How do plasma flueless gas fires work?
Not sure about the specific ofthe burner you are considering. However any gas fired burner will produce flue gases and if there is no flue then they will enter your room. As suggested in one of the other answers, a catalitic converter makes sure all the gas is burnt and burnt completely so no carbon monoxide thats the poisonous one! only carbon dioxide and water relatively harmless. As mentioned you must have some room ventilation otherwise the carbondioxide will build up and eventually suffocate both you and the fire! Given that it is called plasma fluless… it is possible that a high voltage electric discharge is used to assist the burning(combustion) rather than a catalytic converter, effect is still the same no matter how its done. There is no way to burn gas and not have waste gases as a result. But a very clean burner is possible and the combustion products are not harmful as long as you do not allow them to build up in the room.