| 摘要 |
PROBLEM TO BE SOLVED: To reduce noise leaked from an exhaust opening part 25a by attenuating as much as possible a combustion sound which propagates a combustion gas passage 50 formed in a flue tube 23 and flows into an exhaust space 51, in a heater 20 for combusting an air-fuel mixture in the combustion gas passage 50 which communicates to the exhaust opening part 25a.SOLUTION: An exhaust space forming part 24 is formed while protruding upward at its upper part so that a ceiling part 51t of the exhaust space 51 is located immediately below an outside air releasing part 70a, and an exhaust opening part 25a is opened at the ceiling part 51t of the exhaust space 51 in a state that a cross section of the exhaust space 51 is throttled. |
