All right, so, let's get started. All of you should be able to see the presentation on my screen. If, for some reason you don't see it, please let me know - or if you have any questions as we go along, feel free quickly. Housekeeping Nate credits will be given out to everybody who provided their Nate ID and who I can show through the software that you were present through the majority of the presentation.

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Eventually, all right here we go proper use of manometers for HVAC technicians. That's what we're covering today and so we're gon na start with the basics. First thing is history manometers: where do they come from? How did they start well? Really a manometer is just a measurement of a column of liquid, and so the some of the early ones were water, manometers, mercury, manometers, and so, when you hear things like inches of water, column or millimeters of mercury, these all came from very simple columns of these Fluids, so if you see the the image here, one of the this is one of the early manometer patents. This is actually from the Dwyer company, which is still an active manufacturer of different air measurement tools.

Very good quality company - and it kind of shows that for some of the early tools for measuring inches of water or mercury were very simple, there's just just you tubes, and so that's why they call them a u-tube manometer and they still work frankly they're a little Cumbersome views, but there are some people who still choose to use them. They generally lack a little accuracy only because so much of what we measure in the analog scale, because a lot of people will ask this, let's say well, why not use an analog gauge the problem with an analog gauge? Is it relies on your ability to read, find gradations on the gauge scale, which is very difficult for most of us to do in a really fine way? It's the same thing. People will ask why you can't use a suction gauge in order to measure microns of mercury, some microns on the vacuum scale, and the reason you can't is because it's truck it's like trying to measure feet on your odometer in your car. You can't you measure miles in an odometer, that's what it's designed for, but you can't measure a smaller unit of measure on that really big scale.

And so that's what makes it challenging when you're, trying to measure things using more analog methods? And so the digital scales were now, you can measure in the tenths and hundredths of an inch of water column, for example. Give you much better and finer resolution, but this is where it came from. And so when we say a an inch of water column when we say a millimeter of mercury or when. Even when we say a micron and a lot of people, wonder where the? Where the micron came from and a micron is literally a millionth of a meter of mercury column, so a micron being one millionth of a meter, and so when we say the micro engage or microns of mercury.

That's what we're talking about, and so that's just another scale in the case of manometers, we generally measure in inches of water column. That's the most common measurement that we use for the two most common types of measurements that we do, which are gas pressure and static pressure in the ductwork. And that's what we're mostly going to talk about today. But we're also going to talk about some other things.

That you can do with the manometer and some of the common confusions related to a manometer again as we go. If you have any questions, feel free to ask it in the chat. How a manometer works a manometer measures, a differential rather than an absolute pressure, and that's really important. I mean it can measure an absolute pressure, but we're going to talk about how that why? That varies because, when you think of something like a micron gauge, because a lot of people will say when they can, I talk a lot about a micron gauge, because it's another type of fine pressure measurement that we do is technicians.

People get a micron gauge and I'll say why can't I zero out my micron gauge and that's because a micron gauge is already calibrated to true zero pressure. So, that's where that it's you know, 760 mm microns of mercury is atmospheric pressure and everything is calibrated to zero microns, which is no pressure at all, whereas a manometer is calibrated in between its two ports, if it's a two-port manometer or in the case of the New field piece: JobLink manometers, it's calibrated, you have to separate manometers and you calibrate them independently to atmosphere. But you zero them out. And when I say I'm saying calibrate and I didn't, I don't mean to say that when you zero them out to each other, you're measuring a pressure differential from one point to another point.

So, regardless of the type of manometer using you're, always measuring a differential between two pressures and generally speaking, for example, when you're measuring gas pressure. You're measuring a differential between the room that you're in depending on the altitude that you're in, but just the regular atmospheric pressure. That exists and the pressure that's coming out of that gas valve so you're measuring that differential pressure. But you could also measure like in the case of static pressure.

You could measure the differential between the negative side of the system and the positive side of the system before and after an air handler or a fan coil, and that would give you what we call totally total external static pressure and it's it's measuring across those two Ports and traditionally with a two-port manometer, like the one shown in the illustration here, you have ap1 and ap2 port on that manometer and those can be reference to each other or in the case of the one shown here, the field piece which I've actually always liked. This about this manometer, it also references to atmosphere, and so, rather than just being one pressure reference to the other pressure, you can reference p1 to p2 or you can reference p1 to atmosphere or p2 to atmosphere, and that's a really nice feature, because a lot of The measurements that we do, we really care, not just what the p1 and p2 differential is, but what the pressure in reference to atmosphere is. One question that we already got is: how does high altitude affect digital manometers, and the answer is: is that as long as you're zeroing them out to atmospheric pressure, it doesn't affect that's the nice thing, whereas atmospheric pressure does would affect it. If you took a manometer and you were down at sea level where I live next to the ocean and then you'd jumped in an airplane and flew up into the mountains, well, now you would notice that it was way out of calibration all you do now.

Is you just zero them out to each other and zero them out to atmosphere? And now you have these multiple reference points and so again in the case of a traditional manometer like the one shown here, you would have the reference between p1 and p2. That's common! Some manometers don't have an atmospheric reference and so you're only referencing them to each other and which is why you would zero them out open first, so you would open them up. You would zero them out to atmosphere, and then you would then you would. You know work against each other, which is similar to what we're doing now, but you also have ones like the one shown here that is also referencing to each other and referencing to atmosphere.

So again, you just have to know always when you're using a manometer. What are you referencing to, which is why it's so important, that for normal use you zero out at atmospheric pressure, both of your probes with them open or with them? You know with the probes that you're going to be using on them so like, for example, with this, I would zero it with the probe in place. So that way, I don't you know, get a little hit when I go to put the probe on that may be affects the sensor. This would be sort of the ideal way to zero out in atmosphere, and then I would take it and put it in the duct.

That would be ideal, and so that's part of the beauty is that it isn't affected so long as you follow that process by changes in altitude and that sort of thing, at least not for this type of measurement. The type of measurements were going to be talking about today with some others, for example, air velocity. It gets a little. It gets a little different, but for what we're doing here it doesn't you don't have to make adjustments so again, always remember what you're referencing to and in in the case of a static manometer where you have two ports on it.

You're gon na have that p1 and p2 pressure port in the case of the JobLink manometer you're, going to be able to adjust between p1 and p2 by sliding this little slider back and forth, which is a nice feature of the new job length. Manometer. Any questions about that anything you want to add Tony. I know you got a little lag on your end, but anything you want to you want to add so far hope you muted.

Let me unmute ya. I don't know why you muted, they are good all right. Now can you hear me, okay, ya, know just that there was a question in the yes just that there was a question in the chat about a magnetic Gila cage and whether or not that is accurate enough. I guess what I would say to that is.

If we're talking about resolutions of static pressure, it probably doesn't have that type of resolution for you to be able to to get a good static, static pressure reading, for you know your target or sterno static pressures and things of that nature, but for gas it should Probably be okay, I don't know what you think about that. I mean a magma. He like yeah, so a magma hillock is specifically designed for static pressure. That was its application.

That was what it was designed for. In fact, you weren't, even I don't know that you were supposed to use a magnet. He like for gas pressure at all Magna he like is actually to my understanding, is actually a trademark brand name of Dwyer and I have a magnet like I've used one for years. The challenge for the magnet helix is that it's very sensitive to being it has to be level it.

If you move it or bump it, then it you know, then it goes out of calibration. So it's a more sensitive instrument and I would say if you've got one and you've been using it for years and you like using it. That's fine. It obviously doesn't have a lot of the capabilities of a digital manometer and it isn't going to have the resolution of additional manometer, especially when you get down into those tenths and hundredths, but but if you've used to using it, Magne helix been used for years.

It's like it kind of falls in the same category of that you tube water, manometer or the incline water manometer. They work just a little more cumbersome to use and a little a little trickier, a little more susceptible to being unlevel or those sorts of things. Alright. So we're gon na go in the next slide all right.

So let's talk a little bit about the pressure scales, the the units, the units of measure that we use first, is first and most common would be inches of water column often shown as inches WC, and that is the standard scale that Tech's used for manometers. Pretty much across the us now in other markets, other parts of the world you're going to see a lot of different pressure scales being used, but in water column being by far the most common in our in our industry. Pounds per square inch is a very common pressure scale, but it's kind of too large for most of what we do because there's 27 point: seven one inches of water column in every pound per square inch middle bar M bar! That's what that stands for. That is a scale that you're going to see in other countries more more often millimeters of water column.

Pretty rare I'd. You don't see that much. But again that would be more in metric countries and then the Pascal and you do see a Pascal. So a Pascal is point: zero, zero, four inches of water column and - and that is a very, very fine scale of measure - and it is a it's essentially a bar which is roughly one atmosphere of pressure divided by a hundred thousand.

So it's a very universally used, but very tiny scale of pressure and that's where you get into using precision manometers for things like blower door, testing and zonal pressure and balance, and that sort of thing that's that's more what you would that's more what you would use That for, but mostly what we're using as technicians, because, again I try to keep this pretty practical to the audience as technicians we're generally going to be using inches of water column all right. So what can a manometer do with a manometer and again good? No, I was just also one thing about the pass scale unit of measure is that it is also more common in international countries than you know, but here in the US, but yeah a lot of people use it yeah for fine units of measure. Pascal works great. So, let's talk through some of the some of the things that you can do with the manometer measure pressure differential like we talked about, that's the that's the utility of it.

That's what you do with it: you're measuring differential pressures. You can measure gas pressures, that's one of the things that probably they use most for, and it's universally true, because in order to set a gas pressure, you need to have a manometer duct static pressure and now again quickly about that. Subject of because I just made a statement in order to set gas pressure, you have to have a manometer. There are some old-school tools: gas pressure gauges, for example - that were analog gauges that people use for a long time.

There is no advantage because people will say you know I like the old-school gas pressure gauge, there's no advantage to using those over a digital you're, not gon na. Have it's fine of adjustment. You're not gon na have the resolution. I probably still have one in my truck somewhere, but I would definitely suggest that you go to a monitor and also the other advantage of a manometer is that it has multiple applications where a gas pressure gauge is a single use tool.

Maybe if you have one as a backup in case your batteries are dead or something happens that makes sense, but but as a primary tool for gas pressure, you would definitely want to use a digital manometer nowadays. So the gas pressure would be a huge one. Doc, static pressure would be the number two most popular and then you get into things like pressurization and depressurization of rooms, air velocity using a pitot, tube and hydronic liquid pressures. Now those are specific use cases for a specific type of manometer.

There are pressure applications where you can use a technician, manometer like the job like manometer that we're showing here, but that's when your pressurization and depressurization are greater than what you're typically going to see and residential applications. And this is a common question, because people will look at a manometer like this and they'll say well, can I measure pressurization or depressurization of rooms? Can I measure air velocity with this, and the answer is yes, you can, but they have to be greater they're generally. In cases where you're moving greater volumes of air that that's practical generally in residential, you don't have big enough pressure differentials for a tool like this sort of your utility technician, manometer to be practical for those purposes, but just recognize that when you see the word manometer A lot of times people will say: well, you can do use a manometer for that. You have to know specifically what type of manometer you're talking about and what pressure range you're operating in and, for example, hydronic manometers are specifically designed to measure liquids.

You know so you're gon na use a hydraulic manometer for things like water or glycol you're, not going to use a manometer, that's designed for gas pressure or air with water and glycol it's not it's. That's not a specific design. Anything to add there Tony no, but covers it good, all right, all right so zeroing versus calibration, and I do this all the time I did it at the beginning of this of this webinar or, I will say, calibrate your manometer and that's why I put this In here, because it's just so often, then we make this mistake. Zeroing is what we do when you take it out of the box before you use it or take it out of the bag before you apply it, that's what you do.

You're zeroing it out to each other and to atmosphere, that's really what you're doing you're zeroing, P, 1 and P 2 to each other and then zeroing them both to atmospheric pressure by taking them out calibration is something that happens at the factory or by a designated Calibrator, there's no there's, I don't know of any manometer I'm maybe maybe there is one out there that I said that I don't know, but I don't know of a manometer that you truly calibrate in the field. Calibrating is setting in the scale, and you have to work against kind of a known pressure. It's a very fine instrument, grading process that has to be followed there. It's not something we're doing in the field in the field, we're just zeroing it to atmosphere now.

Luckily, most of the field manometers we use will, though they are fine instruments, they're designed to be rugged, they're designed to be used in the field, and so they can take a pretty good beating and still do their job. Well, and all we have to do regularly is just zero them out before we before we use them. Let me see there was a question here. One of the questions is: are there just two types of manometers and the answer is no.

I mean yes and no there's really only one type of manometer, and that is a manometer, is a tool that measures the pressure difference right I mean simply but modern. In the modern era, yeah really three different types of manometers that we see, we see the utility field, technician manometer, which is what we've got here. You see a manometer that is a precision grade manometer, that's designed for measuring tiny, tiny pressure, differences that you would see in companies that make blower doors and that sort of thing, and then you would see wet manometers is what they're often called or hydronic manometers and Those are all three kind of purpose-built, with the technician utility manometer being the one that you're going to use for static pressure and gas pressure, which is by far the most common test that you're going to do. Alright, so zeroing made simple, you know, zeroing is a really important part of the process and it's something that you've got to do every time.

So this is actually Tony zeroes it out before he puts the hose on and then see all he does with this manometers. You literally just press it, you don't have to long hold it, you just bump it it zeroes out, then you place the hose on or put it into operation. Now. One question that's come up with this is: is it necessary that you have the hose assembly and the tip in place first before you zero, and the answer is no, not really you wouldn't want to take it and you know blow on it or something you know In between you would want to make sure that this is open to atmosphere and now I'm having a hard time getting it off here, while I'm on air.

This is open on atmosphere and then you press the button just quickly. So it's already on it's already connected to the jumbling cap. You just press the button quickly. It's gon na blink, the blue light, and that tells you that it's zeroed out you're gon na see that on your display, whatever device you're using and then you can place it back on or if you would.

Rather, you can zero it out like this before you insert the probe into the ductwork in the first place, but zeroing is an important part of the process, but it is not calibration and that's an important, important distinction. Somebody's asking here when should a manometer need calibration? I invariably the field - that's what's great about this setup specifically, is that it comes with two separate and distinct penomet errs, so you can check them against each other. That is not a laboratory grade test, but it's enough for us practically in the field. It's the same.

That you would use with your refrigerant gauges in the field. If you have a gauge that you think isn't reading right, what do you do? You grab another set off the truck? You borrow one from your buddy and you test it and you see if they're measuring the same now that doesn't tell you which one is right or which is wrong. So maybe you try even another set and just kind of get a sense and that's how we do it in the field. That's the practical way but I'll.

Let Tony answer the question for the guy who asked it. You know how. How often would you want to calibrate something like this or do you recommend that at all yeah, so, basically, what we would say is if you, for whatever reason, have any doubt of the accuracy of of your tool, you know, look, you know, like you did what Brian said, like you, did a side-by-side comparison with the friends tool and you just weren't really satisfied with it. You could always ship it back to Philippe's, and then we can test the accuracy for you and it lets.

You know whether or not it still measures within the within the printed specification or not, so so so to answer the question: when should you get these calibrated, I mean I agree with Brian. There really isn't a need to often, unless you really feel down about the readings, then you could always send it back to us and we will test it out for you yeah from a practical standpoint, though, in the field we're generally going to start by checking against Other tools and hey one way of looking at it is it's always good to have a backup set of pretty much everything that we use anyway. So you can always get a backup set test against that and then you know worst case scenario. You've.

You know you find out that it isn't as accurate as it could be five years down the road or something like that, and now you've got a knife at another. My good buddy Kenny C is here Ken Casebeer and he it's always talked about tool redundancy. We were just talking about this on a recent podcast, and that is really important. You know have have some redundant tools so that way, you've got something to check against, because otherwise you are a little bit stuck out there and that's true of all tools.

One question was: can you use it to test pressure switches like you can, with a dual port, manometer and yeah? The answer is yes, you can use pressure switches, you can get little barbed keys and do it that way. That's that's one way. People live off and done that you know they have a barbed tee and then you're measuring off of it. While it's in operation, it doesn't do, and I don't remember the model - maybe you remember Tony, but the model of field piece manometer that actually can pressurize the pressure switches out based on its own pump.

It doesn't do that. What what model is that the SD mm thick yeah, and that is a great tool and I have a bunch of those to put it on the field, and it really is a great thing, but this is not. This is not that. So that's a different different thing altogether and just for those of you who are wondering this is peach juice.

This is not Tony thought. This might be gin or something like that. No, it's just peach juice, which it's like who drinks, peach, juice, weirdos. That's who that's? Who that's the answer? Alright, moving on the next slide, utility versus precision versus wet? We already covered this, but let's cover it a little bit deeper about when you would need different ones, technician grade, that's what most techs need in the field.

I'm not gon na suggest that most technicians other than those who are working on hydronic systems, regularly need anything other than a technician grade. Manometer like the one we're talking about today. So most Tech's need a field grade dry manometer and it's needs to react reliably measure within the tenth tenth of an inch of water column. That's that's where it needs to reliably measure and between 0.1 or 0.1 inches to about 15 inches of water column is sort of the sweet spot, because that's the range that we're gon na measure, with 15 inches of water column, sort of being our maximum input.

Pressure on an LP system, 0.1 inch of water column being the gradation that we want to see in static pressure, you know, did it go up or down point one beyond that? Do we really care you know? Do we really care for your static pressure? Went up a you know, a hundredth or something like that it doesn't. It doesn't matter that much for most of what we're measuring now when you get into a precision manometer, that's where, as we talked about the you're measuring and Pascal's and now you're measuring in tenths of Pascal's, and for most of our really fine residential zonal pressure and Balance or blurred or testing - that's where you would need something. You know like the retro Tec, manometer that's shown here, and so you there are some different grades and manometers for different for different jobs, and I am showing speeler saying that I'm you know showing some things that aren't filled. Peace yeah.

This is filled. Pieces is one product here that I that I love, but this is a training webinar. So I'm gon na show you a lot of different things and we've got a dwyer, wet manometer or you've got a retro tech, precision, manometer and then you've got the field piece utility technician grade, manometer which we're gon na be using day-in day-out Joe Matta asked me: If peach juice is a code word for wine, maybe that's my only answer to that all right anything! You want to add there Tony um. No, no, that's good others other than you still won't convince me.

That's not gin and juice, but that's fine, but yeah, fair enough, fair enough, all right! So let's talk about gas basics, and I, when I, whenever I talk about gas basics, you know it is more than just pressure. You do have to have a good quality manometer. It's necessary, in fact, it's it's really necessary to have a couple of them, and one really nice thing about these is that you can put them in different spots, which is super important, actually for a lot of the tests that we do being able to move them Around and find in order to find problems, but to start with, when we talk about gas first off first off, you have to be a licensed and well trained technician to do anything that we do, but especially on the gas side. So if there's anybody watching this who's like a DIY or a homeowner or something this is for professionals and even then follow your local standards codes all that stuff - and I'm not just saying this, because the lawyers told me to even though the lawyers did tell me To I'm telling you this because it's important that you follow best practices, so these are just some high points here, always verify safe levels of ambient co, carbon monoxide in the space and around the devices.

So for those of you who aren't using low level Co monitoring on your person, you need to start doing it. You need to make that part of your test to make sure that you don't have carbon monoxide either in the occupied space or around in that zone. A lot of people will talk about measuring carbon monoxide in the actual supply Airstream. That really doesn't work very well and there's a lot of reasons for it that I won't go into, but it's much more practical to measure low levels of carbon dioxide in the space.

Another thing is, and I would strongly recommend for those of you who work with gas to start recommending to your customers that they get a low level carbon monoxide monitor within their home, that below well below those UL required limits, because those UL required limits are gon. Na have them up in the thirty fifty parts-per-million before it even starts to alarm, and they could potentially already be getting quite sick. So i want to see devices that are going to show in the one two three four five parts per million when you could potentially have a venting problem or an issue with a gas appliance. So, first and foremost start there start looking at ambient CEO then do this normal best practices when you're testing appliances of checking for spillage? Again, that's checking for spillage around the appliance itself and then do the basic of looking at flame, color and flame displacement when the blower starts.

Those are old-school ways, but those are still very practical practices to follow. Now you get to the point of what you do with the manometer, which is set your manifold pressure to the manufacturer's specifications, and so a lot of people will talk about. There's this big dispute in our industry about under firing over firing all this stuff based on combustion analysis and i'm not gon na get into that discussion. What i will tell you is that you do.

You should probably start with what the manufacturer says right in the middle of their range and then, if you're going to adjust, adjust within their manufactured allowed ranges. That's the only place i'm going to land on that topic again, a lot of lot of discussion about that. Let me see if there's any and no questions, I want to address right now, it's next after you do that. That's when you would verify and correct input clock, the meter makes them adjustable and make some fine adjustments within the manufacturer's specifications.

Whatever the manufacturer says goes when it comes to this sort of thing, then do combustion test verify adequate draft, which is something you can do with the manometer generally, you would just do it with you or combustion analyzer. You verify acceptable. Temperature rise verify maximum combustion air zone. Depressurization is then allowable limits, meaning making sure that you're not depressurizing.

The the cast own too much that you could start back drafting and then try to achieve below 100 parts per million. Carbon dioxide, air free in the flue, which a lot of people will site 300. But we say try to get under 100 because in almost every circumstance you can the gas. The manometer plays part in steps 3 & 5, which are critical steps in this process.

But they are only a part of the process and I want to. I want to reiterate that, because first off, you've got to have a good manometer that you use, but second off just setting your gas pressure to the middle of that range and leaving that isn't a safe practice as it relates to working with gas furnaces and again. Having worked for years with gas furnaces, I know that that that I know what most technicians do, and I know that what most Texans do isn't enough, because I was one of those technicians and I'm still improving my practices, because I work and live in Florida place. So we don't have that much gas, and so we're all trying to you know we're like a hundred years behind everyone in Florida anyway.

So we're learning all these things. But as you start to test this, you learn that that there's a lot of a lot of factors there, I'm Steve Rogers. My good buddy Steve mentions that a precision manometer is good to measure the pressure in the combustion appliance on it can give you an indication of the risk of back drafting the appliances, and that is true, anytime you're, measuring very small, zonal pressure and balances. That's where a precision manometer can come in really handy and you're, not gon na use a precision manometer for measuring gas pressures, that's the job of a quality.

You know utility technician great manometer, but having access to a good precision manometer, I don't want to make it sound like that's, not a important or a good idea. It's just a it is a. It is a more precise tool and it has specific applications, which is a little different all right anything you want to add to that Tony. That's, a pretty comprehensive list, good job on that.

Alright, thanks, hey appreciate it. If all you do all day is just tell me that I'm doing a good job, I'm happy with that. Okay, I'm feeling good about myself. Alright gas pressure measurement.

So, let's go through the process of measuring gas pressure, so step one shut off the gas, because when you access the port's in order to attach your manometer, you need to make sure the gas is shut off. You don't want to have gas spillage all over the place, pretty obvious, but something you got to do, connect to the inlet and the manifold port. So my suggestion would be you know again: first zero. It out.

I didn't say that again, but we've already covered that four zero it out and then with this particular manometer you would connect one manometer to the inlet. You would connect the other to the manifold side, so that would be. The outlet of the gas valve then run the appliance in all modes and test, which means that if you have a multi-stage of clients to test it in the multiple stages and check your gas pressure, high fire low fire and make sure everything is set within those Manufacturers owns then make any adjustments you're going to make within the manufacturer's allowable range, once you've done. That and you've confirmed that the appliance is safe.

That's when you would shut the gas back off, make sure to reinstall the plugs upon completion. That is one thing that terrifies me. There's anything keeps me up at night. It's that it's this whole idea, generally speaking of, do no harm when we service equipment.

So when technicians are testing anything, and especially when you're working with gas, you have to completely commit to putting those plugs back in place, so put them in a location that you absolutely will never ever forget a good idea, which is just a good general practice for Anything that you cannot forget is take your van keys and put them together with those ports. That way, you cannot leave the site until you've had to interact with your keys and those ports. It's always a good idea to do that. It's in the same category, I use it as an example of strapping your ladders before you leave right.

Every technician knows that if you don't strap down your ladders before you leave, you could kill somebody and what happens is they get distracted and then they they put? The ladders up and they're, like oh I'll, strap them down later and then they forget they walk away. You never want to do that. Always make sure that the moment that you detach that you're immediately putting those plugs back in and you're taking all necessary precautions to make sure that you put them back in. Let's see here, Jason says: don't forget to reference combustion chamber in sealed combustion, high efficiency appliances, yeah good point, Jason again, I'm coming from a world and we're where we don't have that much high-efficiency gas, which is silly because so much of the world is high-efficiency gas.

Now, yeah, absolutely it's the combustion chamber that matters in the case of a high-efficiency appliance, and that is a really key thing reference to that combustion chamber in those appliances. So you need to make sure that you're reassembling it in a sealed combustion application and the applications that we work in with unsealed combustion, its unsealed. So it's the same as the room that you're in, but there is going to be a differential of pressure within that. Yes, so thank you so much Jason for mentioning that.

It's a very good suggestion. I'm Steve says I live in 80 % land and that is true. We're 80 percent saying 80 percent a lot of things. Just Google Florida man all right so just here here - are just some basic typical and I'm not even going to bother going through these in depth, but just some basic typical ranges that you're gon na see every technician should have these memorized, especially for your for your You know standard kind of single stage, operation three and a half inches of water column is going to be typical manifold pressure for natural gas, with Inlet pressure being 5 to 7 inches of water column.

Lp is going to be 11 to 14 Inlet and then 10. On the on the outlet, when this says setting range again, this is actually from the manufacturer specifications. This is from a carrier chart. So this applies to a particular model when I'm putting this up here for you to look at I'm using this as a reference of typical naught of something for you to follow to say well, hey Brian said I can set it in between 2.5 and 3.5.

This was for a specific piece of equipment, they're, just kind of giving you something to to look at here, always look at the manufacturers guidelines, as we say, RTFM, which means read the fantastic manual, not what you were thinking, Inlet and outlet pressure simultaneously is a really Good practice, what I see people do sometimes is they will measure your their inlet pressure without the appliance running and on in order to really test an appliance. Well, you need to be running all of the gas appliances in the house that are on that same gas supply, because that's the period of time when you're gon na have your maximum pressure drop and that's where it's most likely that you're going to have a drop In your inlet pressure below the allowable zone and if the furnace isn't running or if the device isn't running, I keep saying furnace, but it could be a boiler. It could be anything it could be a water heater or whatever. It is that you want to measure on if that appliance, isn't running you're not going to have that maximum pressure drop and if the other appliances aren't running you're not going to have maximum pressure drop.

I'm not saying you're gon na do that every time, but from a very practical standpoint, if you are running into an application where you have appliance that's, you know occasionally having issues maybe you're having rollout, but it's only occasion or only on occasion or something like that. You were going to want to test that and see. Are we seeing inlet pressure drop when multiple appliances are running and the location same thing is true, with voltage drop right, you don't measure voltage on a device when it's off when it's when it has no load on it, because you're all of course, you're gon na See proper voltage under those conditions, you need to measure it with it actually running same thing: you do the water pressure right. You can't measure water pressure at your house when nothing's on you have to measure water pressure when you are using water, otherwise, you're not gon na see that pressure drop and the same thing is true with gas, which is why i measuring inlet and outlet simultaneously.

It's really helpful. You can see whether your inlet is fluctuating down, but it goes too high fire, something like that. So, just a good general practice to follow yeah, one of one of the really nice things about the design of the new jelly phenom être, especially in this type of application. When you're, when you're measuring inputs that are so close together that because of the dual single port design of them, you can have very, very short, hoses and then attach the manometer exactly to where you want to put them without having to deal with like 6-foot hoses.

On an application where you're really only three or two inches apart from each other, so it's a it's a really good nice to have in those type of applications. Yeah, and that's something, and one thing that I want to mention: cuz, Michael. How should dressed this is that, when you're working in a high-efficiency application is something I should have put in this presentation and I'll do I'll, do a tech tip on it. Maybe Michael and I will will team up and do a tech tip or a video on this.

But you do need to make sure that you are measuring inside the actual combustion chamber, like, like Jason, said and Joe confirmed, and that can be a little bit tricky because again, you've got to put it back together before you can measure, and so you need to You need to zero it out, while it's in that chamber now, there's probably not gon na be a lot of fluctuation, so you could put it together run. It then zero it and then connect it, and so there's a couple different ways. You could do it or use an additional manometer, or only do it one at a time. You know, do your inlet and then your outlet and use the other one as a reference and there's a couple different ways.

You could do that, but it is. It is a good point and definitely something that we need to do a little bit more training on just to make sure nobody misses that and we'll work on that all right. So let's talk about a typical gas pressure adjustment. Now a lot of you are old pros and you're gon na be like oh, my gosh.

This is the world's most boring thing. We do this all the time. Why are you showing this? Because it's important there's a lot of people who don't know this, and so it's important to cover it quickly. We're not gon na spend a lot of time on it.

The first thing that I see newbies do when you tell them about the pressure adjustment, is they think that the cap on the outside is actually the adjustment? And it is not. The adjustment is underneath this cap, so you have to remove the cap and then you make your adjustment and obviously, when you make your adjustment, it's going to change the pressure of the outlet and so it's clockwise to increase pressures. So I always say you know it's similar to your your torches. You know setting your oxygen on your torturous oxygen pressure.

Just like that, so you turn it clockwise. You increase your pressure, counterclockwise, you decrease your pressure and that's the standard way that it's been done for years, but then we also have the Gemini version and there's multiple brands that use this. It seems to be a white rogers thing. I don't know if there anybody other than what Rogers does this, but when you have the the Gemini type and it's actually, you know it's actually a pretty pretty easy way of doing it.

You do have to have a different adapter in order to in order to make the connection, and you actually very simply have the pieces. I wasn't going to show it here, but let me see if I have them. We've got a picture here, but they come with them in the field piece kit and makes it really easy to adapt the 5/16 that it slides over to that Gemini port type to the 3/16. Just to make it more clear of what you've got here.

I'm gon na show you this quick, quick video and so you've literally placed the 5/16 over this port after you crack it open. So you shut the gas valve off you crack it open. Then you place the port over the same place, that you made the adjustment or I'm sorry that you that you backed it off cracked it open slightly, and then you make your adjustment like you normally would. But you do need to make sure that you do not back this out all the way you literally just crack it open, and then the gas pressure leaks around.

That's that little screw. So I'm pretty simple stuff, but one nice thing about this kit is: it does come with the barbed fitting and then the additional adapters. It comes with two different hose sizes: three sixteenths and five sixteenths that you need. I think it is three sixteenths and five sixteenths right.

I think so. Yeah sounds right. Yes, that's correct sounds right. Alright, anything you want to add to any of this Tony today.

Am i covering it? Ok, anything I missed no yeah. You covered the point that I wanted to make that there were a few questions as far as what type of fittings come with the actual job link pros, but yeah, so they come with the standard. You know brass brass, fitting that you saw previously. You know they come with the 5/16 inch adapter tube and barbed metal tips on the actual tool themselves and then also when you get into static pressure, you you know they come with a couple of static pressure, probes as well.

Yep, there's there's a static pressure probes and they actually come right out of the box. Preassembled like this, which is kind of cool for dummies. Like me, alright Tina's making fun of me because I made fun of her for saying yes know, one time and now she's saying no yeah, because I say I said no yeah or maybe it was Tony who said no yeah, not sure it is the thing people Say: listen out, for it michael says their 8-inch male pipe thread, and that is the that is this part here. So this this is the eighth inch male pipe thread part, and it does come with that as well, and then it has the the Barban right.

It doesn't matter actually what size tubing you're using, but anyway, these come with all the parts and pieces that you're typically going to need either for the standard of the Gemini valves. Alright, so that's it about gas pressure and intestine gas furnaces again. Remember as we go through this, it's always important that you're that you're thinking about your manometers in terms of what are you measuring it's differential pressure, so you've zeroed it to something and now you're you're referencing it to something you're, referencing it to what you zeroed or You're referencing them to each other, and that's a nice thing about these probes - is that you do both. So you can reference each one individually to whatever pressure you use your owed to, and you can also reference them to each other, which gives you sort of that.

Additional reference, so you're, not only referencing to the other that was sort of the old-school way was when you had p1 and p2, they were always only referencing to each other, whereas now you have this one, that's referencing to each other, but also to atmosphere. The other ones referencing to each other, but also to atmosphere or whatever you zero. It doesn't necessarily have to be atmosphere. Somebody said that my screen so small, I tried mirroring my screen to TV, but it won't - and I don't I don't know why my screen is so small.

Sorry, some of these technical things. You know you just got to roll with what is static pressure, static pressure is a force exerted in all direction, so it's different than velocity pressure. So when you see this picture, when you see the image here and the air is flowing past the static pressure probes, it is not measuring the force of the air pressure directionally. It's measuring the air pressure, that's going in all directions, and so it's similar to atmospheric pressure.

The atmospheric pressure 14.7 pounds per square inch that atmospheric pressure is pressing down on us in all direction. Equally, it's not like it's just pressing down the top of our head right is pushing at all angles and in all directions and that's what static pressure is one way of thinking of static pressure. Is it's like balloon pressure when you blow up a balloon? It's not that the pressure is going only one direction, it's filling up and it's pushing against all sides and that's why a balloon inflates into a circle, because it's it's that forces applied in all directions. It can be positive or negative in a reference to the atmosphere or anything else.

So when we measure something we say it's a negative pressure, we're saying it's a negative pressure compared to something right: it's not really a negative pressure, because there's really no such thing as negative pressure. Everything is positive pressure or less than some other positive pressure. So generally, when we say negative pressure, we're saying something: that's below 14.7 PSI, a which is our you know, sea level, atmospheric pressure, and so it seems negative because the air, or whatever fluid we're, dealing with moves in that direction. But the reality is: is that the lowest pressure you can go is 0.

We say negative pressure, we're saying negative in reference to something and that's why a manometer will measure in a negative pressure, which is why, from a very practical standpoint, we will hook one of these manometers up and we'll put it in the returned and it will measure Our negative pressure, it's negative compared to the atmosphere because there's lower pressure and the return than there is in the closet or garage or attic or ever you're standing and to the other probe that you put in the supply or some other location. And that's and that's practically what you're doing with a manometer is always measuring a static pressure or always measuring a pressure differential from one to another and specifically how we use them as technicians and the air stream is mostly to measure this static pressure. You're not measuring again directional force you're measuring the pressure inside the duct Ken says: there's no such thing as negative pressure, there's no such thing as negative pressure, because what what's a good way of explaining this when you, when you go down into the ocean right, you Know that that pressure builds and builds and builds as the deeper you go into the ocean right, but what water pressure is there when you are right at the surface of the ocean? Well, there's water pressure, but you can't go negative water pressure. You just go out of the water right and it's the same thing.

It's true with our atmosphere. You can have close to zero air pressure. That would be space, but you can't go less than zero air pressure. You can go less than something else, and so, if you compared the water pressure a thousand feet deep to the water pressure 500 feet deep, you could say that the water pressure 500 feet deep is negative in comparison to that deeper pressure, because there of that differential One question that and we'll cover this, but one question that is asked is: why is it important to direct the probe into the air flow and actually I've done a lot of tests on this Tony can feel free to dispute this if he wants.

This is a moment for you to argue with me Tony that with the air flow, then I agree with you. Okay, yes, and so it doesn't matter much as long as it's in parallel with the air flow. The reality is, is that this tip, even you could cut it off and if it came into the duct and was just in the duct and was perfectly straight even that would make very little difference on a residential system. The higher the air velocity.

The more of the positioning matters so on a residential system, a lot of people like my buddy Neil competi, as used a ball needle in certain residential systems, where it's hard to get the full-sized probe in and it works very close. Is it as accurate? No, it's not on residential systems, though we have pretty low air velocities and the reason why to answer the question, because sorry, for my little my little monologue, I went off on there. The reason why you want to insert it parallel to the air flow is that you want to measure static pressure, the pressure in all directions in not the velocity pressure. If I took this end off - and I pointed this open end into the duct, what would happen is is, I would be measuring velocity pressure, which is the directional force and we're trying to ensure that we don't measure that directional force.

So, from a very practical standpoint, just imagine this air hitting this tip and dispersing around and it prevents velocity air via turbulence or whatever from make into these holes just makes it a more accurate measurement so again, typical residential equipment. If you point it with the direction of air or against the direction of air, it's gon na make very little difference if you put it in sideways, that's where you're gon na start reading incorrectly or you know any sort of other direction, but many will tell you A ball needle works fine or the old probes that used to just stick straight in on low air velocity that we should be seeing unrest attention. If you have high air velocity, that's a sign. You also have high static pressure, different story again on typical residential air conditioning system.

I've got Steve here and Steve is gon na correct, so many things that I say here because he's like the air measurement guy, but anyway, moving on all right static pressure, probes versus pitot tubes - and this is actually what we were just talking about here. So a lot of people will call a static pressure probe a pitot tube and it is not a pitot tube. It is not a pitot, you know, drop the tube, it's not a pitot. A pitot has a tube in a tube and it has a separate 90 degree port.

That's for the purpose of measuring static pressure, so you could use a pitot and measure just static pressure by only connecting to the side port on a pitot. But that would be silly because it's a much more expensive tool and usually they're much larger and more gangly. And cumbersome, so why would you use that and then you have a total pressure connection which is fed from the end, so that takes in the pressure going from the end, which gives you velocity pressure and the static pressure together. Then, when you subtract the static pressure from that total pressure, that gives you just velocity pressure.

So the point is: is that using a pitot tube is for the purpose of being able to actually calculate velocity pressure, which you can then use in order to calculate air velocity, which you can then use in order to calculate CFM right and a lot of people? Will say well great: why don't we use this? Because it's not practical for residential applications? It can be done with a precision manometer, but it's still not a practical way to do it in residential systems and residential systems. There's other better ways to measure air flow. Using a pitot tube has applications commercial, Industrial contaminated air streams, high-velocity air streams, there's plenty of commercial applications where a pitot tube might make sense, and in fact, when you get into high velocity air streams, you could even use this manometer. As long as the velocity is high enough, because again, if you think of it as the old, the best example I've got, is you remember, we were taught to amplify the signal when we're setting a heat anticipator, I'm totally changing topics here, but when you set a Heat anticipator on an old thermostat.

You would wrap it ten times in order to measure the currents, because that way, it would give your meter the accuracy needed in order to measure that it's the same sort of thing in residential air streams. We don't have that.