20" x 8" x 48" Straight Rectangular Duct — $99.76
- Width: 20"
- Depth: 8"
- Length: 48"
- Gauge: 22 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 20" wide x 8" deep straight rectangular duct, 48" long, in 22-gauge galvanized steel with slip-and-drive connections on both ends. Pittsburgh-locked seam, made to order in Pittsburgh.
20" x 8" x 48" Straight Rectangular Duct: sizing numbers
Worked out from this size's dimensions, so you can check it against your duct design before you order.
| Free area | 1.11 sq ft (160 sq in) |
| Perimeter | 56" |
| Equivalent round duct (equal friction) | 13.5" diameter |
| Equal-area round duct | 14.3" diameter |
| Aspect ratio | 2.5 : 1 |
| Sheet metal in the walls | about 18.7 sq ft |
| Approximate sheet weight | about 26 lb (22-gauge galvanized at 1.406 lb per sq ft, before seams and connectors) |
Airflow by velocity
| Air velocity | Duct (1.11 sq ft) |
|---|---|
| 600 fpm | 665 CFM |
| 700 fpm | 780 CFM |
| 900 fpm | 1,000 CFM |
| 1,200 fpm | 1,335 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
How many CFM does a 20" x 8" rectangular duct carry?
About 780 CFM at 700 fpm and 1,000 CFM at 900 fpm. A 20" x 8" duct has 1.11 sq ft of free area, and airflow is free area times air velocity, so multiply 1.11 by the velocity your design calls for.
What round duct is equivalent to a 20" x 8" rectangular duct?
About 13.5" round. That is the equal-friction equivalent diameter, 1.30 x (a x b)^0.625 / (a + b)^0.25, the round size that carries the same airflow at the same friction loss. The round duct with the same free area (1.11 sq ft) is 14.3".
What gauge is a 20" x 8" rectangular duct made in?
22-gauge galvanized steel. PMX picks the gauge from the distance around the largest opening: a 20" x 8" duct is 56" around, and openings that measure over 54" up to 84" around are built in 22 gauge. The configurator on this page lets you choose 26, 24, 22 or 20 gauge and re-prices it.
How much does a 20" x 8" rectangular duct cost?
$99.76 as configured on this page: 22-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 $156.63 in aluminum and $213.51 in stainless steel. In galvanized steel, the 60" long version is $118.84.
Can I order a straight duct 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 20" x 8" rectangular duct 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 20" x 8" x 48" Straight Rectangular Duct configuration of our straight rectangular duct. 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.