How To Measure Floor Vent Size

Pull the vent forward and out of the opening.

How to measure floor vent size. How to measure and replace a floor register. Many of our vent grilles include directional patterns so it is crucial to provide both dimensions in their respective order. A register is measured by the size of its louvers which is the bottom of the register that fits into the ventilation duct. For floor registers they follow the same rules as return grilles where you state the dimension parallel to the louvers first.

The length l is always expressed first followed by the height h dimension. Remove the screws that hold the vent in place. Take out the existing floor register and measure the length width of the opening in inches all registers will be listed in inches. This means that floor registers will often be smaller number first like 4 10 or 4 12.

You could also use a 4 x10 floor register if your hole measured 4 1 4 x 10 1 2. Remove screws holding the vent in place. Measure the opening in your floor wall or ceiling. Locate the register or grille you are replacing and note if it is for a wall ceiling or floor.

If your hole measures 3 7 8 x 9 7 8 you should be able to use a 4 x 10 floor register depending on the style. However the overall size of the opening must be considered. The width and length of your opening should match the duct opening sizes. For example a 4 x 10 flush mount wood register has an overall size of 6 x 12.

To measure your register properly remove the existing register from the floor wall or ceiling in which it is installed. For sizing please use the duct size and reference the overall frame size for installation. Most vent faceplates are large enough to support the register and cover the entire hole. Note if the register or grille you are replacing is for a wall ceiling or floor.

Then measure the length and width of the air duct opening. If your duct work opening in the floor is 4 x 10 you ll need to purchase a 4 10 floor register. Length in inches by height in inches this is your duct opening size.