| 摘要 |
PURPOSE:To prevent dew condensation and freezing from occurring in the interiors of an exhaust pipe and a suction/exhaust cylinder in a space heating device which carries out heating operation by utilizing combustion gas from a burner. CONSTITUTION:In the case where a combustion rate of a burner is regulated and controlled so that an indoor temperature is maintained at a level close to a predetermined set temperature, the combustion rate of the burner is increased and regulated so as to exceed a critical combustion rate at a point of time when a given period of time DELTAT (for example, three hours) has elapsed after the combustion rate of the burner becomes lower than a predetermined critical combustion rate. Accordingly, such a condition that the combustion rate of the burner is lower than the critical combustion rate is not continued over a long period of time, and therefore such a state that an exhaust gas temperature is left at a low level over a long period of time can be avoided. As a result, dew condensation in the interiors of an exhaust pipe and the like can be prevented. |
