Thermal Performance Design Of Curtain Wall

In recent years, the world has witnessed frequent extreme weather events, and the greenhouse effect has become increasingly pronounced. As a result, more and more countries have begun to focus on climate issues. Against this backdrop, energy conservation and emission reduction have emerged as a critical agenda. In the planning of energy-saving and emission-reduction efforts, building energy efficiency has become an indispensable and vital component.

The energy efficiency of buildings is influenced by many factors, and the Thermal Performance of curtain walls is undoubtedly one of the most critical and impactful aspects. As societal focus on building energy efficiency grows, the Thermal Performance of curtain walls has become an unavoidable and vital topic. 

So, how should the Thermal Performance of curtain walls be designed to meet requirements?

1.Glass

Glass is undeniably the most critical and visually dominant factor in the Thermal Performance of curtain walls, as it typically constitutes the largest surface area of the system. The selection of glass types significantly impacts the final energy efficiency outcomes. To enhance thermal insulation, designers can opt for ‌double- or triple-glazed insulated glass units (IGUs)‌, replacing the air in the cavities with ‌argon gas‌ to further reduce thermal conductivity‌.

The application of ‌Low-E (low-emissivity) coatings‌ is another key strategy. These coatings not only adjust the glass's color, light transmittance, and reflectivity but also substantially improve thermal insulation‌. Low-E films are available in ‌single-silver or double-silver variants‌, with single or double layers, allowing customization based on performance needs‌.

Additionally, ‌warm-edge spacer bars‌ (e.g., silicone foam or hybrid materials) minimize thermal bridging at the glass edges, further enhancing overall insulation‌.

Ultimately, the glass configuration should be tailored to the building's ‌energy efficiency requirements and budget constraints‌, balancing cost-effectiveness with performance‌.

2.Frame

The curtain wall frame is another critical factor affecting Thermal Performance, primarily determined by whether the frame interrupts thermal bridging. Typically, ‌nylon-based thermal break inserts‌ are added to the frame to enhance insulation. The larger the size of the thermal insulation strip (mainly its depth), the better the insulation effect. However, even with thermally improved profiles, their performance cannot match well-configured glass in terms of thermal efficiency. Therefore, for high overall insulation requirements, it is essential to ‌minimize the frame's area ratio‌—achieved by ‌increasing the curtain wall's grid spacing‌ (i.e., larger glass panels with fewer frames).

3.Construction

The construction of curtain walls significantly impacts Thermal Performance. The primary requirement is to ‌maintain continuity of the glass-formed thermal barrier‌, ensuring the ‌thermal break (insulation strip) is positioned within the glass thickness range‌. If the thermal break is placed ‌outside the glass plane or on the interior side‌, its effectiveness is compromised.

Between the curtain wall and the structure, as well as in gaps between curtain wall panels, ‌thermal bridging becomes a critical weak point‌. Design solutions must include ‌sealing and insulation measures‌ to ensure overall Thermal Performance.

For non-glass panel areas (e.g., aluminum cladding), ‌insulation strategies‌ should be tailored: Apply ‌rock wool insulation on the interior side of the aluminum panels‌. Or Integrate ‌structural insulation‌ (e.g., thermal breaks or insulated backing) to minimize heat transfer.

4.Support

The Thermal Performance of curtain walls is also influenced by auxiliary materials. ‌Gaps between glass panels and framing‌ must be filled with ‌high-performance elastic sealants‌ (e.g., silicone or polyurethane) to minimize thermal bridging. In ‌unitized curtain walls‌, various ‌gaskets and weather strips‌ serve as the ‌first line of thermal defense‌. Additionally, in ‌inter-floor zones and edge joints‌, the use of ‌insulation materials like rock wool and foam sealants‌ is critical. The performance of these auxiliary materials directly impacts the overall thermal efficiency, making their selection equally vital.

Ultimately, the ‌Thermal Performance of a curtain wall‌ is a ‌complex yet integrated system‌—only when all components function cohesively can the required thermal standards be met.

REXI have very rich experience in the field of Thermal Performance Design, As you can see, our designers are very experienced and talented，And we also have many excellent completed works, If you are interested in Thermal Performance Design Of Curtain Wall, please contact us.