6x14 Metal Floor Vents: Free Area, Airflow and Duct Fit
A 6x14 floor vent has a free area of 19.4 square inches and a calculated airflow of 68 CFM, and it drops into a duct opening of 148.9 x 351.9 mm.
- Duct opening
- 5.86″ × 13.85″
- Metric
- 148.9 × 351.9 mm
- Best free area
- 19.4 sq in
- Comes in
- Undermount
6x14 is the largest floor vent Khan Supply makes and the highest free area in the floor line at 19.4 square inches.
Free area and airflow at this size
| Product | Free area | Open | Airflow | Price | |
|---|---|---|---|---|---|
| Undermount Flush Floor Vent [Metal] | 19.4 sq in | 23% | ≈ 68 CFM | from $114.99 | View 6x14 |
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
6x14 is Undermount only and needs a 148.9 mm by 351.9 mm opening, the largest floor cut we specify, so confirm there is no joist or strapping run crossing the line before you commit to it.
Is the 6x14 worth the step up from the 6x12?
It buys about 11 percent: 19.4 square inches of free area against 17.4, or 68 calculated CFM against 61. That is the largest floor figure we publish. Whether you feel it depends on the branch duct, so treat the step up as a sizing and appearance decision first.
Why does percent open keep falling as the vent gets bigger?
Because the numerator and the denominator grow at different rates. Free area is the ring around the inner tray, which scales with perimeter. Percent open divides that by the nominal face, which scales with area. The 6x14 has the most free area of any floor vent we make, 19.4 square inches, and the lowest percentage, 23 percent, for that reason.
Does the 6x14 come in a 5-pack?
Yes. The Undermount Flush Floor Vent is sold as a single and as a 5-pack in every size including 6x14. Shipping is free either way, so there is no freight penalty for buying singles when you are matching an odd count of openings.
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