Specifications
- A Width: 1" to 36"
- A Thickness: 1" to 36"
- B Width: 1" to 36"
- B Thickness: 1" to 36"
- Throat Width: 1" to 36"
- Materials: Galvanized Steel
- Connections: Raw, Slip, Drive, FoldOut, DoubleFoldOut
Standard Duct Elbow Sizes & Pricing
| A Width | A Thick | B Width | B Thick | Throat | A Joint | B Joint | Price | Order |
|---|---|---|---|---|---|---|---|---|
| 6" | 6" | 6" | 6" | 3" | Raw | Raw | $12.40 | |
| 8" | 6" | 8" | 6" | 4" | Raw | Raw | $14.80 | |
| 8" | 8" | 8" | 8" | 4" | Slip | Slip | $18.60 | |
| 10" | 6" | 10" | 6" | 4" | Raw | Raw | $16.20 | |
| 10" | 8" | 10" | 8" | 4" | Slip | Slip | $20.40 | |
| 10" | 10" | 10" | 10" | 5" | Slip | Slip | $24.80 | |
| 12" | 8" | 12" | 8" | 4" | Slip | Slip | $22.50 | |
| 12" | 10" | 12" | 10" | 5" | Drive | Drive | $28.70 | |
| 12" | 12" | 12" | 12" | 6" | Drive | Drive | $32.40 | |
| 14" | 8" | 14" | 8" | 4" | Slip | Slip | $25.60 | |
| 14" | 10" | 14" | 10" | 5" | Drive | Drive | $30.80 | |
| 14" | 12" | 14" | 12" | 6" | Drive | Drive | $35.20 | |
| 16" | 10" | 16" | 10" | 5" | Drive | Drive | $34.60 | |
| 16" | 12" | 16" | 12" | 6" | FoldOut | FoldOut | $42.30 | |
| 18" | 12" | 18" | 12" | 6" | FoldOut | FoldOut | $48.50 | |
| 20" | 12" | 20" | 12" | 6" | FoldOut | FoldOut | $54.80 | |
| 20" | 14" | 20" | 14" | 8" | DoubleFoldOut | DoubleFoldOut | $68.40 | |
| 24" | 12" | 24" | 12" | 6" | FoldOut | FoldOut | $62.50 | |
| 24" | 18" | 24" | 18" | 8" | DoubleFoldOut | DoubleFoldOut | $88.20 | |
| 24" | 24" | 24" | 24" | 10" | DoubleFoldOut | DoubleFoldOut | $112.60 | |
| 30" | 18" | 30" | 18" | 10" | DoubleFoldOut | DoubleFoldOut | $128.40 | |
| 36" | 18" | 36" | 18" | 10" | DoubleFoldOut | DoubleFoldOut | $148.50 | |
| 36" | 24" | 36" | 24" | 12" | DoubleFoldOut | DoubleFoldOut | $165.00 |
Custom 90° Duct Elbows — Precision Fabricated Turns
Duct elbows are essential fittings that redirect airflow around corners, obstructions, and structural elements. Our 90-degree elbows feature independent A-side and B-side dimensioning, allowing for equal or unequal leg sizes. The throat width controls the turn radius—larger throat dimensions produce a more gradual turn with lower pressure drop and reduced turbulence.
Joint Types for Duct Elbows
Unlike straight duct that uses standard slip or TDC connections, elbows use specialized joint types. Raw edges are left unfinished for field attachment. Slip joints allow one end to slide inside the connecting duct. Drive connections use drive cleats for quick assembly. FoldOut and DoubleFoldOut joints create a flanged edge for rigid bolted connections on larger elbows.
Sizing for Optimal Airflow
The throat width is the most critical dimension for an elbow’s aerodynamic performance. ASHRAE guidelines recommend a throat-to-width ratio of at least 0.5 for acceptable pressure loss. For low-noise installations in occupied spaces, a ratio of 0.75 or higher is recommended. Internal turning vanes can further reduce pressure drop by 50% or more.
Residential vs. Commercial Elbows
Residential elbows typically range from 6"×6" to 14"×12" with raw or slip joints in 26 gauge galvanized steel. Commercial elbows use 16" and larger dimensions with drive, foldout, or double-foldout joints for structural rigidity. All elbows are fabricated from precision-cut cheeks and a formed throat piece for consistent geometry.
Frequently Asked Questions
What throat width should I use for a duct elbow?
ASHRAE recommends a throat-to-width ratio of at least 0.5. For low-noise installations, use a ratio of 0.75 or higher. A larger throat produces a more gradual turn with lower pressure drop.
Can the A-side and B-side be different sizes?
Yes. Our elbows have fully independent A-side and B-side dimensions, allowing for equal or unequal leg sizes to match your duct layout.
What joint types are available for elbows?
Raw, Slip, Drive, FoldOut, and DoubleFoldOut. Each side can have a different joint type. Residential typically uses Raw or Slip; commercial uses Drive, FoldOut, or DoubleFoldOut.