Danfoss today announced results from extensive laboratory and field testing that demonstrate that its Peformer® VSD variable speed scroll compressors exhibit high energy efficiency throughout their speed range.
Introduced at the 2008 AHR Exposition, Peformer VSD is the world’s first high-capacity R-410A variable speed scroll offering for commercial cooling applications and heat pumps from 12 to 40 TR (tons of refrigeration) design capacity. Higher capacities can be obtained by combining an Apexx compressor with one or more fixed-speed compressors, either manifolded or in multiple circuits.
The Performer VSD solution pairs a scroll compressor with a variable frequency drive, each designed specifically for operation with the other. The uniquely designed combination enables Performer VSD compressors to operate under part load using the entire evaporator. As a consequence, the system operates at the highest possible suction pressure for the condition. Since part load conditions prevail most of the time, there are considerable savings, and the increase in energy efficiency also extends to condenser fans, pumps, and air blowers.
An Peformer VSD drive’s output ranges from 30 to 90 Hz.
“Under partial loading, at speeds below 50Hz, oil is injected to the scroll set by a patented process, eliminating leakage and preventing loss of efficiency,” said Mogens H. Rasmussen, Danfoss market manager for the VSD. “The compressor, controlled by its matching drive, exhibits high efficiency throughout the speed and capacity range.”
Rasmussen noted that end users experience considerably less operating cost with the VSD because there is no wasted capacity – unlike strategies that employ hot gas bypass or multiple fixed-speed compressors. Because capacity is varied by increasing or decreasing the scroll compressor’s speed, system noise is much less objectionable. And since the VSD capacity always matches the cooling demand, comfort inside the building is enhanced.
“For applications where high compression and significant energy reduction are required,” Rasmussen added, “the VSD scroll and drive clearly have been shown to perform better than the next best alternative.”