2x12 Metal Floor Vents: Free Area, Airflow and Duct Fit
A 2x12 floor vent has a free area of 13.4 square inches and a calculated airflow of 46 CFM, and it drops into a duct opening of 55 x 301.9 mm.
- Duct opening
- 2.17″ × 11.89″
- Metric
- 55 × 301.9 mm
- Best free area
- 13.4 sq in
- Comes in
- Undermount
2x12 is the narrowest floor size we build and the most open floor vent we publish at 50 percent, and only the Undermount is made in it.
Free area and airflow at this size
| Product | Free area | Open | Airflow | Price | |
|---|---|---|---|---|---|
| Undermount Flush Floor Vent [Metal] | 13.4 sq in | 50% | ≈ 46 CFM | from $54.99 | View 2x12 |
Free area is the open cross-section air actually passes through, not the outside of the cover. How we calculate it.
Measuring for this size
The part is built 2.25 by 12 rather than a true 2 by 12, so it drops into a duct opening of 55.0 mm by 301.9 mm. A duct cut to a strict 50.8 mm is about 4 mm too narrow to take it.
Will a 2x12 vent fit a duct that measures exactly 2 inches wide?
No. The 2x12 Undermount drops into a duct opening of 55.0 mm by 301.9 mm, which is 2.17 inches wide. A duct cut to a strict 50.8 mm is roughly 4 mm too narrow and the vent will not seat. Widen the opening to 55.0 mm before ordering. Do not step up to the 3x10, which needs 73.9 mm and is wider still.
Why is the 2x12 the most open floor vent you sell?
Because free area is the ring around the inner tray, and a narrow, long opening carries more perimeter for its face area than a wide one does. The 2x12 works out to 50 percent open, the highest percent-open figure on any Khan Supply floor vent, on a total free area of 13.4 square inches and 46 calculated CFM.
Where does a 2x12 floor vent usually go?
In a stair riser, a narrow hallway, or hard against a baseboard or a cabinet toe-kick where a 4-inch-wide register will not clear the trim. Its duct opening is 55.0 mm wide, so it needs far less floor cut open than any other size in the line.
How do I measure for a replacement vent?
Measure the duct opening, not the old cover. Pull the existing vent out, measure the hole itself across the width and the length in millimetres, and match that to the duct dimension listed on this page. Vent sizes are named for the duct, so a vent called 4x10 has a face larger than 4 by 10 inches. Measuring the faceplate is the single most common reason a size arrives wrong.
What happens if I order the wrong size?
Email support@khansupply.co with your order number and the millimetre measurements of your opening, and we will work out which size actually fits and sort out the exchange. Every Khan Supply vent also carries a 2-year warranty against defects, which is separate from a fit exchange.
What does shipping cost?
Nothing. Shipping is free on every order across North America, on a single vent and on a 5-pack alike. You will get tracking by email once the order is on its way. If a vent arrives damaged, photograph the box and the part and email support@khansupply.co, Monday to Friday 9 to 5 ET, and we reply within one business day.
Every Khan Supply vent is all metal, not plastic, and ships free across North America with a 2-year warranty. If a size is wrong, email support@khansupply.co and we sort out the exchange. Mon-Fri 9-5 ET, one business day reply.
Not sure of your size? · All sizes and free-area figures · Every size we make