRAE Journal Supplement - AMCA International In Motion - Summer 2014 - (Page 29)

systems and overestimated in process applications. So the fan capacity must be adjusted in the field. This is very easy to do with belt drives. One simply changes or adjusts the sheaves. It is not so easy with direct drive, since a change in speed at design conditions also changes the power available from the motor to handle design conditions. Still, our database reveals that 54% of the fans sold at one horsepower and above are direct drive. Below one horsepower, 83% of fans sold in 2012 were direct drive. The opportunity for increased use of fan customization and variable speed control is obvious - and will be an important part of our future as an industry. Free cooling from cool outside air will be required more often, and with more efficient controls and dampers. Capacity control of fans will become common on what were previously constant volume systems. Efficiency ratings will incorporate motors and controls packaged with the fans. Air-over and permanent magnet motors will be integrated into fan designs to boost aerodynamic efficiency. In short, this will be an exciting time of change for our industry, during which those who adapt quickly will flourish while those who remain wedded to the old ways will falter. ADJUSTING FOR REALITY Sadly, many (perhaps most) commercial and industrial fan systems are not properly matched to the loads they serve. This is true in part because the software tools used to estimate duct losses are so rudimentary, ignoring the impact of common system effects at the fan and deep within the duct system. This has created a huge retrofit market building new or modifying existing fans so that the fan's peak efficiency is more closely matched to the system as it actually exists. WHAT IS NEXT? AMCA is working with environmental advocacy groups (the ACEEE, the NRDC and others), utility advocates and DOE technical advisors to design DOE fan efficiency regulations, model code provisions and utility rebate programs that make sense, which maximize savings and manufacturer resources available, to drive efficiency improvements. These discussions will also inspire recommendations to change ASHRAE Standards 90.1 and 189.1. Most of these regulations, standards, codes and rebates will be implemented between 2015 and 2020. There will be many changes, new metrics to learn and design approaches that alter paradigms. Air systems will demand more space to reduce system effects. Ducts will be installed as designed - pipes will have to circumvent ducts, rather than the opposite, because system effects and transport losses of elbows are much more impactful to air systems than to denser fluids (water and refrigerant). W W W. A M C A . O R G www.info.hotims.com/49807-20 A M C A I N T E R N AT I O N A L inmotion Summer 2014 29 http://www.foamsupplies.com http://www.info.hotims.com/49807-20 http://WWW.AMCA.ORG

Table of Contents for the Digital Edition of ASHRAE Journal Supplement - AMCA International In Motion - Summer 2014

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ASHRAE Journal Supplement - AMCA International In Motion - Summer 2014