Pepala lopangidwa ndi chitsulo chopangidwa ndi galvanized phenolic air duct ndi chinthu chosinthika chatsopano chamtundu wachitsulo chachitsulo.Chosanjikiza chakunja cha bolodi la duct ya mpweya chimapangidwa ndi mbale yachitsulo chokongoletsedwa ndi malata, wosanjikiza wamkati wokutidwa ndi zojambulazo za anticorrosive aluminiyamu, ndipo chapakati chimapangidwa ndi thovu la phenolic.Kuwonjezera pa ubwino wa miyambo chitsulo pepala mpweya ma ducts wabwino kuuma ndi mkulu mphamvu, alinso katundu wa lawi retardant kutentha kuteteza, mayamwidwe phokoso ndi kuchepetsa phokoso.Komanso, chitoliro chikapangidwa, palibe kutetezedwa kwachiwiri kwa kutentha komwe kumafunikira, komwe kumagonjetsa kufooka kwa njira yachitsulo yachitsulo yomwe mpweya wakunja umawonongeka mosavuta, umakhala ndi moyo wautali wautumiki, ndipo ndi wokongola komanso wowolowa manja.