The present invention utilizes hot air containing water discharged from a heating space to pass through a top/down bended fluid pipeline (1035) formed by an external part of housing (1030) of a pipeline segment having watercondensing function (1029) and a top/down bended flow guiding structure (1032), meanwhile external inlet air halving relatively low temperature passing through an internal part of housing (1031) of the pipeline segment having water condensing function (1029) is pumped in to enable the hot air containing water to be cooled, thereby the contained water is condensed and thereby is collected or flows with a part of the hot air to pass through an hot air shunt port (1026) for being guided to be discharged from an external discharging port (109); and a part of the hot air is guided by the hot air shunt port (1026) to flow towards a returned hot air inlet (1022), thereby reducing the thermal energy loss and saving electric energy.
