12" x 8" Duct Offset, 4" Shift, 18" Long — $76.69
- Size: 12" x 8"
- Offset: 4"
- Length: 18"
- Gauge: 24 ga
- Material: Galvanized Steel
- Connections: Slip & drive
- Fabrication: Made to order in Pittsburgh, PA
- Lead time: Ships in 1 business day
- Returns: Made to order, not returnable
Custom fabricated 12" x 8" S-offset duct with a 4" lateral shift over 18", 24-gauge galvanized steel, slip-and-drive both ends. Made to order.
12" x 8" Duct Offset, 4" Shift, 18" Long: sizing numbers
Worked out from this size's dimensions, so you can check it against your duct design before you order.
| Lateral shift | 4" |
| Body length | 18" |
| Average slope of the body | about 13 degrees off the run (4 in 18) |
| Free area | 0.67 sq ft (96 sq in) |
| Perimeter | 40" |
| Equivalent round duct (equal friction) | 10.7" diameter |
| Equal-area round duct | 11.1" diameter |
| Aspect ratio | 1.5 : 1 |
Airflow by velocity
| Air velocity | Duct (0.67 sq ft) |
|---|---|
| 600 fpm | 400 CFM |
| 700 fpm | 465 CFM |
| 900 fpm | 600 CFM |
| 1,200 fpm | 800 CFM |
Airflow is free area times air velocity. Pick the row that matches the velocity your design uses; these figures are capacity at that velocity, not a pressure-loss calculation.
Questions about this size
What angle is a 4" offset over 18"?
About 13 degrees off the line of the duct, averaged over the body: the centreline moves sideways 4" while it travels 18". A longer body lowers that angle and the pressure loss with it; a shorter one fits a tighter space.
How many CFM does a 12" x 8" duct offset with a 4" shift carry?
About 465 CFM at 700 fpm and 600 CFM at 900 fpm. The 12" x 8" duct has 0.67 sq ft of free area, and airflow is free area times air velocity, so multiply 0.67 by the velocity your design calls for.
What gauge is a 12" x 8" duct offset with a 4" shift made in?
24-gauge galvanized steel. PMX picks the gauge from the distance around the largest opening: a 12" x 8" duct is 40" around, and openings that measure over 30" up to 54" around are built in 24 gauge. The configurator on this page lets you choose 26, 24, 22 or 20 gauge and re-prices it.
How much does a 12" x 8" duct offset with a 4" shift cost?
$76.69 as configured on this page: 24-gauge galvanized steel, made to order. The price comes from the same quoting engine that prices the cart, and changing any dimension in the configurator re-prices it. The same size is $115.69 in aluminum and $154.69 in stainless steel.
Can I order a duct offset in a different size?
Yes. This page is one published size; the configurator above is loaded with these dimensions and every one of them can be changed to the size you measured, in galvanized steel, aluminum or stainless steel. Each fitting is cut and formed for the order in Pittsburgh, PA.
How fast does a 12" x 8" duct offset with a 4" shift ship, and can it be returned?
It ships in 1 business day from our Pittsburgh, PA shop, by UPS or by LTL freight for large orders, anywhere in the continental US. Shipping is calculated at checkout from the order's weight and destination. Because it is made to the dimensions you order, it is not returnable.
About this size
This page is the 12" x 8" Duct Offset, 4" Shift, 18" Long configuration of our duct offset. It is cut and formed for this order — nothing here is a stock import part. The configurator above is loaded with these exact dimensions, so you can add it to the cart as-is, or change a dimension and it re-prices instantly.