Atlas Copco Refrigerated Air Dryer (FD Series) Atlas Copco’s FD VSD mirrors your production’s demand for compressed air as it fluctuates during the day, week or year. This ensures supreme energy savings as well as a stable dew point. 1. Atlas Copco’s FD VSD mirrors your production’s demand for compressed air as it fluctuates during the day, week or year. This ensures supreme energy savings as well as a stable dew point. 2. Integrated water separator 3. High-efficiency heat exchanger 4. Electronic no-loss condensate drain 5. Elektronikon® Touch controller 6. Single electrical connection 7. Advanced remote monitoring and control 8. Robust and compact design 9. Minimal environmental impact