Method and apparatus for avoiding frost or ice build-up on exhaust vents and air intakes of condensing appliances

(canceled)

(canceled)

A method of avoiding frost buildup on frost condensing surfaces at or near an air intake opening of a condensing appliance, the condensing appliance having an exhaust vent that transports a stream of exhaust gas from the condensing appliance to the outside atmosphere of the building and an air intake pipe that transports a stream of combustion air from the outside atmosphere of the building through the air intake opening to the condensing appliance, the method comprising:

• a) disposing a heat-conducting path between the exhaust gas and the frost condensing surfaces, said heat-conducting path having a first section comprising a finned first heat exchanger in thermal contact with the exhaust gas and a second section comprising a second finned heat exchanger in thermal contact with the condensing surfaces;
• and
• b) transferring heat energy from the exhaust gas to the frost condensing surfaces along the heat-conducting path such that the condensing surfaces are heated by the heat energy, thereby avoiding frost buildup at or near the air intake opening.

(canceled)

(canceled)

25-30. (canceled)