| 摘要 |
PURPOSE:To effectively prevent wetting of the wall of a hot water heater caused by moisture condensation and generation of fume or the like even when a thermal efficiency is made extremely high by a method wherein a passage for mixing a hot gas with the discharged gas from the heat exchange unit for hot water heater is provided. CONSTITUTION:In order to supply a hot gas to a discharged gas from the heat exchange unit A for hot water heater, a passage 12 having its starting end connected to an air feeding passage 5 for supplying preheated combustion air to the burner 2. Thereby, the heat exchange unit A is constrructed such that a temperature of the discharged gas from the heat exchange part A is kept at a sufficient low value so as to obtain a sufficient high thermal efficiency, such problems as a wetting at the lower portion of the inner case 1 caused by the condensation of moisture in the discharged gas under cooling by the surrounding atmosphere or generation of fume can be eliminated and at the same time a volume of air in the air supply passage 5 can be increased and a damage by burning of the inner case 1 can effectively be inhibited. |
