Pneumatic Products introduced the concept of pressure-swing desiccant drying technology to industry back in the 1940's. Heat-Les™ desiccant dryers are the most common design in use today to deliver stable pressure dew points to -100°F. Desiccant bed regeneration is accomplished using a side-stream percentage of clean, dry, internally supplied compressed air. This allows them to excel in areas where the ambient air may be compromised.