Abstract: An improved fireplace heat exchanger apparatus having one or more generally first hollow members, wherein each first member has an internally disposed second hollow member thereby creating an annular space between the interior surface of the first hollow member and the exterior surface of the second hollow member. Ducting is provided to direct air/gas flow through the heat exchanger in a controlled, counter-flow manner. The interior portion of the second hollow member is configured to accept a flow of a heat transfer medium for transferring heat energy to a desired location while the annular space is configured to accept a flow of hot combustion gasses from the combustion chamber and direct it toward a chimney. A nozzle disc located in the annular passageway proximate the inlet of hot combustion gasses causes the gasses to circulate within the annular passageway to enhance heat transfer to the second hollow member.

Abstract: Regenerator with tube system, particularly for fireplaces and the like, which can be inserted at the firebox of fireplaces and comprises a metallic heat-exchange body that is constituted by a single tubular body shaped so as to have straight and parallel portions that rest on the heart of the firebox, two identical curved loop portions that rest on the rear vertical wall of the firebox, a single transverse loop lying at the front of the firebox, and two ends that are parallel and close to each other, and are directed towards the outside of the fireplace, one of the ends being connected to a box-like body that contains a motorized fan for sending the ambient air to be heated into the heat-exchange body, the other end being connected to a duct for delivering the heated air into the surrounding space, the delivery duct being also contained in the box-like body.