How to use Static Pressure to Measure and Set Air Flow

In this session from the 2nd annual symposium Eric Kaiser shares his knowledge on how to effectively measure static pressure and what you can do with it to solve system airflow problems, set air flow and select filters.
Read all the tech tips, take the quizzes
and find our handy calculators at www.hvacrschool.com​

[@staticpressurenerd5182]

Fantastic video!

[@MrThumper1440]

I just came here to hear you sing. “We are the champions”

[@greenpoint23]

Eric is truly an expert in his field and gives an A+ presentation. Thanks for posting HVAC School

[@gamking7987]

What a lesson! This is pure gold.

[@burnardhayes8995]

How can I join the class

[@jimprisby5463]

Thanks for making this available Brian, Eric did a fantastic job!

[@kateramirez1574]

Jeep Caldwell

[@mitchellarmyguy2515]

If this guy doesn't make it in HVAC he can be an editor in the next spider man movie

[@Ali_Alhamaly]

Eric Kaiser explains stuff really nicely. really great teacher. Bryan Orr, please have him more often here on youtube as well as on the podcast

[@lovemyshepherd]

Nicely done. Gets a clear point on the basics and defines some of the reasons why the air does and doesn't do what you think. I was impressed with the motor differences. We are always in a hurry so we look at the chart dial it in as good as it can be and call it a day and actually we should be looking a little harder at the charts. I wish he would explain when you should be concerned with the readings that show larger duct issues down the line and how to read it on the monometer. Thanks for sharing.

[@kieffersheatingcoolingv2.03]

Thanks for all involved in this video. Super helpful and extremely well done.

[@sportsman042002]

Wow thank you Bryan I am really greatful for all you do for others education and allow us to have access to like this video hope you never grow tired of being a blessing!

[@alexcuster1280]

Great video, thanks, my dual Fieldpiece manometer and dual Fieldpiece thermometer are invaluable on certain types of no-heat calls!!!

[@resurgensix]

Interpolate is my new word of the day! 🆒 Great presentation Eric. Really coming to understand static pressure now.

[@fernandorosillo9715]

Awesome class about pressures in ducts. It's a great master class.

[@REFRITEKREFRIGERACION]

Thank you for all you guys do. Really need this video.

[@Graham_Wideman]

I'm liking this season of "Magnum PI, HVAC Detective"!

[@Sam-dc7qp]

I really do appreciate all the videos you post they really come in handy being fresh out of school make a lot of things clear that i didn't understand stand from school and i get to really go over things over and over till i truly understand it thanks again

[@BYENZER]

EXCELLENT INFO! THANK YOU!

[@igorc3989]

Great video! Thank you.

[@joeschebler6236]

Thank You very much for sharing this, it was very educational

[@Zed20000]

Beautifully explained every detail

[@brianlittle717]

Thank you guys for this!

[@AQ22W]

(1) Really Enjoyable Presentation! (2) The visuals, along with the Pointing Directly to what was Being Explained, should be incorporated into a lot more videos. (3) Pointing, Highlighting, and Animating PARTS, are the "Subtitles" of Sign Language.

[@SantiagoRodriguez-mi9zt]

Thanks a million for this this!!! AMAZING!!!!!

[@fernandomeier4386]

Great video! Very interesting!

[@corruptedbrain6]

thank you for this video ! This man is too smart !

[@jamesgutierrez8606]

goood intell on the static pressure measuring points in the duct system, kinda got lost on the airflow chart

[@yupinmywhitet2]

This is a great educational video

[@NoorRefrigerationsystem]

Wow Amazing video Love you sir ❤️

[@ducharmehvactraining925]

Great job thank you!

[@moideenyousaf3757]

really very helpful, thanks

[@sabanilla10615]

Thank you very much for the info.

[@user-bz1om6if1d]

Thank you for sharing!

[@will-smith-nh]

Excellent video.

[@andreaskoufettas6979]

Amazing video thanks

[@hectorgarza265]

Don Frye is an hvac-r tech wow lol great video

[@mbaphna]

Thanks for nice knowledge shared

[@luismorales9319]

Well explained..thanks

[@72jarul]

Great video

[@No_prejudice_pls]

Thanks for the session. Its interesting. I work with railway HVAC systems. Nobody talks about Static pressure. Not even customer. So i will see now why filters are not getting dirty on one particular area.

[@tomorrowsyoutube7138]

My mustache game is weak compared to this man

[@erickaiser501]

Now I have that going for me 😂😎😎

[@jamairconditioningvideos3918]

Nice video 👍

[@danmartens1282]

Ran across a system with high static .86 2ton condenser 2ton coil Blower set to high measured cfm at 1285(5 times on avg traverse) on the return. Will lowering the blower speed affect static. Issue getting air to one of the upstair rooms above garage. Thanks

[@germanagudelo6533]

Thank you so much. I got a question. I come across very often of equipment with no manufacturer nor design info. How can I verify that my readings are what it was supposed to be?

[@LispyJesus]

Yeah this is an issue I get a lot. Old systems, with no Manuel’s and it’s impossible to find them online. I guess you could traverse a duct with velocity pressure readings and calculate velocity then airflow, or even easier and quicker traversing with a hot wire anemometer, this would give you the actual CFM. Testo sells one for about 100 on Amazon, which is real cheap as far as hot wires go. You have to use your phone for the brains of it though, so it’s not really stand alone.

[@whitesheatingairappliancer7101]

Eric are you that guy that played on WKRP IN CINCINNATI or ANIMAL HOUSE? 😂😂😂. I'm kidding you. Heck of a resemblance. GREAT VIDEO APPRECIATE THE TEACHING.

[@erickaiser501]

I’m not sure how to respond to this 😂😂 Those were both good shows, though a little before my time. Thanks! 😎😎

[@mtbphil168]

I set the constant torque motor air flow based on the static pressure and blower tables to hit 1000CFM. However, the CFM from the air filter tables was much different. How do you reconcile the difference? I assumed I should trust the blower tables more. Thanks

[@aaronmiller112]

I love this guy's moustache

[@frankgall6]

Can not wait for retrotecs single channel 🥰

[@haithamabouzaid8161]

Thank you sir

[@deanstuder1775]

Got a question. And I see you take questions at times. I'm a newbie and my micron meter broke on me. Went to bed at 24,000 woke up to a half micron . Outstanding I thought then charged back up R22 4 ton and find I have ,e degrees across my filter drier and would like to know if I paralleled say five filter dryers together in a manifold arrangement . Could I substitute that way compared to 500 microns for thirty minutes. Just allow the filter driers to remove moisture without the restrictions. ,? I know I think outside the box but suppose I were on a shop trying to save perishables and only chance I had ,?

[@chefitaliano74]

I have know for years that my upstair unit was oversized due to high moisture level, noisy duct and cold/hot spot throughout the upstairs. After measuring TESP, on return side reading shows 0.3wc and 0.6wc on supply side. Assuming that all of the flex ducts are intact, I wanted to theorize that I will need to add more supply duct in order for me to reduce static pressure on supply side. Technician suggested adding 2x6" supply runs to solve the problem but after watching your video I noticed that you've mentioned that by reducing static pressure on the supply side, we are now able to move more air trough the system which will now cause the static pressure on the return side also to rise. Without knowing how much the static pressure will now rise on the return side, should I go down this route to fix the problem that I'm currently experiencing or just have a new proper sized upstairs unit? (my current CARRIER unit is 15 yrs old but never gave me any problem during the past 6 yrs that we owned the house0

[@davepetrakos1192]

You must start somewhere, and he said it should be with the side having the highest pressure. Then run your test, again. It's a bit like doing a jigsaw puzzle. Keep plugging away at it until you are happy with your static pressure readings. Cheers.

[@pamvic]

very informative

[@deekshithns8491]

Sir, I have one query, When designing the HVAC supply duct system, After calculation of ASP from the manufacturer blower data (ESP- Device pressure losses). That ASP will become the pressure drop budget for the duct system. Now if we are designing the duct system with equal friction method based on FR calculated...and carrying out CFD analysis of designed duct, the solver fetches static pressure and total pressure data w.r.t our design. Now w.r.t previously calculated ASP which is our pressure drop budget, say some 0.4 inches of water gauge. Now inorder to check whether duct design is within the limits as per ASP in CFD analysis tools. which pressure drop should I need to consider ( it's a total pressure in the volume of air or it's difference in Total pressure at inlet to outlets, or it's a max static pressure developed in the air volume inside duct) kindly clarify

[@numerouno4168]

Nice 'stache, dude! 👍👍

[@shifter8207]

I would love to see where to test on a package rooftop unit

[@erickaiser501]

Inlet and outlet is normal for ESP. Have to be careful with penetrations on an RTU so not to cause leaks. Screws with gaskets and a ball needle are your friend here.

[@shifter8207]

@@erickaiser501 thats what i was wondering was placement of readings. Thanks Eric

[@user-pe8lm2qk8u]

Greats 👍!

[@Terrenceaj]

The Aaron Rodgers of Static Pressures

[@RickSegui]

What about package units. What is the best procedure and test locations?

[@erickaiser501]

Generally speaking, at the inlet and outlet. It also depends on wether or not a filter was included in the factory chart.

[@HVAC544]

I know you don't see many Gas furnace AC system out there, but I was wondering if you think those systems have undersized ductwork generally. With coil and filter pressure drop you can easily be at 0.5 static. I listened to your podcast with Jack Rise and it was really eye opening.

[@erickaiser501]

Most systems in general have either undersized ductwork for the equipment, or oversized equipment for the space. The combination of both makes for a lot of issues.

[@HVAC544]

@@erickaiser501 Thanks, been trying to educate myself more on duct sizing through manual D not much information out there. I was taught to just use a ductulator and set it to one friction rate for every job. Which is entirely wrong! My own system in my house is at about 1 inch of static right now.

[@erickaiser501]

@@HVAC544 I think most of us were taught that, and you are correct. A single friction rate will work if we only put 100’ of straight duct on every system 😂

[@Brad.W]

@@erickaiser501 that's the way my system is recently had my condenser and air handler changed out to a 5 ton because I was on an undersized 4-ton system since I'm in a manufactured home the manufacturer says my duct system is rated for 55,000 they installed a 5 ton 2 stage American Standard condenser with a variable speed blower my pressure is in my vents went from .5 to almost 0.8. they had to add a new return above my air handler to lower my pressures to a total of around .87 to keep the thing from sounding like a jet engine every time it ramped up to that 5 tons. They wanted to redo my entire duct system but wanted nearly $18,000 to do so which was more than what my air handler and condenser cost combined. Long story short the thing rarely kicks up to five tons so the cost wasn't worth it to me.

[@erickaiser501]

@@Brad.W so here’s the next question, is your house comfortable and staying at set point?

[@JohnGaltNikolaTesla1]

Why not use a hot wire to measure velocity, then taking area to compute CFM?

[@user-kr4vy8xn4q]

motor will increased rpm seldom if enclosed system is not operate and no air supply in ducting?

[@wallacegray7681]

so how do you measure ESP in flex duct?

[@ClaudioVolber]

Omni man!!!!

[@hectormercado8065]

How do you check total external static on a package system?

[@richarddonnell3918]

Great question

[@p-cca6262]

Hi all, Does anyone know what happens when a trane 3.5 ton unit is installed with bottom return and side return and filters installed on both sides? Any suggestions will be Appreciate.

[@1MaximusDecimusMeridius1]

What happens? Should be plenty of return for a 3T

[@fasahathussain3684]

For air circulation purpose

[@publicmail2]

The reason why SP are over looked by too many companies is the money isn't coming out of their pockets, and customers don't understand it and wont pay for corrections even though it most likely will save them 50% on kwh.

[@metal2444]

They where all sold on true variable speed on the better airflow compared to p.s.c. and TEN YEAR WARRANTY cut paste new unit in , after that the price on o.e.m. replacement motors $1400 still have bad ductwork should have stayed with p.s.c.!

[@moparerrnocar]

Wouldn't air down stream of filter have a greater negative pressure? Wouldn't all air in the return be a negative? Who puts filters in the supply??

[@arthurherring2957]

Yes

[@baivabmitra376]

What I did not get is this: Assume ESP comes out to be .64. Then the install doc. blower speed charts show (for example) for .64 one can have 950, 1050, 1150 (max) CFMs by toggling some switches on the board. We're talking of c/torque 1/2 HP blower. Thus - the question which I presume got answered is which CFM then is correct? 950 or 1050 or 1150. What I have seen is most HVAC guys set it to max and forget it. (We are discussing AC cooling here). What I understood or was told was this: Once you have a rather unacceptable ESP (.64) and you prefer to keep it at .5 and lower then change the blower speed. Once done, the ESP will also change, as a result. Do that iteratively across the values till you arrive at the lowest ESP. Let's say for that the blower was set to 1050 and the ESP dropped to .55. BUT, therein lies a bigger problem. By dropping the CFM the air coil will get colder now (less air). If it's a TXV then there's a possibility of a freeze. That's why he is recommending doing the ESP BEFORE setting the charge. But 99% no one does that, before. An HVAC guy told me, at this point if the air coil temp is 25 to 30 F less than return temp, you're good. Not sure how true is that.

[@JohnnyJr396]

Help guys. I’ve seen too many things that contradict tesp and cfm. Is it possible to have the right cfm but have too high tesp? It seems some gurus say tesp has its place but to get the right airflow other test need to be done. So going back to my question is that possible and is tesp still relevant?

[@nickmerc9299]

I have a question about sub cooling

[@caru3257]

people are waiting for your question.

[@louismays7810]

Smart man i miss the 80s i was more intelligent then than i am now

[@musicjunkiesstudio]

That stash bro

[@tommeyers974]

The HVAC videos do not discuss the increase in Electric Consumption from High Static conditions. Over the life of a Furnace, or Air Handler, the waste in power is Staggering, all paid for by the unsuspecting home owner. Ex: (At 1 amp per 0.1 inch (my furnace/AC is .2 over)=0.16KWH/hr., 1,250hrs/year, 25 Years, $.185/KWH gives $950 wasted, over the life of the unit.)

[@blh3741]

Great video! Man...every time I see his mustache, it reminds me of Freddy Mercury! :~)

[@publicmail2]

static pressure is very easy to understand, just learn the basics and it will all make sense.

[@richardg2904]

Great explanation on the effect of the filter! A couple of questions. If the furnace (or air handler) is configured with two media filter units (not stacked), then I assume that each filter contributes to the total resistance. For example, two identical filters would effectively double the resistance (assuming the same air flow), Is that correct? This raises another question. How would the configuration of the plenum and return ductwork affect the air flow into the two filters. For example, if all the return air comes through one shared plenum that splits (i.e. a “Y”) just before the filters, would the air flow into each filter be halved, also reducing the resistance of each filter? For a more complex example, what would be the effect of configuring each filter unit with its own return plenum and return ducts - essentially two different return ducts sharing a blower? Seems like that has the potential for creating imbalance in the return air flow.

[@BYENZER]

Hey ERIC, you interested to know how a famous Berkeley professor made the news, when his student's GPAs skyrocketed? Yes? Well here tis! Professor counted the minutes between TV commercials. Avg 7 min. Then he simply set a silent alarm for 7 min, IN his class lectures. At 7 min, he refocused the students attentions, by simply, TELLING A JOKE! GPA's skyrocketed!!! Today, it's down to 3 min. Progress?

[@jamesgutierrez8606]

sounds like more complicated calculations in an already complicated & laborious trade

[@corruptedbrain6]

true true but to more you know the better

[@arcad1an292]

Measure or guess, professionals do not guess.

[@mikefreedom5612]

I think it's a good video but he delivered that few minutes instead more than 1 hour

[@petermoore7500]

Lousy communication, all over the place

[@hvac2.038]

Great video and even better mustache.

[@coolrich8781]

@1:24:08, There is nothing wrong with asking questions in which you are looking for clarification, but it seems as if the guy with the red/orange sweater is attempting to standout, and be a KZbin star, or start his own channel with the questions he’s asking.😂 I heard four of them already and it seems as if he doesn’t even know what to ask. 3 students left already and if he keeps it up he’s gonna be the ONLY one left in class.🧐🤔🫣😂

[@Irowthe1x]

Great video