Independent Sheet Metal, a northern New Jersey firm engaged in the fabrication and installation of sheet metal ductwork for heating, ventilation and air conditioning (HVAC) systems had a customer give them a tough assignment. A large pharmaceutical manufacturer requested a recommendation for a cost-effective corrosive fume exhaust system for their multiple scale organic building project. The request called for several lengths of 60' diameter duct with a long horizontal run located ten stories up on the side of the building. Independent was also told the overall project was over budget and behind schedule!
Careful analysis of all the products available led Independent and their client to the belief that a cost effective solution existed, without sacrificing the corrosion resistant qualities required for the duct.
Research showed that many types of material have been used for corrosive exhaust ductwork, with the most common being plastic. However only a few of the plastic duct products are accepted by the various insurance and code authorities for installation with-out sprinklers inside the duct. Of the approved plastic duct alternatives, athe time needed to prepare, glue and heat-cure each joint (including grinding, sanding, and use of expoxies) would be extremely time consuming and labor intensive for assembly.