摘要 |
1. A condensing boiler for heating with a heat-bearing fluid comprising an inverted burner (1) in the upper part of the boiler above a heat exchanger (2) provided with at least one tube (17) in which the heat bearing fluid circulates, whereas a collector (3) for the condensates and combustion gases is provided under said heat exchanger (2), said boiler being characterised in that the tube or tubes (17) of the heat exchanger (2) are disposed in communicating stages such that each stage exhibits a fluid circulation path of a length which decreases from one stage to the next from the top downwards, the inlet (21) for fluid to be heated being connected to the lowest stage and the outlet (22) for heated fluid being connected to the highest stage. |