I-air duct flue gas heater iyisisetshenziswa esisetshenziswa ngokukhethekile ukushisisa nokwelapha igesi ye-air duct flue. Imvamisa iqukethe izinto zokushisa, amadivaysi okulawula namagobolondo, njll., futhi ingasetshenziswa kabanzi ezindaweni ezihlukene zezimboni, izishisi, izitshalo zamandla kanye nezinye izindawo lapho igesi ye-flue idinga ukukhishwa khona. Ngokushisisa i-flue gas ezingeni lokushisa elithile, izinto eziyingozi ezinjengomswakama, ama-sulfide, nama-nitrogen oxides egesini yomkhuhlane zingasuswa ngokuphumelelayo ukuze kuhlanzeke umoya futhi kunciphise ukungcola.