As a leading supplier of aluminium curtain walls, I’ve witnessed firsthand the elegance and functionality these architectural marvels bring to modern buildings. In this blog, I’ll break down the structure of an aluminium curtain wall, highlighting its key components and their roles. Aluminium Curtain Wall
Basic Concept of Aluminium Curtain Wall
An aluminium curtain wall is a non – load – bearing exterior cladding system that is attached to the building structure. It acts as a protective shield against the elements while enhancing the aesthetic appeal of the building. Unlike traditional walls, it doesn’t support the weight of the building above but relies on the building’s framework for support.
Key Components of an Aluminium Curtain Wall
Frame System
The frame system forms the backbone of the aluminium curtain wall. It consists of vertical mullions and horizontal transoms, both made of aluminium extrusions. These extrusions are manufactured with high precision to ensure a perfect fit and alignment.
- Mullions: Vertical mullions are the primary load – carrying members of the curtain wall. They are designed to withstand wind loads, seismic forces, and their own self – weight. Mullions are typically connected to the building structure at intervals, using brackets or anchors. The connection details are critical, as they must allow for some degree of movement to accommodate thermal expansion and contraction of the building.
- Transoms: Horizontal transoms are installed between the mullions to provide additional support and divide the curtain wall into smaller panels. They help in distributing loads evenly across the curtain wall and also play a role in the overall structural integrity. Transoms are usually connected to the mullions through mechanical joints, which can be either hidden or visible depending on the architectural design.
Glazing Units
Glazing units are a prominent feature of aluminium curtain walls, contributing to both the visual appearance and the performance of the system.
- Glass Types: There are several types of glass used in curtain wall glazing, each with its own set of properties. Float glass is the most basic type and is commonly used for its clarity. Tempered glass is heat – treated to increase its strength and safety. When broken, tempered glass shatters into small, blunt pieces, reducing the risk of injury. Laminated glass consists of two or more layers of glass bonded together with a plastic interlayer. It offers excellent security and sound insulation properties.
- Insulating Glass Units (IGUs): Most modern aluminium curtain walls use insulating glass units to improve energy efficiency. An IGU typically consists of two or more glass panes separated by a spacer. The space between the panes is filled with a dry gas, such as argon or krypton, which acts as an insulator, reducing heat transfer through the glass.
Sealing and Gaskets
To prevent water ingress, air leakage, and the transmission of sound, proper sealing is essential in an aluminium curtain wall.
- Gaskets: Gaskets are made of elastomeric materials such as EPDM (ethylene propylene diene monomer) or silicone. They are installed at the joints between the frame members and the glazing units. Gaskets create a watertight and airtight seal, preventing moisture from entering the building and reducing energy loss.
- Sealants: In addition to gaskets, sealants are used to fill the gaps between the components of the curtain wall. Silicone sealants are commonly used due to their excellent weather resistance, flexibility, and adhesion properties. They are applied to the joints and seams to provide an additional layer of protection against water and air infiltration.
Drainage System
Even with proper sealing, some water may still find its way into the curtain wall system. A well – designed drainage system is crucial to ensure that any water that enters the wall is quickly removed.
- Drainage Channels: Drainage channels are built into the frame system to collect and direct water to the exterior of the building. They are typically located at the bottom of the curtain wall panels and are sloped to allow water to flow freely.
- Weep Holes: Weep holes are small openings in the frame that allow water to drain out. These holes are strategically placed to ensure that water is removed from the wall cavity before it can cause damage.
Accessories
Accessories play a supporting role in the overall functionality and appearance of the aluminium curtain wall.
- Sunshades: Sunshades are used to control solar heat gain and reduce glare. They can be fixed or adjustable and are typically made of aluminium or other lightweight materials. Sunshades not only improve the energy efficiency of the building but also add an architectural element to the curtain wall.
- Ventilation Louvers: Ventilation louvers are used to provide natural ventilation and air circulation in the building. They can be designed to be operable or fixed, depending on the ventilation requirements. Louvers are often integrated into the curtain wall system to maintain the overall aesthetic appearance.
- Lighting Fixtures: Lighting fixtures can be incorporated into the curtain wall to enhance the building’s appearance at night. LED lights are commonly used due to their energy efficiency and long lifespan. They can be installed in the frame or behind the glazing to create a dramatic lighting effect.
Structural Design Considerations
When designing an aluminium curtain wall, several factors need to be taken into account to ensure its structural integrity and performance.
- Wind Loads: Wind is one of the major loads that an aluminium curtain wall must withstand. The design of the frame system and the glazing units must be able to resist the pressure exerted by the wind. Engineers calculate the wind loads based on the building’s location, height, and shape, and then design the curtain wall accordingly.
- Seismic Forces: In earthquake – prone areas, the curtain wall must be designed to withstand seismic forces. The connection between the curtain wall and the building structure must allow for some movement during an earthquake to prevent damage to the wall.
- Thermal Expansion and Contraction: Aluminium has a relatively high coefficient of thermal expansion. This means that the curtain wall will expand and contract with changes in temperature. The design must allow for this movement to prevent warping or damage to the wall. Expansion joints are often incorporated into the frame system to accommodate thermal movement.
Quality Assurance and Testing
As a supplier, we take quality assurance very seriously. Before our aluminium curtain walls are installed on a building, they go through a series of rigorous tests.
- Water Penetration Tests: These tests simulate different weather conditions to ensure that the curtain wall is watertight. Water is sprayed onto the wall at a specified pressure, and the inside of the wall is inspected for any signs of leakage.
- Air Infiltration Tests: Air infiltration tests measure the amount of air that can pass through the curtain wall. The goal is to minimize air leakage to improve energy efficiency and indoor comfort.
- Structural Load Tests: Structural load tests are conducted to verify that the curtain wall can withstand the expected loads, such as wind and seismic forces. The wall is subjected to various loads in a test laboratory, and its performance is monitored.
Conclusion
The structure of an aluminium curtain wall is a complex and sophisticated system that combines functionality, aesthetics, and durability. Each component plays a crucial role in ensuring the overall performance of the wall. As a supplier, we are committed to providing high – quality aluminium curtain wall solutions that meet the needs of our customers.
If you are in the market for an aluminium curtain wall for your next building project, we are here to help. Our experienced team can assist you in designing a curtain wall that not only meets your structural requirements but also enhances the visual appeal of your building. Contact us to discuss your project and start the procurement process.
References
Aluminum Wall Panels Awbi, H.B. (2003). Ventilation of Buildings. Spon Press.
ASHRAE. (2017). ASHRAE Handbook: Fundamentals. American Society of Heating, Refrigerating and Air – Conditioning Engineers.
National Building Code of Canada (NBCC). (2015). Canadian Commission on Building and Fire Codes.
Zhejiang Ouzhijie Aluminium Co., Ltd.
We are one of the most professional aluminium curtain wall manufacturers and suppliers in China, featured by high quality customized products. Please rest assured to wholesale bulk aluminium curtain wall for sale here from our factory. Also, quotation is available.
Address: No.277 Shuguang Road,Tudian Industrial Zone,Tongxiang City, Zhejiang Province, China
E-mail: Ada@ozjpanel.com
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