To dispense with a louver formed as a combustion air intake on a housing, or substantially reduce the number of louvers when a regenerator comprising a combustion heating means such as a burner is mounted in the housing.

This chimney 50 is a double wall chimney mainly composed of an outer cylinder 51 opened at its both upper and lower sides, and an inner cylinder 52 opened at its both upper and lower sides and penetrating through the outer cylinder 51, comprises a combustion gas discharge passage S1 formed as a cavity portion of the inner cylinder 52, and an outside air suction passage S2 formed between the outer cylinder 51 and the inner cylinder 52, vertically penetrates through a roof portion of the housing 100, and is mounted on a high-temperature regenerator 1 of an adsorption type refrigerating machine stored in the housing 100 in a state that a lower end portion of the outside air suction passage S2 is opened in the housing 100. The chimney 50 is provided with an air discharge top 53 and a first cover member 56 for preventing intrusion of rainwater to the combustion gas discharge passage S1 and the outside air suction passage S2.