In ventilation and air conditioning engineering, duct systems not only serve the function of supplying and returning air but also directly affect system energy efficiency, noise levels, and operational reliability. Fiberglass ducts, as a type of duct integrating insulation and sound absorption, are widely used in engineering projects; however, their performance is highly dependent on the appropriateness of the initial selection. The following is a systematic analysis of the key points for selecting fiberglass ducts from the perspective of engineering design and implementation.

First, it is necessary to clarify the system pressure rating and airflow requirements. Fiberglass ducts are more suitable for low- and medium-pressure ventilation and air conditioning systems. Their structural strength and interface type determine that they should not be blindly used in high-pressure, high-airflow systems. During the selection phase, a comprehensive judgment should be made based on the design wind speed, static pressure rating, and duct diameter to ensure that the pressure-bearing capacity of the fiberglass duct matches the system operating conditions.

Second, fire resistance and compliance with regulations are key factors in the selection process. Fiberglass ducts use inorganic glass fiber as the main material, and the duct itself has good fire resistance. However, different products vary in terms of cladding materials, fire ratings, and testing standards. When selecting ductwork for a project, it is essential to verify whether the product meets the fire safety requirements for duct systems, especially in public buildings, high-rise buildings, and densely populated areas.

Third, the matching of insulation performance and design thickness should be a key consideration. Fiberglass ducts are inherently insulated, and their thickness and density directly affect thermal conductivity and system efficiency. Selection should consider supply air temperature, ambient temperature and humidity, and anti-condensation requirements to determine the appropriate duct thickness and avoid condensation risks due to insufficient thickness.

Fourth, sealing performance and interface type significantly impact system efficiency. Air leakage in fiberglass ducts primarily occurs at the interfaces, and different connection methods offer varying sealing reliability. When selecting ductwork for a project, priority should be given to products with mature interfaces and well-developed sealing systems. The contractor's familiarity with the system should also be considered to minimize leakage risks caused by construction deviations.

Fifth, the internal wall structure and airflow quality requirements are also factors to consider during selection. The inner wall of fiberglass ducts is typically made of fiberglass fabric or a cladding structure, which has a certain sound absorption effect, helping to reduce system noise. However, in environments with high cleanliness requirements, such as hospitals, laboratories, or cleanrooms, it is crucial to assess whether the internal wall structure meets hygiene and cleanliness requirements, and select an appropriate lining type if necessary.

Sixth, construction conditions and site suitability directly affect the application effect of fiberglass ducts. Fiberglass ducts are mostly fabricated on-site, placing certain requirements on the construction environment, processing precision, and installation conditions. When selecting a type, the project schedule, construction space, and the experience of the construction team should be considered to assess its on-site feasibility.

Finally, economic efficiency and total life-cycle cost should not be overlooked. Fiberglass ducts offer integrated advantages in materials, insulation, and sound absorption, reducing the overall cost of traditional metal ducts with insulation. However, if used in unsuitable conditions, later maintenance and modification costs may increase. Therefore, selection should be comprehensively evaluated from the perspective of overall system cost and long-term operation.

In summary, the core of fiberglass duct project selection lies in "operating condition matching." Provided that the system pressure, fire protection requirements, insulation and anti-condensation needs, and construction conditions are all suitable, fiberglass ducts can fully demonstrate their advantages in energy saving, noise reduction, and integration; conversely, if the selection is not in line with the actual working conditions, its performance advantages will be difficult to realize.