This article compares three schemes of fan control used on large air conditioning and refrigeration condensers. The first scheme is step control; the second is a hybrid with a VFD on only one bank of fans, while the rest remain step controlled. The final, and most efficient, scheme is VFD control of all fans, at all times.
In a little more than a year, 34 major corporate customers have installed, deployed or purchased more than 250 fuel cell power systems and hundreds of backup power units, totaling more than 30 MW of power. “The Business Case for Fuel Cells 2011: Energizing America’s Top Companies,” profiles this select group of companies.
Grooved mechanical piping has been changing the way contractors do business for more than 85 years, but this method of pipe joining is still unknown or misunderstood in some areas of the commercial building industry.