A fire-rated ventilation duct system and improvements therein. According to an embodiment, the fire-rated ventilation duct section comprises, an inner liner configured as conduit for air movement, the inner liner comprising a metallic material and having a first end and a second end, and the first end including a first connection section, and the second end including a second connection section; an outer casing configured for encasing the inner liner, the outer casing comprising a metallic material having a fire-rating, the outer casing having a first end and a second end, and the first end including a first duct connection section configured for joining one end of a second fire-rated ventilation duct, and the second end including a second duct connection section configured for joining one end of a third fire-rated ventilation duct; an insulation layer configured to provide a thermal insulation layer between the inner liner and the outer casing, and the first connection section of the inner liner further comprising a first liner spacer and the second connection section of the inner liner further comprising a second liner spacer, the first and the second liner spacers being configured to define a cavity for receiving and positioning said insulation layer between an outer surface of the inner liner and an inner surface of the outer casing; the first duct connection section of the outer casing being configured to attach to at least a portion of the first connection section of the inner liner, and the second duct connection section of the outer casing being configured to attach to at least a portion of the second connection section of the inner liner to form a sealed duct section.

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.

A ducting system for a heating ventilation and air conditioning (HVAC) application includes a duct assembly having an inner duct member, and an outer duct member disposed around the inner duct such that the outer and inner duct members together define a pre-determined amount of space therebetween. The ducting system also includes a bonding and insulation composite that is disposed in the pre-determined amount of space between the inner and outer duct members to insulate the inner and outer duct members from each other yet adhesively bond with each of the inner and outer duct members for imparting structural rigidity to the duct assembly.

The present double walled grease duct includes a tubular outer shell surrounding a tubular inner liner, wherein a spacer is positioned perpendicular to the walls of the outer shell and the inner liner. The spacer can include a plurality of vertical metal strips extend from a top edge of the spacer to the bottom edge of the spacer, wherein the top edge of the spacer contacts the walls of the outer shell and wherein the bottom edge of the spacer contacts the walls of the inner liner. The metal strips resist the different rates of thermal expansion between the outer shell and inner liner ultimately preventing the collapse of the inner liner under pressure from thermal expansion.

A fire-rated exhaust duct system comprising a modular configuration or structure. The fire-rated exhaust duct system comprises a plurality of exhaust duct sections. Each of the exhaust duct sections is configured to be joined or connected with other exhaust duct sections in the field or at an installation site, e.g. in building housing a kitchen facility or a laboratory facility to form longer sections or runs for exhaust duct system.

A duct includes a rigid air-permeable tube of composite material. The duct also includes a layer of insulation coupled to an exterior surface of the rigid air-permeable tube. The duct further includes a non-rigid insulation layer in contact with the layer of insulation. The non-rigid insulation layer forms an air-impermeable duct wall.

A fire-rated ventilation duct system and improvements therein. According to an embodiment, the fire-rated ventilation duct section comprises, an inner liner configured as conduit for air movement, the inner liner comprising a metallic material and having a first end and a second end, and the first end including a first connection section, and the second end including a second connection section; an outer casing configured for encasing the inner liner, the outer casing comprising a metallic material having a fire-rating, the outer casing having a first end and a second end, and the first end including a first duct connection section configured for joining one end of a second fire-rated ventilation duct, and the second end including a second duct connection section configured for joining one end of a third fire-rated ventilation duct; an insulation layer configured to provide a thermal insulation layer between the inner liner and the outer casing, and the first connection section of the inner liner further comprising a first liner spacer and the second connection section of the inner liner further comprising a second liner spacer, the first and the second liner spacers being configured to define a cavity for receiving and positioning said insulation layer between an outer surface of the inner liner and an inner surface of the outer casing; the first duct connection section of the outer casing being configured to attach to at least a portion of the first connection section of the inner liner, and the second duct connection section of the outer casing being configured to attach to at least a portion of the second connection section of the inner liner to form a sealed duct section.

Provided are a flexible insulated air duct and a modular flexible insulated air-duct system; the flexible insulated air duct includes an air-duct main body (1); the air-duct main body (1) includes an inner air-duct layer (5) and a heat-insulating layer (4) integrally formed on the inner air-duct layer (5); the inner air-duct layer (5) is arranged inside the heat-insulating layer (4l), and the heat-insulating layer (4) is a rubber/plastic material. The modular flexible insulated air-duct system made by assembling a main air duct (7), a branched air duct (8), and a connecting air duct (9) may be rapidly connected on-site using a zip fastener to form an air-duct system having any configuration.

A thermal energy storage device that includes an air distribution conduit and a phase change material. The phase change material is embedded or integrated onto at least an outer portion or inner portion of the air distribution conduit. The energy storage system for buildings includes the thermal energy storage device and an air distribution apparatus that provides air into the device, which is in fluid communication with the air distribution apparatus.

A heating, ventilation, and air conditioning (HVAC) system for a structure having at least one area to be conditioned includes a blower configured to force an airflow through the HVAC system and a duct assembly in airflow communication with the blower. The duct assembly includes a first duct defining a flow path for a first fluid having a first temperature and a second duct having a hollow interior defining a flow path for a second fluid having a second temperature different from the first temperature. The first duct is arranged within the hollow interior of the second duct such that heat is transferred between the first fluid and the second fluid. At least one of the first duct and the second duct is formed from a collapsible material.