Pliable Air Duct Internal Framework to Prevent Sagging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Metal air ducts in buildings can lead to condensation issues, mold growth, and uncomfortable drafts due to their rigidity, and flexible fabric ducts sag when pressure is lost, causing aesthetic and operational problems.
Innovation Solution
The use of internal frameworks within pliable air ducts that maintain tension and shape, even when depressurized, to prevent sagging and noise associated with pressure changes, while also ensuring the duct remains taut and functional.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If flexible fabric ducts are used to prevent condensation and mold, then thermal conductivity is reduced and airflow distribution is improved, but the duct sags when pressure is lost causing aesthetic and operational problems
Solution Approach 1:
The patent uses a flexible fabric duct with an internal framework that maintains the duct's cylindrical shape even when depressurized. The framework consists of flexible ribs that prevent sagging while allowing the outer fabric shell to remain flexible for condensation prevention. This resolves the contradiction by combining flexible material properties with structural support elements.
Solution Approach 2:
The internal framework is divided into multiple discrete flexible ribs spaced along the duct length. Each rib independently supports the duct wall, preventing sagging while maintaining overall flexibility. The segmented structure allows the duct to maintain shape without requiring a completely rigid internal structure.
2Shape
If rigid metal ducts are used for structural stability, then shape maintenance is improved, but condensation and mold problems occur due to high thermal conductivity
Solution Approach 1:
The patent employs a composite structure combining flexible fabric material with an internal framework of flexible ribs. The fabric layer provides thermal insulation to prevent condensation, while the framework provides structural support to maintain shape. This composite approach resolves the contradiction between shape maintenance and condensation prevention.
3Ease of operation
If fabric ducts are used to disperse airflow evenly, then thermal comfort is improved, but loud popping sounds occur when the duct re-inflates after deflation
Solution Approach 1:
The internal framework is pre-installed within the fabric duct during manufacturing, maintaining the duct's cylindrical shape even when depressurized. This preliminary structural support prevents the fabric from collapsing completely, so when pressure is restored, the duct re-inflates gradually without sudden popping sounds while maintaining even airflow distribution.
Data Source
AI summary
Pliable-wall air ducts with internal expanding structures are disclosed. An example air duct system includes a shaft to be disposed within an air duct, to extend in a longitudinal direction, and to be in longitudinal compression. The air duct system also includes a plurality of ribs to be coupled to the shaft and to engage an inner surface of the air duct and a spring to be disposed within the air duct, the spring to be coupled to the shaft. The spring under stress being a contributing factor in both the shaft being in longitudinal compression and the air duct being in longitudinal tension.