Dual-skin facade, its types and applications in different climatic conditions

The application of double-skin façades in many modern buildings has gained increasing attention with the advancement of building technology and new approaches in architecture. The double-skin façade, as one of the latest innovations in the construction industry, plays an important role in improving energy efficiency in buildings and enhancing the comfort conditions for occupants. In today’s world, where sustainable architecture and energy optimization have become the primary concerns for designers and architects, the double-skin façade is presented as a smart and effective solution to address these needs.

In this article, we will examine the different types of this façade, its applications in various climatic conditions, and the advantages and disadvantages of this system, in order to have a deeper understanding of the role of this façade in modern architecture.

Definition of a Double-Skin Facade

First, we will provide a simple and clear definition of a double-skin facade. A double-skin facade (DSF) is an innovative structure in the building envelope system that consists of two separate façade layers, which may be made of different and diverse materials.

Between these two layers, there is an empty space that acts as a thermal and acoustic insulation. This space can be naturally or mechanically ventilated. The main function of this facade is to create a protective layer between the building’s interior space and the outdoor environment.

This protective layer prevents excessive heat from entering in the summer and heat from escaping in the winter. In other words, the double-skin facade acts like a filter and optimizes the thermal comfort conditions inside the building.

This type of facade, due to the empty space between the two layers, acts as a sound insulation and prevents the entry of loud noises into the building. Additionally, it enables the control of natural light and prevents direct sunlight from entering the building.

In terms of energy performance, the double-skin facade plays a very important role. By creating a thermal insulation layer, it prevents energy loss in the building and helps to reduce heating and cooling costs. Additionally, by controlling natural light and reducing the need for artificial lighting, it leads to energy savings. As a result, buildings that utilize this type of facade have better energy performance.

Types of Double-Skin Facades

After providing the initial definition of the double-skin facade, now is the time to introduce its different types. The double-skin facade is designed and implemented in various forms and types, each with its own unique characteristics and applications. The selection of the appropriate facade type depends on various factors, including the climatic conditions, building function, and project budget. The Alom Gostar Engineering Company, considering the engineering issues mentioned, has designed and implemented the required double-skin facade in various projects, the favorable effects of which can be observed during the operational period.

Mechanical Ventilated Double Skin Façade

This type of facade is one of the most common and effective types of double-skin facades, in which the space between the two layers is continuously ventilated, and fresh air is mechanically introduced into this space. This ensures that the air temperature in the cavity between the two layers is close to the ambient temperature, and prevents the creation of a large temperature difference between the building’s internal, intermediate, and external spaces.

The operation of the ventilated facade is as follows: the warm air that is created in the cavity between the two layers due to solar radiation is moved upwards by a fan and is expelled through the vents installed at the top of the facade. Simultaneously, cooler air enters the cavity from the bottom, creating a continuous air flow. This air flow not only helps reduce the temperature of the space between the two layers, but also facilitates the natural ventilation of the building’s interior space.

Natural Ventilated Double Skin Façade

After becoming familiar with the mechanically ventilated double-skin facade, we now need to introduce the passive double-skin facade. The passive double-skin facade is another type in which the ventilation of the air between the two layers is done naturally, without the use of mechanical equipment. In this type of facade, the temperature difference between the building’s interior and exterior spaces, as well as the difference in air density at various points in the space between the two layers, cause the air flow.

The difference between the passive and ventilated double-skin facades is that in the passive double-skin facade, the air ventilation is done naturally and without the need for additional energy, while in the mechanically ventilated double-skin facade, fans or other mechanical equipment are used for the air ventilation. This difference means that the passive double-skin facade is more energy-efficient compared to the ventilated type.

This type of facade has multiple advantages. Firstly, due to the lack of mechanical equipment, the construction and maintenance costs of the passive double-skin facade are lower compared to the ventilated type. Additionally, since it does not require electrical energy, it is considered a sustainable and environmentally-friendly system. Moreover, due to the simplicity of the design and the absence of moving parts, the passive double-skin facade has high reliability and durability.

On the left: The air buffer acts as a barrier to prevent heat loss.

In the middle: The excess heat is expelled through a process called the stack effect.

On the right: Using operable elements, the double-skin facade assists with internal ventilation.

Combined double-shell facade

Familiarizing ourselves with composite double-skin facades will bring us closer to understanding the true capabilities of double-skin facades. As its name suggests, a composite facade combines the characteristics of both types of double-skin facades. In this type of facade, natural and mechanical ventilation methods are used simultaneously, and different materials are used to construct the inner and outer skins. This flexibility in design allows the double-skin facade to adapt to the specific needs of each project.

In a composite double-skin facade, natural ventilation systems might be used in some sections while mechanical ventilation systems are used in other sections.

Due to its high flexibility, composite facades are widely used in complex projects with specific requirements. For example, in high-rise buildings with complex geometry, composite double-skin facades can be used to create a facade with high energy performance and attractive visual aesthetics. Additionally, in buildings located in areas with variable climatic conditions, this type of composite facade can be used to create an intelligent ventilation system that can adapt to changes in temperature and humidity.

Applications of Double-Skin Facades in Different Climatic Conditions

For more information about double-skin facades, you can contact the Research and Development department of Alum Gostar Company and receive your required technical consultation. As an innovative technology in the construction industry, double-skin facades have the ability to adapt to diverse climatic conditions and can play a significant role in improving building energy performance across different regions.

Cold Climate

In cold regions, double-skin facades function as a highly effective thermal insulator. The void space between the two skins creates an insulating air layer that reduces heat transfer from the building’s interior to the exterior by minimizing the temperature difference between the inner and middle layers, consequently reducing heating requirements.

Hot Climate

In hot and dry regions, this facade acts as a natural sunshade, preventing direct sunlight from entering the building and reducing the building’s cooling load. Additionally, the void space between the two skins functions as an air channel, enabling natural ventilation of the building and reducing the relative temperature of the middle layer.

Humid Climate

In humid regions, this type of facade can help improve thermal comfort conditions by controlling the relative humidity inside the building. The double-skin facade effectively reduces indoor relative humidity by creating a barrier against moisture penetration from the exterior to the interior of the building.

Advantages and Disadvantages of Double-Skin Facades

To fully understand the applications of each system, it is necessary to carefully examine its advantages and disadvantages. Double-skin facade, as an innovative technology in the construction industry, offers many benefits; however, it also has some drawbacks. The following will examine both the advantages and disadvantages of this system:

The following are among the most important advantages of double-skin facades:

• Effective thermal insulation: The void space between the two skins creates an insulating air layer that prevents heat transfer and consequently reduces heating and cooling requirements.
• Sound insulation: This facade acts as a highly effective acoustic barrier, preventing external noise pollution from entering the building.
• Natural light control: Using different types of glass and special coatings, it’s possible to control the amount of infrared heat radiation and natural light entering the building.
• Natural ventilation: The void space between the two skins enables natural ventilation of the building.
• Increased building lifespan: The useful life of building materials and mechanical equipment is extended by reducing atmospheric and environmental effects on the building.

The most important disadvantages of double-skin facades include the following:

• High cost: The construction and installation costs of double-skin facades are higher compared to other types of facades.
• Implementation complexity: Its execution requires high expertise and experience, and involves a more complex process compared to other types of facades.
• Heavy weight: Due to the use of two layers of glass and other materials, this facade is heavier than other types of facades, which may affect the building’s structure.
• Maintenance: Maintenance and repairs of double-skin facades are more complex and expensive compared to other types of facades.
• Design limitations: In some cases, using this type of facade may create limitations in interior building design due to the loss of useful interior space.

The Role of Double-Skin Facades in Sustainable Architecture

Understanding the role of double-skin facades in sustainable architecture will help complete our knowledge of double-skin facades. As a key element in sustainable architecture, double-skin facades play a significant role in reducing the environmental impact of buildings. This type of facade significantly reduces building energy consumption by creating a thermal and acoustic insulation layer between the building’s interior and exterior spaces. By reducing the need for heating and cooling systems, greenhouse gas emissions and air pollution are also decreased. Additionally, this facade helps improve indoor air quality and create a healthier environment by controlling natural light and natural ventilation.

Compared to other innovative technologies in sustainable architecture, double-skin facades have unique advantages. For example, compared to traditional HVAC systems, double-skin facades significantly reduce energy consumption by using natural mechanisms. Additionally, compared to other types of thermal insulation, double-skin facades not only provide thermal insulation but also enable other functions such as natural light control and natural ventilation.

Given the mentioned advantages, double-skin facade is recognized as a green and sustainable technology, and its use not only helps reduce the environmental impact of buildings but also leads to improving the quality of life for occupants and increasing the building’s value.

Summary

This article briefly discussed what a double-skin facade is and its role in improving building energy performance and increasing occupant comfort. This facade helps reduce energy consumption, improve indoor air quality, and increase building lifespan by creating a thermal and acoustic insulation layer between the building’s interior and exterior spaces. This technology is particularly applicable in various climatic conditions, including cold, hot, and humid regions, and can be used as an effective solution for achieving sustainable architecture

Architects and designers are recommended to use double-skin facades in the design of new buildings, particularly high-rise buildings and buildings located in regions with specific climatic conditions. Additionally, given the complexities in designing and implementing this type of facade, it is advisable to consult with specialized engineers in this field.

For more information about sustainable architecture and innovative building technologies, you can read our other articles on the website, and if needed, request specialized consultation from the technical engineering or research and development departments of Alum Gostar Company. If you are seeking consultation or specialized services in sustainable building design and energy optimization, please contact us.