Abstract: To provide a dew-condensation preventing square duct which is capable preventing dew condensation on the duct without winding a heat insulating material around the duct. A dew-condensation preventing square duct includes: an external square duct formed by four plate-shaped external wall portions and having a substantially quadrilateral barrel shape; an internal square duct formed by four plate-shaped internal wall portions and having a substantially quadrilateral barrel shape, the internal square duct being arranged inside of the external square duct; and a holding protrusion which holds the internal square duct inside of the external square duct such that a heat insulating layer S between the external square duct and the internal square duct has a predetermined thickness T.

Abstract: To provide a dew-condensation preventing square duct which is capable preventing dew condensation on the duct without winding a heat insulating material around the duct. A dew-condensation preventing square duct includes: an external square duct formed by four plate-shaped external wall portions and having a substantially quadrilateral barrel shape; an internal square duct formed by four plate-shaped internal wall portions and having a substantially quadrilateral barrel shape, the internal square duct being arranged inside of the external square duct; and a holding protrusion which holds the internal square duct inside of the external square duct such that a heat insulating layer S between the external square duct and the internal square duct has a predetermined thickness T.

Abstract: A duct flange structure which has a higher strength and which is easier to handle and manufacture. The duct flange structure is arranged in an end portion of a duct body having a substantially quadrilateral shape in section that includes a flange portion formed by bending an extension portion extending from an opening edge of each of wall plates constituting the duct body, the flange portion being constituted by a vertical portion extending outside substantially vertically to the wall plate and a horizontal portion extending substantially parallel to the wall plate from the vertical portion, the vertical portion and the horizontal portion being formed by folding and superposing the extension portion in two layers so as to form two adjacent wall portions.

Abstract: A pipe coupling structure is capable of coupling pipes together without driving a screw and using a tool. An example pipe coupling structure includes a first engagement portion formed in an end portion of a first air-conditioning duct. The first engagement portion extends in the circumferential directions and protrudes inside of the first air-conditioning duct. A second engagement portion is formed in an end portion of a second air-conditioning duct. The second engagement portion extends in the circumferential directions and protrudes outside of the second air-conditioning duct. When the end portion of the second air-conditioning duct is inserted into the end portion of the first air-conditioning duct, the second engagement portion climbs over the first engagement portion, and thereby the first engagement portion and the second engagement portion engage each other.

Abstract: To provide a pipe coupling structure capable of coupling pipes together without driving a screw and using a tool. [Means for solving the Problems] A pipe coupling structure includes: a first engagement portion 12 formed in a one-end portion 1A of a first air-conditioning duct 1, the first engagement portion 12 extending in the circumferential directions and protruding inside of the first air-conditioning duct 1; and a second engagement portion 23 formed in a one-end portion 2A of a second air-conditioning duct 2, the second engagement portion 23 extending in the circumferential directions and protruding outside of the second air-conditioning duct 2, and the one-end portion 2A of the second air-conditioning duct 2 being insertable into the one-end portion 1A of the first air-conditioning duct 1.

Abstract: [Problems] To provide a duct flange structure which has a higher strength and which is easier to handle and manufacture. [Means for solving the Problems] A duct flange structure which is arranged in an end portion of a cylindrical duct body 2 having a substantially quadrilateral shape in section, includes: a flange portion 4 formed by bending an extension portion 30 extending from an opening edge 3A of each of wall plates 3 constituting the duct body 2, the flange portion 4 being constituted by a vertical portion 41 extending outside substantially vertically to the wall plate 3 and a horizontal portion 42 extending substantially parallel to the wall plate 3 from the vertical portion 41, the vertical portion 41 and the horizontal portion 42 being formed by folding and superposing the extension portion 30 in two or more.

Abstract: [Problems] To provide a duct flange structure which has a higher strength and which is easier to handle and manufacture. [Means for solving the Problems] A duct flange structure which is arranged in an end portion of a cylindrical duct body 2 having a substantially quadrilateral shape in section, includes: a flange portion 4 formed by bending an extension portion 30 extending from an opening edge 3A of each of wall plates 3 constituting the duct body 2, the flange portion 4 being constituted by a vertical portion 41 extending outside substantially vertically to the wall plate 3 and a horizontal portion 42 extending substantially parallel to the wall plate 3 from the vertical portion 41, the vertical portion 41 and the horizontal portion 42 being formed by folding and superposing the extension portion 30 in two or more.

Abstract: A duct is provided which there is no need to attach any reinforcing material to. This duct has a hollow 5 formed by joining a plurality of flat wall plates 11 to 14 so that the interior surfaces of the wall plates 11 to 14 face each other. The duct is provided with four folded portions including a strip-shaped folded portion 11C, 12C formed by folding each wall plate 11 to 14 on the side of the exterior surface of each wall plate 11 to 14.

Abstract: A duct is provided which there is no need to attach any reinforcing material to. This duct has a hollow 5 formed by joining a plurality of flat wall plates 11 to 14 so that the interior surfaces of the wall plates 11 to 14 face each other. The duct is provided with four folded portions including a strip-shaped folded portion 11C, 12C formed by folding each wall plate 11 to 14 on the side of the exterior surface of each wall plate 11 to 14.

Abstract: An object of the present invention is to provide an air-conditioning duct unit capable of being made compact when transported to largely reduce the cost of transport inside and outside a building as well as the cost of transportation by a truck. A duct unit A of the present invention has upper and lower wall portions 1 and 3 and right and left wall portions 2 and 4 formed of metal sheets, and spin locks curved into a curled shape, the spin locks being provided on the wall portions 1 to 4 at two side edges of the same along the longitudinal direction. One of the pair of spin locks provided on each adjacent pair of the wall portions is inserted in the other to form one of lock joints 9-1 to 9-4 rotatably. The wall portions 1 to 4 are linked so that the duct unit A can be changed in shape. Consequently, the duct unit can be folded so as to be flattened.

Abstract: An object of the present invention is to provide an air-conditioning duct unit capable of being made compact when transported to largely reduce the cost of transport inside and outside a building as well as the cost of transportation by a truck. A duct unit A of the present invention has upper and lower wall portions 1 and 3 and right and left wall portions 2 and 4 formed of metal sheets, and spin locks curved into a curled shape, the spin locks being provided on the wall portions 1 to 4 at two side edges of the same along the longitudinal direction. One of the pair of spin locks provided on each adjacent pair of the wall portions is inserted in the other to form one of lock joints 9-1 to 9-4 rotatably. The wall portions 1 to 4 are linked so that the duct unit A can be changed in shape. Consequently, the duct unit can be folded so as to be flattened.