Performance Analysis, Installation Guide and Maintenance Tips for Sheet Metal Air Ducts

 

As the core component of building ventilation systems, sheet metal air ducts are widely used in the ventilation, air - conditioning and smoke exhaust systems of residential, commercial and industrial buildings due to their durability and economy. This article will comprehensively analyze the functions and usage skills of sheet metal air ducts from aspects such as material characteristics, application scenarios, installation specifications and maintenance points.

 

I. Materials and Performance Characteristics of Sheet Metal Air Ducts

Sheet metal air ducts are usually made of galvanized steel sheets or stainless steel, with the following characteristics:

1.Corrosion resistance: The galvanized layer can effectively prevent the sheet metal from oxidizing and rusting, thus extending its service life [1].

2.High structural strength: The metal material endows the air duct with good pressure - bearing capacity, making it suitable for medium - and high - pressure ventilation systems.

3.High - temperature resistance: Sheet metal air ducts can withstand relatively high temperatures and are often used in smoke exhaust systems or high - temperature industrial environments [3].

 

Comparison with air ducts made of other materials:

-Fabric air ducts: They are light in weight and have a low air leakage rate, but their high - temperature resistance and structural strength are weaker than those of sheet metal air ducts. They are mostly used for light - load air - conditioning air supply.

-Composite material air ducts: Made of materials such as fiberglass or polyurethane, they have excellent thermal insulation performance but are relatively high in cost. They are suitable for occasions with strict energy - saving requirements.

 

II. Application Fields of Sheet Metal Air Ducts

1.Ventilation systems: Used to transport fresh air or exhaust indoor waste gas, commonly seen in places such as shopping malls and office buildings.

2.Air - conditioning systems: Used in conjunction with thermal insulation layers, they can transport cold and hot air to ensure a balanced indoor temperature.

3.Smoke exhaust systems: Quickly exhaust smoke in case of fire, improving the fire - fighting safety of buildings [3].

 

III. Installation Specifications for Sheet Metal Air Ducts

Correct installation is the key to ensuring the performance of air ducts, and the following steps need to be followed:

1.Positioning of supports and hangers:

   - The spacing between supports and hangers needs to be designed according to the size and weight of the air duct. Generally, it should not exceed 3 meters for horizontal installation and 4 meters for vertical installation.

   - The suspension rods should be kept vertical to avoid deformation caused by uneven stress.

2.Air duct connection process:

   - The threading direction of flange bolts should be consistent with the air flow direction to prevent the bolts from loosening.

   - Sealing glue or tape should be used to seal the joints tightly to ensure that the air leakage rate is lower than 5% [5].

3.Treatment in special environments:

   - Double - layer galvanized steel sheets or additional fire - proof and heat - insulating layers should be used for high - temperature smoke exhaust air ducts.

   - In a humid environment, it is recommended to use stainless steel to avoid the corrosion and peeling of the galvanized layer.

 

IV. Usage and Maintenance Recommendations

1.Regular inspection:

   - Check the air duct surface for rust and the joints for cracks every quarter, and repair the damaged parts in time.

   - Test the air leakage rate of the system to ensure that the ventilation efficiency meets the design requirements.

2.Cleaning and maintenance:

   - Use a soft brush or a vacuum cleaner to remove the dust inside the air duct to prevent the breeding of bacteria.

   - Avoid using acidic cleaning agents to prevent corrosion of the galvanized layer.

3.Anticorrosion treatment:

   - If local corrosion is found, spray anti - rust paint or zinc - based paint after sanding.

   - For air ducts exposed to a humid environment for a long time, it is recommended to add a moisture - proof layer.

 

V. Advantages and Limitations of Sheet Metal Air Ducts

Advantages:

-Low cost: The material and processing costs are lower than those of stainless steel or composite material air ducts.

-Flexible installation: It can adapt to complex building structures through cutting and bending.

 

Limitations:

-Heavy weight: It requires strengthening of the support structure, increasing the construction difficulty.

-High noise: Resonance is likely to occur when high - speed airflow passes through, and a noise - reduction device needs to be added.

 

VI. Precautions for Selection and Procurement

1.Material selection:

   - Select galvanized steel sheets (with a thickness of 0.5 - 1.2 mm) in ordinary environments, and stainless steel is preferred in corrosive environments.

   - Select the plate grade according to the national standard GB/T 15329 to ensure that the thickness error is within ±0.01 mm [2].

2.Supplier evaluation:

   - Choose manufacturers with automated processing equipment (such as CNC shearing machines and bending machines) to ensure the dimensional accuracy of the air ducts [5].

   - Request the provision of material inspection reports and fire - performance certifications.

 

Through reasonable selection, standardized installation and regular maintenance, sheet metal air ducts can serve various ventilation systems stably for a long time. For high - humidity or highly corrosive scenarios, it is recommended to customize anti - corrosion solutions according to the usage environment to maximize the service life of the equipment.