Combustion characteristics and thermal efficiency for premixed porous-media types of burners

► Emission characteristics and thermal efficiency for metal fiber (MF), ceramic (CM) and stainless-steel fin (SF) were compared. ► Three porous media-burners were tested with various equivalence ratios and burner capacities to apply the condensing boiler. ► A smaller burner porosity produced higher CO emissions and lower thermal efficiencies. ► The appropriate burner material was metal fiber and the optimal equivalence ratio was 0.80 in this experimental range.