Measuring Air Velocity using Testo 410i

Bryan with HVAC School measures air velocity using Testo 410i from the new expanded Testo Smart Probes Case. We show how to use the volume flow outlet app in the Testo smart probes app to calculate air velocity and air volume flow.

In general, we'll want to see residential HVAC equipment with air velocities between 300 and 700 feet per minute (depending on the outlet type and location). You can use the Testo Smart Probes app to set up a timed average duct traverse. After you type in the specs of the equipment you're measuring, you can run the clock and hold the Testo 410i up to the vent you're measuring from.

In this case, we ran a test for 46 seconds and stopped the test. The 410i picked up 106 CFM and 193 feet per minute (we intentionally kept the velocity that low for noise reduction purposes and had oversized ducts).

[mattpierce]

On a smaller supply register, grill off...would you suggest timed average over multi point? Thanks!

[joeshearer]

What say you about traversing a return grille? Jim says don't use ak for that but I get really high numbers without factoring ak on returns with my 410.

[kcomfortsystemshvac]

Nice video, , , , I am not familiar air velocity, , if you the sistem has 2.000 CFM, ,,AIR HANDLER UNIT, , whit 6 register, ,,how many CFM evry register I should get ? Return air grill what should be reading, ,,? Can you help me that please, , , , thx