TS Series offers choice of either constant speed drive models TS-20, TS-32 and TS-32S, with capacities of 500 to 3,000 acfm, or Variable Speed Drive (VSD) models V-200TS and V-320TS, which have a capacity range of 495 to 2310 acfm. Variable Capacity Control, achieved with spiral valve technology, allows compressor to match pressure and capacity with system demand. At full load, the tandem compressor and spiral valve have proven to be 13% more energy efficient. At 60% load, 2-stage tandem compressors provide up to 30% savings over single-stage compressors.