A few small steps to make your frame style glass curtain wall design more energy-efficient

The energy-saving design of glass curtain walls is not simply 1+1=2, but requires consideration from multiple aspects in order to achieve the desired energy-saving goals. You can consider it from the following four perspectives:

Comprehensive heat transfer coefficient

Now let's get out of this misconception. The heat transfer coefficient of glass refers to the performance of the glass itself and the curtain wall system, which are two different concepts. The overall thermal insulation performance of the curtain wall is reduced due to the heat transfer of the aluminum frame, and there is also air infiltration heat loss due to the inability to completely seal the surrounding area of the opening fan. Therefore, the heat transfer coefficient of glass determines the approximate range of insulation effect, and the comprehensive heat transfer coefficient after considering the heat transfer of profiles and air infiltration is the design parameter that serves as a reference for energy conservation.

The insulation system should be efficient

The building curtain wall should be selected with good thermal insulation performance, and the hidden frame glass curtain wall system is a good choice. It not only completely isolates the outdoor temperature difference, but also avoids the heat loss caused by the aluminum material. But if a transparent frame system is used, aluminum alloy profiles with insulation treatment should be selected or other effective insulation measures should be taken. Usually, bridge cut insulation aluminum profiles are used, or EPDM insulation pads are added between the buckle cover on the outside of the insulated glass and the column on the inside of the glass to block heat conduction.

Blocking heat conduction is key

A thermal bridge refers to the reinforced concrete or metal beams, columns, ribs, and other parts located within the enclosure structures such as exterior walls and roofs. Due to their strong heat transfer ability, dense heat flow, and lower inner surface temperature, these areas are called thermal bridges. Improper handling of the thermal bridge problem can increase its actual heat transfer coefficient, resulting in a significant increase in heat loss through the curtain wall. The reliability of insulation measures mainly depends on whether the solid heat transfer path is effectively blocked, including metal profile sections, metal connectors, screws and other fasteners, and spacing bars at the edges of insulating glass. The thermal insulation nodes of profile sections are mainly achieved by using insulation profiles or insulation pads. The thermal bridge through curtain wall connectors, screws and other fasteners requires the use of insulation pads or conversion connection methods to block the solid heat transfer path. For solid heat transfer treatment of insulating glass edge spacers, non aluminum alloy warm edge spacers can be used as a substitute.

The sealing performance is also good

The airtightness of glass curtain walls can also have a significant impact on energy efficiency. Sealing materials are usually used between glass and profiles, as well as between curtain wall glass, to improve their airtightness. The position around the opening fan is the area with poor sealing effect, and usually the sealing effect of the opening fan should be given special consideration in the design process. Add sealing strips between the opening window sash and the window frame, and add water strips and sealing strips between the window frame and the crossbeam column for multiple seals.