In modern buildings, fiberglass ducts are widely used in HVAC systems due to their lightweight, high-temperature resistance, and excellent thermal and sound insulation properties. As a highly efficient ventilation duct solution, fiberglass ducts can effectively reduce energy loss, noise pollution, and improve the overall efficiency of the system. However, with increased use, the performance of fiberglass ducts may degrade, thus affecting the system's operating efficiency and lifespan. This article will analyze the main factors affecting the performance degradation of fiberglass ducts from multiple perspectives and explore how to extend their service life.

I. Temperature Changes

The thermal insulation performance of fiberglass ducts is prone to degradation under extreme temperatures. Long-term exposure to high or low temperatures, especially under conditions of large temperature differences, may cause changes in the fiber structure of the fiberglass duct, leading to an increase in thermal conductivity and thus reducing the insulation effect. The performance degradation of fiberglass ducts is particularly pronounced in areas with large temperature differences between summer and winter.

High-Temperature Environments: Prolonged exposure to high temperatures may cause the surface coating of fiberglass ducts to age or peel off, gradually weakening the insulation effect.

Low Temperature Environment: At low temperatures, the fiberglass duct material may shrink, leading to structural instability in the insulation layer and affecting its insulation performance.

II. Humidity and Moisture Permeation

Fiberglass ducts contain numerous air pores, which effectively insulate but also easily absorb moisture. If exposed to high humidity, moisture may seep into the duct, reducing its internal insulation performance. Moisture resistance is particularly important in air conditioning ducts and refrigeration facilities.

Moisture Permeation: When moisture seeps into the duct, the fiber structure may expand or deform, affecting the integrity of the insulation layer and ultimately increasing heat loss.

Condensation: In humid environments, condensation easily forms on fiberglass ducts. This not only reduces insulation effectiveness but may also cause mold and corrosion, further accelerating material aging.

III. Physical Damage and Mechanical Stress

The performance degradation of fiberglass ducts is also related to physical damage during installation and use. Although fiberglass ducts possess inherent compressive and bending resistance, improper installation can lead to flattening, cracking, or other deformations. This physical damage affects the duct's structural integrity, resulting in decreased insulation performance.

Bending and Compression: Fiberglass ducts may be bent or compressed during installation or transportation, causing structural changes, creating thermal bridges, and affecting insulation effectiveness.

Vibration and Impact: During operation, fiberglass ducts may be subjected to vibration and impact. Long-term mechanical stress can lead to material fatigue, causing the insulation layer to gradually break down or detach.

IV. Ultraviolet Radiation

While the external protective layer of fiberglass ducts typically resists UV erosion, long-term exposure to sunlight can still affect them. UV radiation accelerates the aging of the outer layer, causing the surface coating to peel off and impacting overall protective performance. The effects of UV radiation are particularly significant in areas exposed outdoors or under high-intensity sunlight.

Surface Aging: Long-term UV exposure can cause the duct surface coating to lose its original strength, thus affecting its thermal insulation and fire resistance.

Strength Reduction: As the outer layer ages, the strength and durability of the duct may decrease, leading to the exposure of the internal insulation layer and affecting the system's thermal insulation performance.

V. Air Velocity and Duct Ventilation

The air velocity of the duct also has a certain impact on its internal structure and performance. In environments with high wind speeds and strong airflow, the internal insulation layer of the fiberglass duct may loosen or be damaged due to the airflow. Furthermore, changes in ventilation volume during long-term use can also affect the thermal insulation performance of the fiberglass duct. Larger airflow volumes and higher airflow velocities may lead to increased heat loss, especially under prolonged high-load operation.

High Airflow Velocity: High-speed airflow may cause excessively high internal temperatures in the duct, leading to aging and ablation of the insulation material.

Dust Accumulation in Ducts: Over time, dust may accumulate inside the duct, affecting airflow and insulation performance.

VI. Chemical Corrosion

Fiberglass duct materials are sometimes susceptible to corrosion from chemical substances, especially in highly chemical environments. Corrosion or chemical reactions may occur, damaging the insulation layer. For example, chemical gases and acids/alkalis in industrial plants can damage the outer protective coating of fiberglass ducts.

Corrosive Environments: In certain specialized industrial environments, fiberglass ducts may be corroded by chemical gases, causing the outer layer to lose its protective function and accelerating material aging.

VII. Recommendations for Extending the Service Life of Fiberglass Ducts

To effectively extend the service life of fiberglass ducts and reduce performance degradation, the following recommendations can help improve the overall efficiency of the duct system:

1. Appropriate Material and Thickness Selection: Select suitable fiberglass duct materials and thicknesses based on the actual operating environment to ensure the insulation performance of the duct system.

2. Enhanced Moisture-Proofing Design: During design and construction, the construction of a moisture-proof system should be emphasized to ensure that the ducts are not affected by high humidity environments.

3. Regular Maintenance and Inspection: Regularly inspect the duct system, especially joints and bends, to promptly identify and repair any problems.

4. Avoid High Temperatures and Strong UV Exposure: During installation, avoid prolonged exposure of the ducts to strong sunlight and excessive use in high-temperature environments.

5. Optimize Airflow and Cleanliness Management: Ensure smooth airflow within the ducts and regularly clean accumulated dust inside to reduce resistance and heat loss.

VIII. Conclusion

Fiberglass ducts, as an important building insulation material, experience performance degradation primarily due to factors such as temperature, humidity, physical damage, UV radiation, airflow velocity, and chemical corrosion. Through scientific design, standardized construction, and regular maintenance, the performance degradation of fiberglass ducts can be effectively slowed down, ensuring their continued high efficiency in building ventilation systems.