Blow molded airflow conduit with outer insulation

A method of forming a blow molded plastic article comprising:

• providing an insulation carrier;
• providing a first sheet of insulation material located on the insulation carrier;
• providing a blow molding mold, the blow molding mold including two halves and having a molding surface defining a molding cavity to form the blow molded plastic article, wherein the blow molded plastic article comprises a blow molded airflow conduit;
• locating the insulation carrier between the two halves of the blow molding mold;
• transferring the first sheet of insulation material from the insulation carrier to the blow molding mold such that the first sheet of insulation material overlies at least a first portion of the molding surface of the blow molding mold;
• introducing an extrudate of thermoplastic composition between the two halves of the blow molding mold;
• closing the blow molding mold;
• forming the extrudate to a shape of the mold cavity of the blow molding mold to form the blow molded plastic article;
• bonding the extrudate to the first sheet of insulation material overlying at least a portion of the mold surface of the blow molding mold as the extrudate is being formed to the shape of the mold cavity;
• and
• forming at least one air inlet and at least one air outlet in the blow molded airflow conduit.