Externally Heated purge refrigerated air dryer sunwin integrating advantages of heat-exists purge and heatless purge, externally heating the purge type air,reduce it's consumption. 

It efficiently avoids the disadvantages of short switching time and consuming most of the purge air of the refrigerated air dryer sunwin and wasting electricity of refrigerated air dryer sunwin. 

The refrigerated air dryer sunwin has got rationally switch time, Little purge air consumption, also being the most economical Desiccant Dryer.