The Aircel HRE/HRS-L Heated Blower Purge Desiccant Compressed Air Dryers utilize atmospheric air for regeneration of the desiccant bed significantly reducing or eliminating the use of compressed purged air for regeneration, resulting in an overall reduction in the cost of operation. No process air is used during this phase of the overall dryer cycle. Process air is only consumed during depressurization and repressurization of the off-line tower and, in the case of the HRE, during cool-down of the regenerated bed. This amounts to an average 2% of the rated capacity of the dryer. The HRS-L dryer further reduces purge air consumption by utilizing ambient air for cool-down of the regenerated bed.