Counter Current dryers are more suitable for materials that must be dried to very low levels of moisture, where the last traces of moisture are difficult to remove, or where an elevated product temperature is desirable. They are also used effectively as combined dryer/preheaters.However, since the final product is in contact with the gas at its highest temperature the counter-current dryer is often unsuitable for heat sensitive materials. Although this system can be more efficient, moisture which is to remain in the product, is not so readily controlled.