Specifications
- Width: 2" to 48"
- Height: 2" to 48"
- Offset Distance: 2" to 24"
- Length: 6" to 36"
- Materials: Galvanized Steel, Aluminum, Stainless Steel
- Gauges: 26, 24, 22, 20
- Connections: Raw, Slip, Drive, TDC, Flanged
Standard Duct Offset Sizes & Pricing
| Width | Height | Offset | Length | Material | Gauge | Joints | Price | Order |
|---|---|---|---|---|---|---|---|---|
| 8" | 8" | 12" | Galvanized | 26 ga | Slip / Slip | $57.80 | ||
| 10" | 8" | 12" | Galvanized | 26 ga | Slip / Slip | $62.40 | ||
| 10" | 8" | 18" | Galvanized | 26 ga | Drive / Drive | $85.10 | ||
| 12" | 8" | 12" | Galvanized | 26 ga | Drive / Drive | $69.00 | ||
| 12" | 8" | 18" | Galvanized | 26 ga | Drive / Drive | $92.00 | ||
| 12" | 10" | 14" | Galvanized | 26 ga | Drive / Drive | $82.03 | ||
| 14" | 8" | 14" | Galvanized | 26 ga | Drive / Drive | $82.03 | ||
| 14" | 10" | 14" | Galvanized | 26 ga | TDC / TDC | $91.40 | ||
| 14" | 12" | 18" | Galvanized | 24 ga | TDC / TDC | $140.64 | ||
| 16" | 10" | 14" | Galvanized | 24 ga | TDC / TDC | $116.72 | ||
| 16" | 12" | 18" | Galvanized | 24 ga | TDC / TDC | $148.92 | ||
| 18" | 12" | 18" | Galvanized | 24 ga | TDC / TDC | $157.20 | ||
| 18" | 14" | 18" | Galvanized | 22 ga | TDC / TDC | $207.60 | ||
| 20" | 12" | 18" | Galvanized | 22 ga | TDC / TDC | $207.60 | ||
| 20" | 14" | 24" | Galvanized | 22 ga | Flanged / Flanged | $284.60 | ||
| 24" | 12" | 18" | Galvanized | 22 ga | Flanged / Flanged | $236.30 | ||
| 24" | 18" | 24" | Galvanized | 22 ga | Flanged / Flanged | $339.80 | ||
| 24" | 24" | 24" | Galvanized | 20 ga | Flanged / Flanged | $503.60 | ||
| 30" | 18" | 24" | Galvanized | 20 ga | Flanged / Flanged | $503.60 | ||
| 36" | 24" | 30" | Galvanized | 20 ga | Flanged / Flanged | $752.00 | ||
| 12" | 10" | 18" | Aluminum | 26 ga | Slip / Slip | $149.08 |
Custom Duct Offset Fittings — S-Shaped Obstruction Routing
Duct offsets are S-shaped fittings that shift the duct centerline vertically or horizontally while maintaining the same cross-section size. They consist of two opposing bends connected by a straight section, creating a smooth parallel displacement of the duct run. Offsets are essential for routing ductwork around structural beams, plumbing stacks, electrical conduit, and other obstructions without changing duct size.
Offset Distance vs. Length
The offset distance is the perpendicular displacement between the inlet and outlet centerlines. The fitting length determines the taper angle of the two bends. A longer length produces a more gradual S-curve with lower pressure drop and less turbulence. As a rule, the length should be at least 2.5 times the offset distance for good airflow. A 6" offset should use at least a 15" fitting length.
Common Obstruction Scenarios
Residential systems most often need offsets to route trunk lines around steel I-beams (typically 4-6" offset), plumbing stacks (3-4" offset), or to shift duct position between floor joists. Commercial systems encounter larger obstructions from structural steel, fire sprinkler mains, and electrical busway. Our custom offset distances from 2" to 24" handle virtually any field condition.
Single-Piece vs. Two-Elbow Construction
Field-fabricated offsets are typically made by connecting two separate elbows, creating two joints that leak and add material cost. Our offsets are fabricated as a single piece with no intermediate joints, providing a tighter seal, cleaner appearance, and easier installation. The single-piece construction also improves airflow by eliminating the discontinuity at the elbow junction.
Frequently Asked Questions
How is offset distance calculated?
The offset distance is the perpendicular displacement between the inlet and outlet centerlines. Specify this dimension directly in the designer.
Can I adjust the angle of the offset?
Offset angle is determined by the offset distance and the fitting length. A longer fitting produces a more gradual angle with lower pressure drop.