Abstract: An air duct system includes a conical fabric filter disposed within a cylindrical air duct. In some embodiments, both the filter and the air duct are inflatable. A fabric collar and a pair of zippers not only allow the filter to be readily removed for cleaning, but also allow the air duct system to continue operating with the filter removed. Pleats can provide the filter with more surface area, and the pleats can be interconnected in an alternating pattern to inhibit the filter from over-inflating.

Abstract: A fabric air duct of an HVAC system includes a discharge air register with an air deflector that extends along the length of the duct. Rotating or twisting the deflector adjusts the volume and/or direction of the air being discharged from the register. Even though the deflector is disposed inside the duct, the deflector can be twisted or rotated by manipulating the exterior fabric wall of the duct.

Abstract: An air duct system includes a conical fabric filter disposed within a cylindrical air duct. In some embodiments, both the filter and the air duct are inflatable. A fabric collar and a pair of zippers not only allow the filter to be readily removed for cleaning, but also allow the air duct system to continue operating with the filter removed. Pleats can provide the filter with more surface area, and the pleats can be interconnected in an alternating pattern to inhibit the filter from over-inflating.

Abstract: A fabric air duct with main discharge openings includes additional, much smaller openings that help ventilate the surface of the duct. Ventilating the surface of the duct with a slight yet even amount of airflow helps inhibit the accumulation of condensate and dust on the surface of the duct. In some embodiments, the duct includes a pliable sheet consisting of a rather porous fabric base material. To achieve an appropriately low level of airflow, a plastic coating on the fabric reduces, but does not eliminate the fabric's porosity. A calendering process then reduces the porosity even further. In some embodiments, the calendering process occurs before the plastic coating process. In other embodiments, the pliable sheet is substantially air impermeable, except for its main discharge openings. The sheet is then perforated with numerous smaller openings to achieve the desired amount of surface ventilation.

Abstract: A fabric flow restriction and method for conveying a volume of air through a fabric duct prevents the violet popping that may occur with a fabric duct upon start-up. The fabric ducts are air permeable and/or include discharge openings that evenly disperse supply air from within the duct to a room being heated, cooled, ventilated, or otherwise conditioned by the air. The ducts are typically in a collapsed positioned prior to blower start-up. With the initial airflow, the ducts quickly fill with air and may make a popping sound at their distal ends as the airflow fills the entire fabric duct. The flow restrictions disclosed may be formed of a flexible fabric that has an airflow resistance that varies with radius across the flexible fabric. The flow restrictions may have a first region and a second region each with different resistances, for example. Varying the resistance across the fabric flow restriction reduces or eliminates the popping condition.

Abstract: An air duct system includes a conical fabric filter disposed within a cylindrical air duct. In some embodiments, both the filter and the air duct are inflatable. A fabric collar and a pair of zippers not only allow the filter to be readily removed for cleaning, but also allow the air duct system to continue operating with the filter removed. Pleats can provide the filter with more surface area, and the pleats can be interconnected in an alternating pattern to inhibit the filter from over inflating.