ETFE View: An Introduction to Modern Technology in Contemporary Architecture

In the dynamic world of modern architecture, the search for high-performance materials with appealing designs continues. One of these innovative materials that has attracted the attention of many architects and engineers in recent years is the ETFE facade. ETFE, known as a fluorocarbon polymer with unique properties, was invented by DuPont in the 1970s and was initially used in the aerospace industry as a lightweight and resistant insulator; however, as time passed and the extraordinary capabilities of this material in architecture were discovered, it quickly found its place in the construction industry and was recognized as a forward-looking material. The ETFE facade, combining transparency, flexibility, light weight, and high resistance to environmental factors, has enabled the creation of structures with complex and geometric designs. These facades, in addition to their visual beauty, have excellent thermal and acoustic performance and are also considered a sustainable and environmentally friendly option. In this article, we will examine this facade in more detail, including its structure, characteristics, advantages, applications, challenges, and the future of this new technology in architecture. Stay with us.

Structure and Composition of ETFE Facade

ETFE facade, as a new technology in modern architecture, has a unique structure and complex composition. These facades consist of several thin and transparent layers of ETFE polymer that function as air cushions or air pockets. These cushions are connected together by a metal or cable structure and are attached to the building facade.

Components of ETFE
To better understand the function and structure of ETFE facade, we need to examine its main components in more detail.

Ethylene Tetrafluoroethylene (ETFE) Polymer
This polymer is the main and basic component of ETFE facade. ETFE is considered an ideal choice for these types of facades due to its unique properties such as high transparency, excellent chemical resistance against environmental factors, light weight, high flexibility, and long lifespan.

Additives
To improve the physical and mechanical properties of ETFE polymer and also increase the lifespan and durability of the facade, various additives are used. The materials include the following:

• Plasticizers: To increase flexibility and reduce polymer brittleness;
• Color stabilizers: To maintain color and prevent discoloration due to sunlight exposure;
• UV protectors: To protect the polymer against ultraviolet rays and prevent its degradation;
• Fire retardants: To increase facade resistance against fire and reduce the speed of fire spread in case of fire.

Adhesives and Sealants
To connect different layers of ETFE to each other and also create watertight connections between layers and the supporting structure, special adhesives and sealants are used. These materials must have very high resistance against environmental factors such as moisture, heat, and UV radiation.

Different Layers in ETFE Facade System
One of the special features of ETFE facade is the presence of several thin and transparent layers of ETFE polymer that are placed on top of each other as cushions. Each of these layers has specific functions that generally help improve the performance and aesthetic appearance of the facade. The types of layers and their functions are:

• Outer layer: This layer is directly exposed to environmental factors such as rain, snow, wind, and sunlight. Therefore, it must have very high resistance against these factors. This layer also acts as a barrier against pollution and prevents dust from penetrating into the facade.
• Middle layers: The middle layers act as thermal and acoustic insulation and lead to reduced energy loss and improved sound quality inside the building. These layers can also act as a light filter and reduce the intensity of light entering the building.
• Inner layer: The inner layer usually serves as a protective layer for the underlying layers and protects them against mechanical damage.

The number of ETFE layers in a facade can vary between two to five layers. Increasing the number of layers improves the thermal and acoustic insulation performance of the facade, increases impact resistance, and also creates diverse visual effects.

Types of ETFE Facade Systems
ETFE facade systems are divided into two main categories based on the number of ETFE polymer layers used in their construction: single-layer and multi-layer. Each of these systems has its own specific characteristics and applications.

Single-layer Systems
In these systems, only one layer of ETFE polymer is used to form the building facade. These types of facades are more popular than multi-layer systems due to their simple construction and lower cost. However, single-layer systems do not perform very well in terms of thermal and acoustic insulation and are mostly used in buildings with basic needs.

In these multi-layer systems, several layers of ETFE polymer are placed on top of each other to form a multi-layer facade. Each of these layers has specific functions and generally helps improve the facade’s performance. Multi-layer systems are more suitable for buildings with greater and more complex needs, such as office, commercial, and sports buildings, due to their better performance in terms of thermal and acoustic insulation and light control.

Physical and Mechanical Properties of ETFE Facade

ETFE facade has created a remarkable transformation in the construction industry due to its unique physical and mechanical properties. In addition to their beautiful and modern appearance, these facades show excellent performance in various weather conditions. Below, we will discuss some of the most important physical and mechanical properties of this facade.

UV and Weather Resistance
One of the most important features of ETFE facade is its very high resistance to ultraviolet (UV) radiation. This feature makes the facade resistant to discoloration, brittleness, and degradation due to long-term sun exposure. Additionally, ETFE is highly resistant to weather conditions such as rain, snow, wind, and temperature changes, and does not deform or lose performance over time.

Light Weight and Flexibility
ETFE facade, due to its very light weight, reduces the dead load of the building and consequently reduces construction costs. Additionally, the high flexibility of this facade enables the creation of complex designs and allows architects to create facades with unique and attractive appearances.

Thermal and Radiation Performance
ETFE facade has excellent thermal performance and prevents energy loss in the building. These facades act as thermal insulation and prevent heat penetration in summer and cold in winter into the building. Additionally, ETFE facade has the ability to control natural light. Using different layers of ETFE with different colors and thicknesses, the amount and intensity of light entering the building can be controlled.

Advantages of Using ETFE Facade

ETFE facade brings numerous advantages to buildings. These benefits have made this facade one of the most popular options for modern buildings. Below, we will discuss some of the most important advantages of using ETFE as a building facade.

• Energy Savings: One of the most important advantages of ETFE facade is its good performance as thermal insulation. These facades help reduce energy consumption for heating and cooling the building by reducing heat transfer between the inside and outside of the building.
• High Durability and Longevity: ETFE facade is highly resistant to environmental factors such as rain, snow, wind, UV radiation, and temperature changes. Also, these facades are resistant to pollution and chemicals and require little maintenance. For this reason, ETFE facade has a very long lifespan and can be used for several decades without requiring major repairs.
• Creative and Complex Design Capabilities: The high flexibility of ETFE facade enables the creation of complex designs. These facades can be built in curved, wavy, or even complex geometric shapes. Additionally, it’s possible to print various designs on this facade, giving buildings a unique and beautiful appearance.
• Environmental Compatibility: This facade is an environmentally friendly option due to its light weight, reduced energy consumption, and recyclability. The use of these facades helps reduce greenhouse gas emissions and air pollution. Also, during the production and installation process, it produces less pollution compared to other building materials.

Applications of ETFE Facade in Architecture

Due to its special characteristics, ETFE facade can be used in a wide range of architectural projects. Below, we will discuss some of the most important applications of ETFE facade in architecture.

Stadiums and Sports Centers
This type of facade is an ideal choice for roofs and facades of stadiums and sports centers due to its ability to create large and bright spaces. These facades provide an open and pleasant space and offer spectators sitting under these roofs a wide view of the playing field. Additionally, the high resistance of ETFE facade to rain and snow enables events to be held in any weather condition.

Commercial Centers and Exhibition Spaces
ETFE facade is very suitable for commercial centers and exhibition spaces due to its ability to create large, column-free spaces. These facades create bright and pleasant spaces that are important for better display of products and services.

Greenhouses and Green Spaces
ETFE facade is very suitable for greenhouses and green spaces due to its high transparency and ability to control the amount and intensity of incoming light. These facades provide the ability to create a controlled environment for plant growth. Additionally, its high resistance to UV radiation protects plants from sun damage.

Office and Residential Buildings
ETFE facade also has widespread use in office and residential buildings. These facades give buildings a modern and beautiful appearance. Additionally, the high thermal and acoustic insulation performance of ETFE facade helps reduce energy consumption and improve residents’ quality of life.

ETFE Facade Design and Installation Process

Due to the complexity of construction and installation, ETFE facade requires a precise and professional design and implementation process. This process includes various stages from initial design to final facade installation. Below, we will examine each stage of ETFE facade installation.

Design Stages and Engineering Calculations
ETFE facade design is a multi-stage process requiring collaboration from a team of various specialists including architects, structural engineers, mechanical engineers, and materials specialists. In the design phase, first, the overall facade design is created based on the building’s functional and aesthetic needs. Then, precise engineering calculations are performed to determine the dimensions, shape, number of layers, and type of connections for the ETFE facade. These calculations must be done considering the loads applied to the facade such as wind load, snow load, and earthquake load to ensure the facade has sufficient strength.

Installation and Implementation Techniques
Installing ETFE facade is a complex and sensitive task requiring high precision and skill. First, the supporting structure is installed on the building. Then, ETFE cushions are inflated using a pump and will be attached to the supporting structure. The connections between cushions and the supporting structure must be designed to be completely waterproof and prevent air and water from penetrating into the building. Also, to create a unified and beautiful appearance, the connections should be designed to be hidden.

Safety Considerations and Standards
Safety is one of the most important factors in designing and installing ETFE facade. Due to the high altitude and special working conditions, appropriate equipment must be used in compliance with safety standards. Additionally, attention must be paid to construction standards and environmental standards to ensure that the facade meets the necessary standards in terms of safety, performance, and environmental impact.

Comparison of ETFE Facade with Other Facade Materials

ETFE facade, as an emerging technology in the construction industry, has unique characteristics that distinguish it from other facade materials. To better understand the advantages and limitations of this facade, comparing it with other common materials, namely glass and polycarbonate, can be helpful.

ETFE versus Glass
We can compare ETFE with glass as follows:

• Weight: ETFE facade is significantly lighter than glass facade. This feature reduces the building’s dead load, reduces construction costs, and facilitates installation.
• Flexibility: ETFE facade can create complex and curved shapes, while glass is more limited to simple geometric shapes.
• Thermal Insulation: Due to its multi-layer structure and properties, ETFE facade has higher thermal insulation compared to glass.
• Impact Resistance: ETFE facade is more resistant to impact and breakage than glass.
• Cost: Generally, the initial installation cost of ETFE facade is higher than glass; however, in the long term, it is more economical due to reduced energy and maintenance costs.

ETFE versus Polycarbonate
The comparison between ETFE and polycarbonate is as follows:

• Transparency: ETFE facade has higher transparency compared to polycarbonate and provides better visibility.
• Weight: ETFE facade is lighter than polycarbonate facade.
• Flexibility: ETFE facade has more flexibility compared to polycarbonate.
• Heat Resistance: ETFE facade is more resistant to intense heat than polycarbonate.
• Cost: The initial installation cost of ETFE facade is usually higher than polycarbonate.

Relative Advantages and Limitations

Like any other technology, ETFE facade also has limitations. High initial installation costs, need for high expertise in design and implementation, sensitivity to scratches, and the possibility of condensation in specific weather conditions are among the limitations of this type of facade.

Costs Associated with ETFE Facade

Due to its advanced technology, ETFE facade usually has a higher initial cost compared to other facade materials. However, considering the advantages of this facade, these costs are justifiable in the long term. Below, we will examine the cost of ETFE facade in more detail.

Initial Installation Costs
The initial installation cost of ETFE facade is usually higher than other facade materials, especially glass. These costs include the costs of procuring and producing ETFE panels, structural design and engineering, installation systems, auxiliary equipment, and skilled labor. Various factors such as project size, design complexity, type and quality of materials used, and geographical location affect the determination of initial costs.

Maintenance and Repair Costs
Due to its high durability and resistance to environmental factors, ETFE facade requires very little maintenance and repair. However, to maintain the facade’s performance and beauty, some periodic maintenance such as cleaning, checking connections, and possible replacement of some parts is necessary. Of course, the maintenance and repair costs of ETFE facade are much lower compared to other facade materials.

Cost-Benefit Analysis Over Building Lifetime
Although the initial installation cost of ETFE facade is high, this cost is compensated over the building’s lifetime. Reduced energy costs due to high thermal insulation, reduced maintenance and repair costs, and increased building lifespan are among the economic advantages of ETFE facade. Additionally, this facade can add to the building’s value due to its beautiful and modern appearance.

Challenges and Limitations of ETFE Facade
Despite its many advantages, ETFE facade also has challenges and limitations. Understanding these issues is essential for better decision-making in facade selection.

• Acoustic Issues: One of the challenges of ETFE facade is environmental noise control. Although this facade is a good sound insulator, spaces requiring complete silence may need additional sound insulation layers.
• Need for Expertise in Design and Implementation: Designing and implementing ETFE facade requires high expertise and experience. Any mistake in design or implementation can lead to serious problems in facade performance and durability.
• Climatic Limitations: In areas with severe temperature changes, moisture may collect inside ETFE panels during cold seasons and appear as water droplets. Although this phenomenon doesn’t damage the building, it affects the facade’s appearance.

Innovations and Future of ETFE Facade
ETFE facade, as a new technology in the construction industry, is constantly advancing and developing. With technological advancement and increased understanding of this material’s unique characteristics, we are witnessing new innovations in this field.

Technological Advances in ETFE Production
With production technology advancement, the quality and variety of ETFE panels have improved. Today, panels with more diverse thicknesses, transparencies, and colors are produced, giving architects the ability to create more complex and creative designs. Also, using new technologies, ETFE panels can be produced with special features such as self-cleaning or color change in response to sunlight.

Integration with Smart Building Systems
ETFE facade easily integrates with smart building systems such as lighting control, ventilation, and shading systems. This integration will increase building energy efficiency, improve occupant comfort, and create a dynamic and smart environment. For example, ETFE panels can be equipped with sensors that automatically adjust the amount of light entering the building.

Emerging Applications in Sustainable Architecture
Due to its unique characteristics, ETFE facade plays an important role in sustainable architecture. This facade is an ideal option for green buildings due to its high thermal insulation, reduced energy consumption, and use of recyclable materials. Additionally, this facade can be used as an active element in energy production. For example, ETFE panels can be used to collect and store solar energy.

Alum Gostar

Alum Gostar is one of the leading companies in designing, manufacturing, and implementing various modern facades, including ETFE facades. This company, utilizing the latest technical knowledge in the world and the experience of its specialists, is able to implement ETFE facades with diverse and complex designs for different buildings. Alum Gostar, by providing a wide range of services including consultation, design, production, and installation, enables its customers to benefit from high-quality ETFE facades with excellent performance. ETFE facades implemented by this company, in addition to visual beauty, offer numerous advantages including high thermal and acoustic insulation, resistance to various weather conditions, and high longevity.

Final Words

ETFE facade, with its special characteristics including light weight, high transparency, flexibility, good thermal and acoustic insulation, and high longevity, has created a massive transformation in the construction industry. This facade has enabled the creation of complex and innovative designs and has given buildings a modern and attractive appearance. In addition to aesthetics, ETFE facade has many functional advantages that have made it an ideal option for sustainable buildings.

Given the technological advances and increased awareness of ETFE facade benefits, it is expected that the use of this facade in the construction industry will expand in the future. The integration of ETFE facade with smart building systems and its application in energy production paints a bright outlook for the future of this new technology. It can be said that ETFE facade is not just a construction technology, but a symbol of innovation and sustainability in contemporary architecture.

References:

https://www.sciencedirect.com/science/article/pii/S0360132321010416

https://www.architen.com/articles/etfe-foil-a-guide-to-design

https://www.architectu.net/media/course/3068/story_content/external_files/HWU_ETFEArch_ADV14_Full.pdf

https://www.archdaily.com/784723/etfe-the-rise-of-architectures-favorite-polymer

https://leichtfrance.com/wp-content/uploads/2020/04/leicht-france-new-etfe-facades.pdf