Abstract: A device for evacuating into the ambient air combustion products from a condensation boiler, in which at least one downstream section of the conduit for evacuating the combustion products is coaxial to the conduit for admission of the combustion air necessary for the burner. Means are provided for returning to the outside a fraction of the air collected in said admission conduit. The downstream section of the conduit for evacuating the combustion products, the coaxial section of the admission conduit and the means for returning to the outside a fraction of the collected air define a first heat exchanger. Means also are provided for diluting the combustion product with the fraction of collected air, the dilution means being located in the vicinity of the opening for suction of the combustion air and for rejection of the combustion products into the ambient air.

Abstract: A reduced wreath condensation boiler. A feed duct for fresh oxygen-carrying air taken from the atmosphere and an exhaust duct for exhausting diluted combustion products to the atmosphere downstream from the extractor fan are essentially parallel, but not coaxial, minimizing heat exchange. A first heat exchanger is disposed above the heating body for providing heat exchange between the fresh air from the feed duct and the combustion products from the heating body prior to dilution. Deflectors channel a portion of the air from said first heat exchanger to sweep the free space situated between the heating body and its airtight enclosure, while the remainder of the air from the first heat exchanger is directed towards the burner. At least one calibrated orifice injects the air which has swept over the heating body into the exhaust duct for the combustion products upstream from the extractor fan. This boiler reduces the wreath of water vapor where the flue gases are exhausted to the atmosphere.

Abstract: A device for evacuating into the ambient air combustion products from a condensation boiler, in which at least one downstream section of the conduit for evacuating the combustion products is coaxial to the conduit for admission of the combustion air necessary for the burner. Means are provided for returning to the outside a fraction of the air collected in said admission conduit. The downstream section of the conduit for evacuating the combustion products, the coaxial section of the admission conduit and the means for returning to the outside a fraction of the collected air define a first heat exchanger. Means also are provided for diluting the combustion product with the fraction of collected air, the dilution means being located in the vicinity of the opening for suction of the combustion air and for rejection of the combustion products into the ambient air.