Abstract: This application discloses several components relating to a heating apparatus which preferably are used in conjunction with each other in an apparatus for heating solid granular or particulate material, such as aggregate used to make asphalt concrete. One component of the present invention includes a heater-condenser unit which indirectly heats the material by circulating heat transfer fluid within hollow plates contained in a housing holding the material. The material is heated, the heat transfer fluid is condensed and a condensate removal means associated with the hollow plates removes the condensate from the housing. The heat transfer fluid used in the heater-condenser preferably is supplied in the form of a vapor or gas evolved from liquid contained in material heated by another type of heater. In this other type of heater, the material to be dried enters a chamber containing hollow heat exchange plates through which a primary heat transfer fluid is circulating.