Fiberglass ducts are composite ventilation duct materials that integrate thermal insulation, sound absorption, and air transport functions, and are widely used in building heating, ventilation, and air conditioning (HVAC) systems. Their performance is not determined by a single material, but rather by the collaborative structure of multiple layers. This article will systematically analyze the material layers and functional relationships of fiberglass ducts from a structural composition perspective.

I. Basic Structural Overview of Fiberglass Ducts

From an overall structural perspective, fiberglass ducts belong to a multi-layered composite structure, typically composed of the following core parts:

1. Inner duct substrate

2. Fiberglass insulation and sound absorption layer

3. Outer protective and reinforcing structure

Each layer plays a specific role in the system, working together to ensure the operational stability of the duct.

II. Inner Layer Structure: Analysis of the Duct Liner

1. Functional Positioning of the Liner

The inner layer of the fiberglass duct is in direct contact with the airflow. Its main functions include:

Forming a stable airflow channel

Reducing air resistance and ensuring air delivery efficiency

Providing basic structural support

2. Characteristics of the Liner Material

The lining layer is usually specially treated to make its surface structure relatively smooth, balancing a certain degree of wear resistance and airflow stability. This layer is not merely a decorative layer, but a crucial foundation for the stable operation of the duct system.

III. Intermediate Layer Structure: Fiberglass Insulation and Sound Absorption Layer

1. Structural Characteristics of the Fiberglass Layer

The core structural layer of the fiberglass duct is the fiberglass insulation and sound absorption layer. This layer is formed by a large number of interwoven fine glass fibers, containing abundant tiny air gaps within.

2. Analysis of the Insulation Mechanism

The fibers and air layers within the fiberglass layer work together to effectively reduce the rate of heat transfer through the duct wall, thereby reducing heat loss.

3. Sound Absorption and Noise Reduction Principle

When sound waves generated by airflow enter the fiberglass structure, the sound energy is reflected multiple times between the fibers and dissipated, thus reducing system noise.

IV. Outer Structure: Analysis of Protective and Reinforcing Layers

1. Main Functions of the Outer Structure

The outer layer of a fiberglass duct typically performs the following functions:

Providing mechanical strength and overall stability

Preventing direct impact of the external environment on the internal structure

Facilitating transportation, installation, and subsequent maintenance

2. Outer Structure Forms

Depending on the usage environment, the outer structure may adopt different forms of protective and reinforcing designs to meet the usage needs of different scenarios such as building interiors or equipment rooms.

V. Advantages of the Composite Structure of Fiberglass Ducts

1. Multifunctional Integrated Design

Fiberglass ducts integrate ductwork, insulation, and sound absorption functions into the same structural system, reducing the complexity of multi-material layering construction in traditional systems.

2. System Stability Brought by Structural Coordination

The structural layers do not exist independently, but rather form a synergistic relationship during actual operation, ensuring relative stability in airtightness, thermal performance, and acoustic performance of the duct.

VI. Differences Between Fiberglass Duct Structure and Traditional Metal Ducts

Compared to traditional galvanized steel ducts, fiberglass ducts emphasize material compositeness in their structural design:

Metal ducts are primarily formed from a single material.

Fiberglass ducts achieve a balance of comprehensive performance through a multi-layered structure.

This structural difference also determines the different focuses in application scenarios and system configurations.

VII. Impact of Structural Composition on Engineering Applications

Based on its structural characteristics, fiberglass ducts have high adaptability in the following scenarios:

Building ventilation systems with comprehensive requirements for insulation and sound attenuation

Air conditioning supply and return air systems in commercial and public buildings

Projects requiring high construction efficiency and system integration

From a structural composition perspective, fiberglass ducts are a typical multi-layered composite ventilation duct material. Its inner lining, fiberglass insulation and sound-absorbing layer, and outer protective structure together form a complete system, enabling the duct to achieve a relatively balanced performance in ventilation, insulation, and noise reduction. A thorough understanding of the structural composition of fiberglass ducts helps in making more rational judgments in the design and selection of HVAC systems.