A heater (160) is provided for use in curing tobacco or other similar processes. The heater comprises: a furnace (211) having a chamber in which to burn fuel to generate heat; and a heat exchanger (230) for transferring heat from the heater to an airflow for use in curing the tobacco or other similar process. The airflow passes outside the heater. The heat exchanger has one or more pipes (220B-2,220A-2) that connect into the chamber of the furnace and is integrated into the furnace. For example, the heat exchanger may have a plurality of pipes (220B-2,220A-2) that connect into the chamber of the furnace, wherein the plurality of pipes (220B-2,220A-2) comprises two rows of pipes, one on each side of the furnace. The heat exchanger may further include a plenum (231B, 231A), wherein each of the pipes (220B-2,220A-2) leads upwards from the furnace chamber (211) to the plenum (231B, 231A). The heat exchanger may be integrated into the furnace by the use of one or more welded junctions.