Measuring Total External Static Pressure

Video demonstration by Jim Bergmann of TruTech Tools of how to make a total external static pressure readings on a furnace and how to calculate what the external static pressure will be before replacing a furnace or air conditioner.

[jonwiersig]

Great video. Clear detailed explanation and example of where to measure static pressure. As an engineer, I was impressed with your use of fan laws for pressure drop. Great job!

[robertstinnett]

Thank you sir! I train service and start up techs. I am going to make this video a requirement. Most techs do not even consider or think of static pressure. This definitely shows how important it is.

[dissociativecat]

this is one of the best videos I've found about this subject

[garysmith]

You have a great way of explaining things you need to keep adding more videos ASAP

[HVACShopTalk]

Very good instructional video. Most of the systems I check are well above the recommended static pressure. I like the steel plugs- I am headed to trutech now for those. Good job.

[soloch]

Love the video thank you for all the great helpful information keep them great videos coming 👍🏻

[karlxmas]

11:42 - "Awwww Shit"- then carries on. AWESOME!

[BouncyThrone]

I may be missing something, but aren't y'all in the business of actually selling meters, devices, tools, and equipment to tradesmen and the like? If so, I'm impressed. I can't tell you how often I've attempted to consult and extract info from a seller only to find they are completely clueless of the products they're selling. So this is refreshing..
Not sure what happened at the 11:40 mark, but this was a great tutorial..
I recently grabbed that Testo 510 to upgrade from my analog. It seems very accurate and stable, but I can't help wonder how durable it's going to be. It literally reminded me of one of those child's play plastic cell phones when I first handled it.. perhaps I just equate weight with quality, and next to my fluke with that big yellow cover, it just doesn't feel quite as durable, but perhaps and hopefully I'm missing something, and it will prove to be a great asset..
With all the choices you have a hand, I'm guessing you like it if it's the one you chose for this video..

[HBSuccess]

One nice thing you can do is use a perm magnet on the cabinet or plenum just below where you’re drilling to catch the drill filings when making the test holes.

[gwengreer]

Very good teaching on The Measuring Total Estatic Pressure. Gwendolyn Greer

[TruTechTools]

They are perfect for that as long as the hole in the inner wall is sealed with high temperature RTV. You can easily remove the plug the following year for testing. When you say "rated" however, there are no ratings for any type of sealant for b-vent that I know of. We do however have copies of letters from all of the major b-vent manufacturers on how the hole is to be sealed. You can email us or call us and we can get them to you via email if you need them.

[chrissipple]

One thing that might help is to cut a small piece of sheet metal and drill a hole in it and then tape it over the limit opening. you will have a removable port for static pressure readings. Also you can not suck or draw pressure you can only push it by the pressure difference.

[TruTechTools]

Thank-you all for the positive comments.

[hvac]

Thanks. That was very informative.

You put the static tip pointing up (with air flow) in blower section.
In the diagram it is in blower section, reversed, pointing AGAINST air flow.

Please clarify.

[NoneFB]

I liked that 3D sketch of thee pitot tube. I’ve never seen that before.

[dpeagles]

One of the best explanations I have seen.

[TruTechTools]

Thanks a lot for your feedback. I am trying to get more done. It takes a lot of time. I am glad that you find them useful. Let me know if there are topics of interest that you would like us to cover.

[munawarsoomro]

Very nice video thanks. I haven't found a video where one can make airflow measurements with hot wire given supply taps generally come few inches off of the duct connection to evaporator coil.

[enricoricci]

Change That Dull Drill Bit !! Great Video !!

[willpartin]

Thank you for all your great vids.
I was wondering if you can ever have too much return ducting.
After watching your videos, I checked my external static and found 3.5 and 3.5 for a total of 7 in WC .
Filter drop is .18 INWC ( 5 inch air bear) and a\c coil drop is .21INWC. ( 2.5 ton N coil.)
The temp rise is 70 degrees in heat mode. Rheem says 40-70 rise is okay, so I'm at the high end of acceptable . Shooting for 55 degree rise.
I'm thinking I might need more returns and supplies but don't want to over duct it. Any help or advice? Also, when is was installed they added one 10' and one 8 inch flexible return duct.
this is a 70, 000 BTU Rheem 95% that replaced a 115, 000 Ruud 95% furnace. Thank you



Reply
Thank you for this vid
I was wondering if you can ever have too much return ducting.
After watching your videos, I checked my external static and found 3.5 and 3.5 for a total of 7 in WC .
Filter drop is .18 INWC ( 5 inch air bear) and a\c coil drop is .21INWC. ( 2.5 ton N coil.)
The temp rise is 70 degrees in heat mode. Rheem says 40-70 rise is okay, so I'm at the high end of acceptable . Shooting for 55 degree rise.
I'm thinking I might need more returns and supplies but don't want to over duct it. Any help or advice? Also, when is was installed they added one 10' and one 8 inch flexible return duct.
this is a 70, 000 BTU Rheem 95% that replaced a 115, 000 Ruud 95% furnace. Thank you



Reply