| 摘要 |
An HVAC duct is provided. The duct (10, 30) includes an outer tube having a fully continuous external perimeter. The duct (10, 30) further includes an inner tube capable of conveying forced air. The inner tube extends within the outer tube longitudinally. The duct (10, 30) also includes a plurality of support elements (14) spanning between the outer tube (11, 31) and the inner tube (12, 32). The elements (14) extend along the outer tube and the inner tube longitudinally. The elements define a plurality of channels between the outer tube (11, 31) and the inner tube (12, 32). The outer tube, the inner tube, and the elements are fully unitary. |
