The dryer contains two desiccant chambers, while one chamber is drying the compressed air (adsorption), the other chamber is simultaneously undergoing regeneration (desorption). At a predetermined time both exhaust valves close and repressurization begins. Every three minutes the desiccant chambers are reversed in function, this is the changeover point. Changeover is characterized by an immediate venting of compressed air from the desiccant chamber entering regeneration. This is the "heatless regenerative" process.
For low controlled humidity in humidity chambers (below 6°C dewpoint limitation of standard humidity range) .