Smart Vent sizing

How to measure your vents.

Vents come in many sizes and can vary from room to room. Measure each supply vent before you order, so every Smart Vent fits. All you need is a tape measure or your phone, and it only takes a few minutes.

SEE HOW TO MEASURE  → Shop Smart Vents ›

Smart Vents replace floor, wall and ceiling vents.

Three ways to measure

Pick the method that works for you.

Use any of these methods for each supply vent. In Canada, only the duct opening method works.

  1. Drawing of a vent cover with arrows across its outside width and height.

    1Fastest

    Outside dimensions

    Measure the outside of the vent cover and round down to the nearest even inch.

  2. Drawing of a vent cover lifted off its duct, with arrows across the width and height of the opening underneath.

    2Most accurate

    Duct opening

    Remove the vent cover and measure the duct opening directly.

  3. A phone measuring app icon with a ruler and a dotted line between two points.

    3Use a measuring app

    Out of reach?

    Use your phone's AR measuring app: Apple Measure (iOS) or AR Ruler (Android). Aim at the vent and read the dimensions on screen.

Measuring the duct opening.

  1. Remove your vent cover. Lift floor vents straight out. Wall and ceiling vents are held in with screws.
  2. Measure the width and height of the duct opening. Measure the inside of the opening, not the cover.
  3. Write down the size for each room. Then repeat for every supply vent you want to replace.

Keeping track of a lot of rooms? The Zoning worksheet has space for each room's vent sizes, one page per floor.
Download the worksheet (PDF) ›

An open floor duct with the vent cover removed, measured at 10 inches wide and 4 inches high across the opening.

Smart Vent sizes

Match your vents to a Smart Vent size.

Smart Vents come in these sizes, in inches.

  • 4 by 10 inches
  • 4 by 12 inches
  • 4 by 14 inches
  • 6 by 10 inches
  • 6 by 12 inches
  • 6 by 14 inches
  • 8 by 8 inches
  • 8 by 10 inches
  • 10 by 10 inches
  • 12 by 12 inches
No tape measure handy?

Start your plan now and measure later.

In the System Builder, pick Measure later for any vent. The builder saves your plan, so you can come back and add sizes when you're ready. You'll need a size for every vent before you order.

START BUILDING  → Not sure about a size? Chat with us ›

FAQ

Questions about measuring your vents.

How do I measure my vents for Flair Smart Vents?
Measure each supply vent, since sizes vary from room to room. For the fastest result, measure the outside of the vent and round down to the nearest even inch. For the most accurate result, remove the vent and measure the duct opening. In Canada, only the duct opening method works.
What sizes do Flair Smart Vents come in?
Smart Vents come in 4x10, 4x12, 4x14, 6x10, 6x12, 6x14, 8x8, 8x10, 10x10 and 12x12 inches.
Do Smart Vents work in floor, wall and ceiling vents?
Yes. Smart Vents replace wall, ceiling and floor vents. Measure them all the same way.
How do I measure a vent I can't reach?
Use your phone's AR measuring app, like Apple Measure on iOS or AR Ruler on Android. Aim at the vent and read the dimensions on screen.
Can I order Smart Vents before I measure?
No. Every Smart Vent needs a size before you can order. You can start your plan in the System Builder now and pick Measure later for any vent. The builder saves your plan, so you can come back and add sizes when you're ready.
What if my vent doesn't match a Smart Vent size?
Measure the duct opening again, since it's the most accurate method. If it still doesn't match one of our sizes, a Smart Vent won't fit that vent yet. We're expanding our size range, so check back soon, or sign up for our emails at the bottom of this page to hear when new sizes are released.
How do I install Smart Vents once I've measured?
Take out your old vent, then drop in and secure a new Flair Smart Vent. Our installation guide walks you through every step.

Next step

Got your sizes? Build your system.

Answer a few questions about your home, and you'll see what to buy and why.

START BUILDING  → See how to install Smart Vents ›