ã€China Aluminum Industry Network】 Abstract: This article describes the basic knowledge of heat insulation doors and windows, and the design essentials of heat insulation performance. From the insulation strip shape, seal form, notch design and other aspects are elaborated. Key words: heat insulation, K value, thermal insulation strips, insulation performance of sealing doors and windows is one of the main indicators of the performance of doors and windows, and there are other wind pressure, watertight, airtight, sound insulation and other properties. At present, the state has high requirements for energy efficiency in buildings. The Beijing area has required building energy efficiency to reach 75%, and the K value of doors and windows is less than or equal to 2.0w/(m2k). So how to design the door and window to achieve higher heat insulation performance? The following is a description of strip-type heat insulation profiles. The strip-type heat insulation profile is formed by inserting the bar-shaped heat insulation material (insulation bar) into the aluminum alloy bar through the process of opening teeth, wearing strips and rolling, and making it be firmly engaged by the aluminum alloy profile. Composite profiles. The width of commonly used thermal insulation strip is 14.8mm, 18.6mm, 24.0mm. The wider the width of the thermal insulation strip, the better the insulation effect of the profile. To make the K value of the door and window reach 2.0w/(m2k), the width of the insulation bar is 24.0mm. Wide insulation strip currently Typhoon C has 77.0mm. The shape of the heat-insulating strips is simple I-shaped strips and complex multi-cavity shaped strips. Attention should be paid to the air convection between the heat-insulating strips when using the heat-insulating strips, and the notch problems associated with the functional strips. If the cavity between insulation bars is too large (heat insulation strip width is greater than 24.0mm), it will increase air convection and increase heat conduction. The measures taken are to fill the cavity with foam or to treat it with a sliver or plastic grille to prevent air convection. The function slot of the thermal insulation strip should be designed according to the size of the sealed pressure strip, and a separate slot or aluminum slot should be designed to fit the strip on the single side slot. Because the width of the sealed equal pressure strip is not easy to be firmly connected, the 24.0 mm wide heat insulation strip does not have a snap-in notch, and the aluminum strip is used to achieve the snap-fitting of the strip. Over 24.0mm wide insulation strips should be added to the snap-in notches of the strip. The design of the box fan seals, the heat insulation bar design of the inner window increases the card slot, and can firmly clamp the middle pressure strip. The outer dimensions of the isostatic strips are based on the principle that the cavity between the frame fans is largely filled without affecting the opening, and the shape is as large as possible, which is also to prevent the air flow in the cavity between the frame fans. The isostatic strip form can be designed as a soft and hard co-extruded strip or a separate strip to meet the requirements of a large seal. Corresponding to the equal pressure strip is the insulation strip on the fan, but also to increase its sealing requirements, try to fill the cavity between the frame fan. The slope insulation strip with cavity can be selected at design time, which is better than single T-bar. The amount of sealing overlap between the strip and the heat-insulated strip is controlled to be 3mm, which not only guarantees the amount of lap seal, but also ensures that the strip is not touched during the process of fan opening. Aluminum double-cavity design, in the premise of meeting the mechanical performance requirements, the interior aluminum side cavity as large as possible, the outdoor side aluminum cavity as small as possible, so that the entire door and door warm chambers account for a large proportion, is conducive to energy saving doors and windows . The heat insulation strips of the frame material, fan material, and dip material of the door and window should be on the same plane to keep the isotherm smooth. The glass installation position should be flush with the position of the heat insulation strip. Increasing the size of the cavity between the thermal insulation strips, designing the composite slot of the thermal insulating strip of the frame material to be flush with the edge of the frame material, or using the cover plate to increase the cavity size is also a method of improving the thermal insulation performance of the profile. To improve the thermal insulation performance of doors and windows, glass installation is also required. The main measures are the use of long-tail glass strips and the use of foamed strips around the glass in order to prevent heat conduction between the aluminum of the glass. Increasing the K value of the glass is also a key measure to improve the thermal insulation performance of doors and windows. There is also the filling of foam in the profile cavity, which is not described here. Lear products LR65, LR70, LR75 series, the whole window insulation K value can reach 1.99w / (m2k), 1.75w / (m2k), 1.49w / (m2k). Its design concept is to follow the above-mentioned content and improve the thermal insulation performance of doors and windows.