Abstract: The invention provides a pre-insulated duct having a length and comprising a tube having a foam layer. The pre-insulated duct has an interior face and an exterior face and a thickness defined as a distance between the interior face and the exterior face. The interior face of the pre-insulated duct bounds an airflow space. In the present group of embodiments, the pre-insulated duct has a mounting rail system extending along the length of the pre-insulated duct. The mounting rail system includes at least one mounting rail, and preferably a plurality of mounting rails, positioned on (e.g., positioned on an exterior of) the pre-insulated duct.

Abstract: The invention provides a pre-insulated duct having a length and comprising a tube having a foam layer. The pre-insulated duct has an interior face and an exterior face and a thickness defined as a distance between the interior face and the exterior face. The interior face of the pre-insulated duct bounds an airflow space. In the present group of embodiments, the pre-insulated duct has a mounting rail system extending along the length of the pre-insulated duct. The mounting rail system includes at least one mounting rail, and preferably a plurality of mounting rails, positioned on (e.g., positioned on an exterior of) the pre-insulated duct.

Abstract: The invention provides an HVAC duct having an inner composite tube and an outer composite tube. The inner composite tube has an interior metal wall, a primary foam wall, and an exterior metal wall. The outer composite tube has an interior metal wall, a secondary foam wall, and an exterior metal wall. In certain embodiments, the inner composite tube is nested inside the outer composite tube in an end-offset configuration. In these embodiments, the first end of the duct defines a male detent having a radially-outward-facing metal engagement face projecting beyond the interior metal wall of the outer composite tube, whereas the second end of the duct defines a female detent having a radially-inward-facing metal engagement face projecting beyond the exterior metal wall of the inner composite tube. Also provided is an HVAC ductwork assembly wherein two ducts of the described nature are connected in an advantageous end-to-end manner.

Abstract: The invention provides an HVAC duct having an inner composite tube and an outer composite tube. The inner composite tube has an interior metal wall, a primary foam wall, and an exterior metal wall. The outer composite tube has an interior metal wall, a secondary foam wall, and an exterior metal wall. In certain embodiments, the inner composite tube is nested inside the outer composite tube in an end-offset configuration. In these embodiments, the first end of the duct defines a male detent having a radially-outward-facing metal engagement face projecting beyond the interior metal wall of the outer composite tube, whereas the second end of the duct defines a female detent having a radially-inward-facing metal engagement face projecting beyond the exterior metal wall of the inner composite tube. Also provided is an HVAC ductwork assembly wherein two ducts of the described nature are connected in an advantageous end-to-end manner.