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Double Wall Rectangular Duct
The Double Wall Rectangular Duct is designed for HVAC systems that require both thermal insulation and sound attenuation. It consists of two layers of galvanized steel with an insulation layer—typically glass wool or rock wool—sandwiched between them.
This dual-wall design prevents heat loss, minimizes noise transmission, and eliminates condensation, ensuring efficient and quiet airflow for commercial and industrial buildings. Key Specifications
Material: Inner & outer galvanized steel sheets
Insulation: Glass wool or rock wool (25–50 mm)
Sheet Thickness: 0.5–1.2 mm per layer
Standard: SMACNA / DW144 / ISO 9001
Connection Type: TDC, TDF, Flange, or Slip Joint
Key Features
Thermal and Acoustic Performance
The double wall structure significantly reduces energy loss and sound transmission, maintaining a stable air temperature throughout the duct network.
Durable Construction
Both inner and outer layers are fabricated from galvanized steel, providing strength, rigidity, and resistance to corrosion over long-term operation.
Energy Efficiency
By minimizing temperature variation and air leakage, double wall ducts enhance HVAC system performance and reduce operational energy costs.
Custom Configurations
Available in various dimensions, insulation thicknesses, and connection systems to match project-specific designs and space constraints.
Technical Specifications
| Inner Wall | Galvanized steel (G90 / DX51D+Z) |
|---|---|
| Outer Wall | Galvanized steel (G90 / DX51D+Z) |
| Insulation | Glass wool / rock wool / foam board |
| Insulation Thickness | 25–50 mm (optional) |
| Sheet Thickness | 0.5–1.2 mm (per layer) |
| Connection Type | TDC / TDF / Flange / Slip Joint |
| Standard Length | 1000–1500 mm per section |
| Leakage Class | SMACNA Class 3 or higher |
| Standards | SMACNA / DW144 / ISO 9001 |
Applications
Double wall rectangular ducts are suitable for environments requiring temperature stability and sound control, including:
Material & Manufacturing Process
Each duct is fabricated using precision CNC cutting and automatic folding machines. The insulation material is evenly distributed between the two metal layers and sealed to prevent fiber shedding or air leakage.
Installation & Connection Methods
Double wall ducts are designed to integrate seamlessly with standard rectangular duct connection systems.
Depending on the project size and insulation thickness, the following connection types are used:
Depending on the project size and insulation thickness, the following connection types are used:
