Abstract: A flue gas heat recovery device is described. The device includes a packing tower. The packing tower is adapted to receive a flue gas stream. The packing tower also contains at least one water inlet, a water collection reservoir and a packing tray positioned between the inlet and reservoir. An air induction assembly may be attached to the packing tower or the inlet. A fuel gas line is in thermal communication with the reservoir. The fuel gas line has two ends a first end in close spatial relationship to a distal end of said reservoir, and a second end in close spatial relationship to a fuel output. Finally, a fluid conduit connects the second end of the fuel gas line and the water inlet.