Abstract: An apparatus for reducing nitrogen dioxide emissions in a flueless heating appliance or heater includes a heat-exchanger for exchanging heat contained in fumes produced by the combustion of a fuel in the heating appliance. A heating appliance or heater without a fume flue includes a burner supplied with a gaseous fuel, an evacuator for discharging into an environment outside the heater fumes produced by combustion of the fuel, and a heat-exchanger for receiving the fumes from the burner and sending them to the evacuator. A method for reducing nitrogen dioxide emissions in a flueless heating appliance, supplied with a gaseous fuel, includes removing heat in a controlled manner from fumes produced by the combustion of the fuel so as to minimize the conversion of NO into NO2 in the fumes.

Abstract: An apparatus for reducing nitrogen dioxide emissions in a flueless heating appliance comprises heat-exchanger means suitable for being crossed by the fumes produced by the combustion of a fuel in said heating appliance. A heating appliance without a fume flue comprises burner means supplied with a gaseous fuel, evacuation means for discharging into the outside environment fumes produced by the combustion of said fuel and heat-exchanger means suitable for receiving said fumes from said burner means and sending them to said evacuation means. A method for reducing nitrogen dioxide emissions in a flueless heating appliance, supplied with a gaseous fuel, comprises removing heat in a controlled manner from fumes produced by the combustion of said fuel so as to minimize the conversion of NO into NO2 in said fumes.