A controller monitors oxygen levels in a bio-fuel fired device and automatically controls dampers, blowers and the like to reduce generation of smoke or other pollutants, thereby promoting proper operation of a catalytic converter.

A method of improving an endothermic process in a furnace utilizing steps a) calibrating the simplified physical model of step c3) by measuring one or more tube temperature for at least a tube impacted by the throttling of a burner in standard and in throttled state, b) acquiring information on a tube temperature for the tubes present in the furnace with all the burners present in the furnace under standard non-throttled conditions, c) getting a map of burners to throttle including c1) choosing at least one parameter representative of the performances of the furnace with a target of improvement, c2) choosing at least one or more power ratio for the burner throttling, c3) utilizing the information of step b) and a simplified physical model of the impact of throttling a burner on the tube temperature, c4) getting a map of burners to throttle, step d) throttling the burners.

A portable catalytic combustion heater, wherein fuel vapor (11) and air (10) are supplied to a catalyst (6) which promotes the flameless combustion of fuel and releases that. The fuel is supplied as a liquid, passes through a selectively permeable membrane (8) such that fuel vapor exits the membrane and is fed to the catalyst (6). Additional features include porous supports and means of enhancing and diminishing the catalytic rate of combustion and controlling the heat output.