A single point measurement can be used in round or rectangular duct, the accuracy is generally lower with a single-point measurement though. If higher accuracy is desired, a multi-point test using five test holes in rectangular and two test holes in round duct can be performed.
Whats funny is the 8.5 duct diameters thing, ive seen manometer manufacturers say anywhere between 8 and 13 ft downstream and 3 to 6 upstream from restrictions or changes in duct. In the real world, when is that ever even close to possible. I havnt found many if at all in my 27 years. So makes you wonder
Hi. Do you know a standalone instrument that can measure the pressure inside a hyperbaric chamber in ATA or psi. Is there a wrist worn unit that can do this. Thanks for your help.
Nice video! I have a potential problem with low airflow in a package unit that only has flexible ducting. What process would you recommend to measure either CFM or ESP in flex ducting? Thanks.
Unfortunately, it is very difficult to measure anything in flex. If you are looking for total system airflow use the digital TrueFlow grid or the static pressure tables for the equipment. If you are looking for supply or return airflow use a flow hood or large vane anemometer at the grilles.
Thanks, can you clarify one thing. If the static pressure is too high , the CFMs drop but the air velocity is increased ? So even though there is a cfm drop the velocity is increased and can cause noise issues?
You can’t use a testo 510 and pitot tube to measure residential airflow. The range of the 510 is not low enough and the resolution is not fine enough You may be confusing two things. Total External Static Pressure (TESP) in the system is the load against which the distribution fan has to "push" the air. Higher TESP usually means lower system airflow or excess energy use in an ECM motor. Measuring Static pressure drop OVER an A-coil or heat exchanger is an indirect method to determining air flow (CFM) via pressure drop over a component and brand and model specific manufacturer data. Excessive CFMs (airflow) through grilles and ductwork can produce excess noise If you have any additional questions, please do reach out by email at billy@trutechtools.com!
The key is choosing the correct manometer with sufficient accuracy for the flow velocity (total/velocity pressure). To measure under 3.5 m/s (700 feet per minute) you need a finer resolution manometer like the TSI AirPro 800 or the testo 512. The pitot tube can be the same, just the manometer changes.
Hey, Bryan, I was recently listening to one of your podcasts, and you were referring to a video you made with a pitot tube that you did incorrectly. Is this that video, or did you get rid of that one already? Thanks so much for all the content you put out. You guys are doing a great service.
This was the one. Bryan was using a digital manometer that did not have high enough accuracy for the relatively low flow pressures in a residential duct. Only when flow velocities are above 700 Feet Per Minute can a manometer of this type be used effectively with a Pitot tube.
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Jeez I needed this
Informative video. But I have a doubt. Why does spiral and round duct requires 2 wholes where rectangular ones need only one?
A single point measurement can be used in round or rectangular duct, the accuracy is generally lower with a single-point measurement though. If higher accuracy is desired, a multi-point test using five test holes in rectangular and two test holes in round duct can be performed.
i love the new videos....with Bryan Orr! hes the man!!!!
BK HVAC thanks man
Bryan Orr i mean it man! GREAT job
Thanks for sharing this too nice and informative video.
Glad it was helpful!
Whats funny is the 8.5 duct diameters thing, ive seen manometer manufacturers say anywhere between 8 and 13 ft downstream and 3 to 6 upstream from restrictions or changes in duct. In the real world, when is that ever even close to possible. I havnt found many if at all in my 27 years. So makes you wonder
HI, can we measure the flow velocity of a tube around 5 mm O.D. with pitot tube? Are pitot tubes available for such small diameters?
Helpful video, thank you
T&B humor - Happy Little Pitot Tube. Funny.
Happy little ducties 😂
Where can i get the static pressures probes.
That app for atmospheric pressure seems to be way off. 14.9 psi is unbelievably high even with a lot of pumped positive building pressure.
How do I measure CFM from a fan on an air handling unit that has a large ductwork? Think a larger AHU for hospitals, offices and so on?
Good video. Is that a special phone case with a magnet? If so, where did you get that? Thx
Will a dual port manometer with pressure switch tester read fcm's with pitot tubes? Good video. Thanks!
Hey Bryan, appreciation from India. keep going. can we use pitot tube for 0 to 2 hpa?
Yes, 2.49 hPa per inch of water. Maybe the app allows scale units to be changed to hPA.
Hi. Do you know a standalone instrument that can measure the pressure inside a hyperbaric chamber in ATA or psi. Is there a wrist worn unit that can do this. Thanks for your help.
Nice video! I have a potential problem with low airflow in a package unit that only has flexible ducting. What process would you recommend to measure either CFM or ESP in flex ducting? Thanks.
Unfortunately, it is very difficult to measure anything in flex. If you are looking for total system airflow use the digital TrueFlow grid or the static pressure tables for the equipment. If you are looking for supply or return airflow use a flow hood or large vane anemometer at the grilles.
It helped me a lot thanks
really so thanks for that information
Thank you! you saved my life!
why?
Thanks, can you clarify one thing. If the static pressure is too high , the CFMs drop but the air velocity is increased ? So even though there is a cfm drop the velocity is increased and can cause noise issues?
You can’t use a testo 510 and pitot tube to measure residential airflow. The range of the 510 is not low enough and the resolution is not fine enough
You may be confusing two things.
Total External Static Pressure (TESP) in the system is the load against which the distribution fan has to "push" the air. Higher TESP usually means lower system airflow or excess energy use in an ECM motor.
Measuring Static pressure drop OVER an A-coil or heat exchanger is an indirect method to determining air flow (CFM) via pressure drop over a component and brand and model specific manufacturer data.
Excessive CFMs (airflow) through grilles and ductwork can produce excess noise
If you have any additional questions, please do reach out by email at billy@trutechtools.com!
Big thumbs up for this video. Can you tell me what is the lowest speed this setup can detect? I'm looking ducts having airspeeds as low as 2 m/s
The key is choosing the correct manometer with sufficient accuracy for the flow velocity (total/velocity pressure). To measure under 3.5 m/s (700 feet per minute) you need a finer resolution manometer like the TSI AirPro 800 or the testo 512. The pitot tube can be the same, just the manometer changes.
Hey, Bryan, I was recently listening to one of your podcasts, and you were referring to a video you made with a pitot tube that you did incorrectly. Is this that video, or did you get rid of that one already? Thanks so much for all the content you put out. You guys are doing a great service.
This was the one. Bryan was using a digital manometer that did not have high enough accuracy for the relatively low flow pressures in a residential duct. Only when flow velocities are above 700 Feet Per Minute can a manometer of this type be used effectively with a Pitot tube.
If I file down a sharp bur on one, does that make me a pitot-file?
How do you do this on flex duct?
How much is this one instrument? Thanks
we have testo440 dp. can we use this pitot tube (0635 2045) for it?
Thank you you explaination is good
Again thank you good and easy way of explaination
4:29 Duct Travers
Whats the code for tools? " get school " "getschool" " get schooled" getschooled" ?