Steve Rogers and Chris Hughes with The Energy Conservatory (TEC) talk to the Kalos techs about airflow measurements. They also explain how to use the TrueFlow grid and app to help with commissioning.
Airflow is important because we need it to be accurate to charge refrigerant properly, it’s crucial to homeowner comfort, and it can affect system efficiency.
When the airflow is too low, less heat can be absorbed in the evaporator coil, which drops the pressure in the coil and decreases the refrigerant density. The compressor can’t move as much refrigerant if the airflow is too low. You won’t get proper air mixing, which makes it difficult for air to circulate comfortably for the customer.
If the airflow is too high, the efficiency is good, but you can also get noisy ducts, reduce dehumidification, and run high suction pressure. High airflow is also uncomfortable for a lot of people, as they don’t want to feel air blowing on them forcefully.
The TrueFlow app has four workflows: system airflow & static pressure, system airflow, blower fan airflow grade per ANSI/ACCA/RESNET Standard 310, and pressure gauge. Most A/C technicians can meet their needs by selecting system airflow & static pressure because you will get both of those critical values on the diagnostic screen. The system airflow is a fast workflow, but you won’t get the thorough breakdown you’d normally get on the first option. The RESNET 310 Standard is mostly for inspectors to check the target airflow. Finally, the pressure gauge allows you to take and record static pressure readings.
You can connect the pressure gauge and TrueFlow plate to your mobile phone via Bluetooth. Then, you choose if you’re dealing with an air handler or furnace. You then select the airflow orientation and enter the cooling capacity, air filter location, and cooling climate. After you input the relevant information, you’ll receive a set of test instructions. During the test, your tools take 100 readings and give you an average value on the TrueFlow app.
The TrueFlow grid replaces the filter during testing and takes readings where the filter normally is. It measures the airflow by taking a measurement similar to a duct traverse. With the filter in place, our test measured 563 CFM. A lot of math happens on the back end; the TrueFlow grid and app use a correction factor to predict what the CFM would have been with the filter in place.
The diagnostic screen shows whether you have good, okay, or bad airflow and static pressure, and it shows potential problem areas that it has identified with the A/C system. It also shows the return static pressure drop and the supply static pressure. In our case, we had a very high supply static pressure. Overall, both airflow and static pressure were okay, with the former being a bit low and the latter being a bit high.
In some cases, the static pressure and airflow issues may occur due to poor duct design. In our case, the TrueFlow app recommended checking to see if the supply duct is undersized, collapsed, or restricted.
If a homeowner wants a copy of the results, we can send them the results and send pictures of the equipment through the TrueFlow app. The app automatically generates a PDF that you can send to the customer.
The TrueFlow grid comes with an adapter plate that can help the grid fit in oddly sized systems. TEC has also been considering custom sizing options. However, when selecting a TrueFlow grid, the most important thing is that it measures the total airflow through the grid. The TrueFlow grid works regardless of the equipment’s cleanliness, but TEC doesn’t recommend doing static pressure tests with dirty equipment.
In our second test on a different set of equipment, the TrueFlow grid picked up 687 CFM. Overall, the airflow and static pressure were both in the optimal range. However, if we wanted to improve a little bit, we could have addressed the somewhat high supply static pressure.
Read all the tech tips, take the quizzes, and find our handy calculators at https://www.hvacrschool.com/.
Learn more about the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.
Airflow is important because we need it to be accurate to charge refrigerant properly, it’s crucial to homeowner comfort, and it can affect system efficiency.
When the airflow is too low, less heat can be absorbed in the evaporator coil, which drops the pressure in the coil and decreases the refrigerant density. The compressor can’t move as much refrigerant if the airflow is too low. You won’t get proper air mixing, which makes it difficult for air to circulate comfortably for the customer.
If the airflow is too high, the efficiency is good, but you can also get noisy ducts, reduce dehumidification, and run high suction pressure. High airflow is also uncomfortable for a lot of people, as they don’t want to feel air blowing on them forcefully.
The TrueFlow app has four workflows: system airflow & static pressure, system airflow, blower fan airflow grade per ANSI/ACCA/RESNET Standard 310, and pressure gauge. Most A/C technicians can meet their needs by selecting system airflow & static pressure because you will get both of those critical values on the diagnostic screen. The system airflow is a fast workflow, but you won’t get the thorough breakdown you’d normally get on the first option. The RESNET 310 Standard is mostly for inspectors to check the target airflow. Finally, the pressure gauge allows you to take and record static pressure readings.
You can connect the pressure gauge and TrueFlow plate to your mobile phone via Bluetooth. Then, you choose if you’re dealing with an air handler or furnace. You then select the airflow orientation and enter the cooling capacity, air filter location, and cooling climate. After you input the relevant information, you’ll receive a set of test instructions. During the test, your tools take 100 readings and give you an average value on the TrueFlow app.
The TrueFlow grid replaces the filter during testing and takes readings where the filter normally is. It measures the airflow by taking a measurement similar to a duct traverse. With the filter in place, our test measured 563 CFM. A lot of math happens on the back end; the TrueFlow grid and app use a correction factor to predict what the CFM would have been with the filter in place.
The diagnostic screen shows whether you have good, okay, or bad airflow and static pressure, and it shows potential problem areas that it has identified with the A/C system. It also shows the return static pressure drop and the supply static pressure. In our case, we had a very high supply static pressure. Overall, both airflow and static pressure were okay, with the former being a bit low and the latter being a bit high.
In some cases, the static pressure and airflow issues may occur due to poor duct design. In our case, the TrueFlow app recommended checking to see if the supply duct is undersized, collapsed, or restricted.
If a homeowner wants a copy of the results, we can send them the results and send pictures of the equipment through the TrueFlow app. The app automatically generates a PDF that you can send to the customer.
The TrueFlow grid comes with an adapter plate that can help the grid fit in oddly sized systems. TEC has also been considering custom sizing options. However, when selecting a TrueFlow grid, the most important thing is that it measures the total airflow through the grid. The TrueFlow grid works regardless of the equipment’s cleanliness, but TEC doesn’t recommend doing static pressure tests with dirty equipment.
In our second test on a different set of equipment, the TrueFlow grid picked up 687 CFM. Overall, the airflow and static pressure were both in the optimal range. However, if we wanted to improve a little bit, we could have addressed the somewhat high supply static pressure.
Read all the tech tips, take the quizzes, and find our handy calculators at https://www.hvacrschool.com/.
Learn more about the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.
So we're happy to be here um, we're hoping that this will be a little different than a usual training with you guys. We actually want this to be kind of collaborative. We know that a lot of the people at kayla's have a lot of experience um to share with us we're still learning exactly what are the best ways to use this product in the field, and so we want you to get your hands on the app once You get your hands on the hardware and talk to us about how this would be useful. What problems you can envision solving with this.
We want to hear feedback. You know after we're gone, i know. Brian's uh got three systems already and we want to hear how you're using them - and hopefully this is. This - is a two-way street.
We're learning as much from you are as we are teaching you, i would say in y'all's climate, i'm sure you all come across every now and then an air handler in specific times of the year, where that coal is really making a lot of water. There's a lot of sweat right and it's problematic and then as technicians as we grow understanding of airflow and superheat and sub cool, and all of that we can sometimes mitigate some of these problems in certain situations. But airflow is it's a challenging one to understand. Total external static can work um.
It is a pressure measurement, not a flow measurement right. We use it to correlate to flow through to a chart, but sometimes that could be misleading if the indoor coal gets dirty, the blower gets dirty right. It's going to mislead us and it's not going to be truthful, so as technicians and we're understanding, airflow more and more and more. What we're trying to explain is this tool is going to like get you over that hurdle to where you feel 100, confident to where you can now talk to the homeowner about that problem with pure confidence, and it's no longer like i'm 99.
We want you like 110 to where you can say. I know this and now i've i'm backed up by something and there's a report. You can give them and that's really. The idea is like we want to raise the bar in the industry about air flow and make it important commissioning is always been something that gets pushed to the wayside right.
But it's probably one of the most important things we should be doing and it's hard to get to it right. It's at the end of the day, you're beat down tired, and last thing you want to do is dial the system in, but we dial that system in callback's being reduced. It's a good tool for system checks to leave that place with a clean slate thumbs up. Homeowners happy they have a copy, you have a copy, our bases are covered right and that's what we're going for raise the elevation of airflow knowledge in the trade.
So i want to start. I know i've heard brian talk about this, but i want to ask you guys: why does airflow matter with an air conditioning system? It is the driving force. What do you mean by it's the driving force without proper airflow you're, not going to get proper measurements in any part of the system, so you're not going to get any, including what are the ones that you're not going to get yeah refrigerant, uh readings you're, not Going to get even mechanical certain applications, especially and you you're not going to get the correct charge if you don't have correct airflow right the super heat and sub cooler affected by airflow. What else comfort tell me what you mean by that the air um is too low: it's not moving the heating fully as efficient as efficiently. If it's too high, it can be uncomfortable, so we're getting into two different things if it's too high and if it's too low - and you mentioned two things - comfort and efficiency - let's try and put those together if the airflow is too low. What does that do to our efficiency? Anybody know? Okay, so if it's too low you get are better with three t's. Okay, anybody know what happens to efficiency. If air flow is too low yep, it gets worse so quickly, because we've talked about a lot of this.
Lately, what happens, why does efficiency go down when air flow goes down? I just want to tie these ideas together. What happens to your evaporator coil, when the air flow over the evaporators are specifically talking indoor airflow? What happens inside that? Evaporator coil, it's colder, there's less heat being absorbed into it right, and so it gets colder. What does that do to the pressure in the evaporator coil drops the pressure on the evaporator right, which what does that do to the weight or density of the refrigerant? Returning to the compressor, what's that decreases it right pressure is less. That makes the return gas lighter when the return of gas is lighter.
What does that do to the compressor? Well, the compressor can run hotter, but also you're not moving as much refrigerant, so every stroke or oscillation of that compressor, less refrigerants moving when you're moving less refrigerant. What does that do to your efficiency decreases it. So i just want you to think all the way down the line of why that's decreasing efficiency, because the air gets colder coming out of the top. We have low airflow right.
We get cold air coming out of the top, because the air moving over that coil is moving slower and that evaporator coil is colder right. So sometimes we think well colder air. That means better efficiency right, but it's less air colder air, lower, evaporator temperature, lower suction gas pressure, lighter suction gas equals moving less refrigerant, which means less efficiency, and so what happens to capacity. So this is very much related.
Efficiency goes down right. There flow is too high yep higher suction pressure, yeah uh yeah, okay, duck noise. What about efficiency decreases? Huh decreases. Nope efficiency is great.
In fact, if you're in a dry climate, if you're in arizona, you want to run 500 cfm per ton, okay, it is actually an interesting there's, an interesting thing that happens here, though, in our climate, which is that there's a point at which you run air flow. So high that you're uh, that even your capacity crashes yeah, because total capacity is a combination of which two types of of cooling, latent and sensible right. So when you hit the point that your evaporator coil is near or above dew point so now, you no longer are doing any latent cooling. Your system capacity will actually crash in terms of overall system capacity in a market like arizona where you have no chance at dehumidifying anyway, because the air is so dry and the dew points are so high, i mean so low, yeah so low. In that case, you run the airflow up intentionally, because all you're really going to do is sensible and that's all you want to do anyway. Right, you don't want it further to humidify the air when it's already dry, but in our market. Getting that coil to the right temperature is what optimizes our capacity, our efficiency and dehumidification keep going. So what happens to capacity if airflow is too high increase yep, so capacity goes uphill increases yeah.
I thought about this one, but duck noise can be a big problem. Uh, our friend ed john, walk, always talks about when you have to turn the tv up when the air conditioner comes on. These are really good answers. Any other uh answers to why we care about airflow.
What's that big from the whole system yeah, if you're, only looking at the refrigerant side, you're only looking at half the system, it's the other half yeah, they call it air conditioning for a reason. There's one more thing: we're not thinking about in terms of customer comfort, though with airflow, so we've talked about. If it's, if it's not low enough, you won't dehumidify right. So we need to get the right amount.
We don't want it to be too high. But what happens if it is too low to customer comfort right so you're not going to get proper air mixing? If you have a system, that's designed for a particular airflow you're not going to get proper air mixing. If you don't have proper uh discharge, the velocity. That's another one too yeah, that's another, really big one uh undesigned condensation, so condensation, sweating, ducts, sweating equipment.
All of that airflow is too low yeah, so your duct temperature can actually get colder than you want it. Now you got water, condensing where you don't want it and you got mold so i'll. Ask a question: can you set the super heat and sub cooling on a system in this climate at 450 cfm's per ton, so you can set the charge with an improper airflow, but let's say that house needs 350 cfm's per ton. What should come? First, setting the airflow or setting the charge abc air flow before charge right, airflow right air flow then set the charge that way you're trying to achieve the right dehumidification in that home.
How do we measure airflow? That's what we're trying to find out exactly perfect before we showed up. How did you measure airflow? You called max yeah. You call max so we're going to get your hands on stuff. Now, that's a perfect intro! That's what the app looks like right, open the app when you open the app. These are the four workflows that are available i'll, just kind of generally talk to all you guys about what the workflows are. So the first workflow system, airflow and static pressures as an ac technician, i would say: that's the workflow you're looking for because you're going to get system air flow in the diagnostic screen and you're going to get pressures in the diagnostic screen and you're going to get A breakdown to show you where the problems could be now the unit is set up with a problem right. So when we get to the diagnostic screen, it's gon na we're gon na hit the detail screen and say: oh what's going on here interesting, so the second workflow is system airflow. It's like a quick in and out right.
Let's just say somebody just wants system airflow and they don't want the pressures. That's a very fast workflow. You won't get the pressure screens right or the breakdown you have the resnet 310 standard workflow, that's for your hers, raiders and people who are grading homes. What they're going to do is enter a target airflow.
Let's say you did manual j dns on a house right and you've designed it, and you have a target where you want to reach and the house is going to get graded for that standard 310. During that workflow, you would enter your target, airflow run the test, and then the test is going to grade itself. The grading platform for uh, resnet, 310 and aka 310 is in there right and it's going to tell you if you pass or fail. Basically, right he's graded one two or three and then there's a pressure gauge.
If you just want to take pressure reading record, it does pressure right, static pressure, so we're going to do system airflow static pressure. Okay, now, you'll have oh see. We got steve devices over there, so we have steve he's firing up his dg8 and his true flow grid, i'm not sure which two he's connected to. So we need to connect to r2 right.
Normally. You're not gon na see this in the field, because you're not gon na have two right. You're gon na have one on your truck, so you'll see there's a model number dg8507, nice right so that you know that's the one you want to connect to so hit. The plus the bluetooth's like proprietary to tec, so you don't have to go in settings and find it.
You open up the tool you hit, plus it syncs up automatically. What's the bluetooth range on this chris uh, it varies right because you could deal with. Uh depends on what type of building you're in yeah we've had guys that went all the way across the house: two-story houses and it works, but uh it's good. You know, bluetooth is a variable entity, so we've got truflow grid 112.. So let's hit the plus there. Okay: okay, we're connected to the two devices now on this screen. It's telling you two big buttons right. Is it a furnace? Is it an air hound which we have an air handle, so you just anywhere on that screen bam flow, horizontal downflow! Oh sorry, are you you're good to that? That's what oh, we don't have a down flow, you're right! Sorry, it's my first day.
This is how easy it is so cooling capacity. This is a two ton on the condenser right. Condenser capacity is two times so click the two. Do we do that in btus, or do we just no just two, just just two: okay, easy yep air filter location? Is this a little tricky because it's a test model unit? Normally, this would have duct work coming off of it right so yeah being it doesn't we're going to treat it as a filter, grill, okay.
So what if you have certain systems like that sitting in closets that have a return grille in the door, but there's no actual ductwork, because it's just sit through the middle of the house. You would do filter in slot because there will be. There would be a little bit of pressure inside that chase. It ain't much of a chase.
It's just a box right, but there's a grill and grill is a resistance, so you're going to have a little bit of pressure there and you want to account for that. So you go filter and slot so cooling, climate, humid, humid, climate, so 350 and then click next. There you go so that's test instructions. You'll have some systems depending on the climate zone where they may have uh some air.
That's going through a different system, a humidifier. Maybe, as a bypass loop right, you'd want to valve that out. So there's no bypass airflow running the test, so we don't have that. So click continue.
Okay, this screen gets you started right. It gives you a picture of the install and it shows you exactly where to put that program i'll. Let you see the workflow i'll place, the probe for you. So you know what's going on so we're going to put that in between the filter and the coil right.
So we've placed our static pressure probe. We've got our reading, we'll click take measurement so every second. It takes 20 readings. It's a five second average.
So we get 100 readings and then we average those readings. Okay and now it went from return duck to supply duct. So it's telling it's prompting us to take the static pressure out, attack the pressure probe out and install it in the supply plenum. Now, if you had two of these test tubes, could you just pull the hose off the manometer and yeah, or just like or yeah just have one in the return one in the supply? Or do you have to do it each you have to move it.
Click. Take measurement okay right there we go we're taking our average again. Okay, so we've captured the readings in normal system operation with the filter. Okay, and what we want to know is we want to know the flow of this system right now with the filter in it. Okay, that's what we're going to get later, so we got one more step. We'll click continue. It tells us take the filter out, put the digital, true flow grid in place of it. I always rip those when i take them out.
I don't know how i just did that you'll notice. It says air in right there, so it tells you but here's. Let me show you something. Don't click take measurement yet watch what happens when i put it in upside down? Okay, so let's say we're in a rush and we're like you know what i'm just tossing this thing in get the flop.
So when the airflow's blowing backwards, it'll tell you check true floor plate orientation, nice. So you can't miss the mark right and even if you click take measurement, it won't give you a measurement it'll just default to that screen awesome. So that's a preventative measurement. Okay, so remember! The idea here is to not let any air take a bypass loop.
We want all air moving through the grid so now that the grid's in place we're going to take measurement. We're going to take all those readings now what's happening is we're. Reading all the airflow across that grid we're taking like a traverse right measurement right there with a new static pressure with the grid in place. So there's our airflow 563 cfo, that's cool, that's the cfm with the filter in not what the grid in currently right.
There's a correction factor, that's happening in the app that's saying if this was the static pressure with the filter in this was the static pressure with the grid in and here's the flow with the grid. Here's the back end data coming at you to say here was the flow when the filter was in right. It's a lot of math going on on the back end. So if you click continue, you can save it internally into your phone or tablet and there's our diagnostic screen from that diagnostic screen.
We can see airflow, we can see it's in the yellow right and this is to be built as like training wheels right. Let's start with new system: okay, you've installed a new system, your ductwork may be okay, and this may be a guide to say, hey. Well, i need to increase the fan, speed on the unit or god forbid this happens. But let's say you do a system install somebody maybe didn't do a good job on the manual jds right or the manual d section of the job and the duct design was was not good and you got high supply static.
Everything right, not our installs right uh. We go check. Somebody's install you'll see that the supply static pressure is 0.8, which is crazy, high right. So our total external statics kind of say like right.
You need bigger dot right, so we need to relieve some pressure, so we can see it broken down here. Supply plumbing pressure right 0.7 - that's aggressive! That's an aggressive! You know, there's two things you kind of got to think about. This is why we built the chart where you have two main graphs: airflow external static pressure. Right those mean a lot to us as technicians, but if we built those margins too tight and we were always in the red, then homeowners would be mad at us when we started giving these reports right. So we had to play all brands right so think of it as like training wheels. So we opened the bands up a little bit to give you some rules to say hey depending on your unit, you're okay. But if you look down here, these are recommendations right to where it's like, hey under a typical install situation where supply static pressure should be 0.1, maybe 0.2 you're at 0.7 you're way out the box on what normal should be. We don't want to tell a homeowner like, oh my god, it failed because it's a rough conversation right.
It's like how do you go to a homeowner and say your duck works really bad right after the fact. But yet the system's been installed for two years and let's just say the climate wasn't right and they didn't it didn't cause sweat issues right and so you're there on year, three, not your install and then you're thinking yourself, man. I have this. This is really bad and let's say you didn't have this: how do you have that conversation with just external aesthetic pressure measurements you're going to be like man, your duck works, really bad and what's at home, we're going to think so guys, yeah sales guy you're telling Me my assistant's, been here for three years and all of a sudden, i have bad duck work problems get out of here right all the vents up in the house.
This is just a nice way to say it's not just me, you know a manufacturer who constantly studies airflow and puts all their effort to airflow. Knowledge is also standing with me and giving me this report that i can give to you to say you have bad dog work problems right, like here's, a obvious reason that we got to do something and then it you know it gives you the encouragement to maybe Say if we fix this, you won't have the chance of that happening to you right of system sweating out of control it because it's in a hot humid attic. In this situation we have a busted duct system right. The supply plenum's got a lot of pressure drop.
If you click the detail screen right here, it will tell you, you have low flow and you have high supply pressure right and it'll. Give you some recommendations of what to look for and what to attack. So you can debrief yourself before you go. Have that conversation with the homeowner that way? Not only do you know, there's a problem and now you're confident.
Now you can kind of get into executing some of the solution. Based conversation, you might have been 99 confident, but maybe now you're 110, confident because it's like hey we're tec, we're standing with you like we put enough faith in that tool to where we're we're telling you and we're standing right like we're in the house with you. We're standing with you and saying make a video right here and saying that so you can play it for the homeowner. Chris is standing right here with you. Yeah just crop me and put me right there and say: i'm i'm with you man, it's good! It's good! For business, let's say the homeowner wants a copy. Okay, we can go down here to the pdf button right here: click that we can enter the customer's information. We can also take pictures of the equipment, let's say the supply, pressure's really bad, and we can see why crush duct work. We could capture that picture, save it in that format.
So when we generate a report at the end, there's the report where you're going to have all the customers information you can put the company logo here right, your breakdowns. Are there all your pictures? Are there put your pictures for customers? Customers understand words right. I think technicians and i think homeowners are going to focus on those graphs. That's all right! That's where it's going to be and then, as you get more used to this program, what i see happening is techs are going to start looking at the numbers more and the graphs and start thinking well, this gave me bad numbers at 0.4.
This gave me bad numbers at 0.5 and then what we're trying to do is slowly train you to say, hey supply static pressure is best at this range return. Static pressure is best at this range right, just to kind of give you like a better understanding of what the static pressures should be throughout the whole system, all right who wants to rip and run all right, so we're going to close that we go back. We can just hit measure. It goes right back to the screen.
We can do it again. How can we spice this up a little differently? It's a super complicated application, so that alone is going to throw you for luke. Let's open the pressure up, let's see we're getting we'll see, i think, there's a damper on top too. You could open all the way up as well.
If you want yeah, i'm thinking, i want to get you somewhere, 0.4 prepping it just so i can kind of determine what the results are going to be. So you have two ports coming out of your probe here. Yes, what's the other four okay, give me one. Second, let me see if this is where i think it's going to be yeah, it's good.
You also know the filtering right now by the way. You still have that oh you're right so for this. Obviously you have to have multiple frames. We do.
We have seven frames and a uh custom built frame and we're making more frames for if somebody wanted a specific frame gotcha now, let's say you were to have a lot larger. One of these does this plate that goes in here. Yeah. Do you have different sizes of this? Was it just the same? Okay plate can move up to uh.
It can calculate up to 2 000 cfm's okay. So if you were to have like an 18 by 30, you still use the same plate. You can take the cut to fit adapter plate and make an 18 by 30 out of it every now and again, i see them right like the odd ball. Here's! What i'll tell you if you come across a situation where the adapter plate is not in your kit and you don't necessarily have to have an adapter plate. You could put in a kit that fits three sides and blink off the right side. The idea is just you got to move all the total system airflow through the plate, so you may have a situation where you're like oh man, i don't have the right adapter plate, but if you're creative and you have like a piece of cardboard or some masking Yeah you know pop it off get the flow. It's done. Okay, it also works in double return situations.
There's i made some videos on hvac airflow.com that shows how to use this. If you have two main returns right and what happens is that's soon to go into the workflow to where i'll show you how to do it? But before we got there, i made a video on how to show people, because it's brand new, we were people were asking yeah so right now, what's we're doing is we're putting the true flow grid in one at the point where it says put the grid in When you do that, you blink off the other grill that way you move all the system airflow through the grid and it's giving you the flow with the double filter return. So you can do it in a double filter, rotation, interesting and if you have that wouldn't restrict air flow at all, though, having one of those completely blanked off the correction factor, picks it up really. So it's just built into the system and the programming of it right, the correction factor.
So so here's a here's, something really important: we're not taking total external static pressure like a blower chart's being used right, we're not using the correct we're not using the static pressure for that reason, we're strictly using it for the correction factor right, yeah whatever it is Here, what is what's it here with the plate, and that just makes our shift right? It's just an equation, while total external static pressure or external static pressure and fan table they're using those measurements to correlate to the blower chart total separate game being played. It's like a math problem word problem when they go train takes point a to point b. It takes six hours. How fast is it going yeah over this many miles? It's just the same equation right.
The difference is we're actually measuring the air flow yeah, while when you're just taking pressures and then correlating to a fan, chart you're, just you're, just transferring pressure to flow but you're not actually measuring it. And here's where that's going to fail. If you're, in a situation where this indoor coal is dirty - and you try to do external static pressure and go to the chart, it's going to fail, you big time right and the more dirty the coal is, the more caked up. The blower is the more you're gon na fail. Here's the weird part about that. It's not gon na fail you a little bit because when the internal compart components get dirty, the pressures are gon na go down right and when you go to the fan table and the pressures go down, it's going to say, you're moving more airflow. So when you think you're going to just be off a little bit, you're actually going the opposite direction. Yeah you're going to be off a lot, so it would read a coil like that.
What's that so wouldn't read the coil, no yeah! The true flow will tell you the flow, no matter what's dirty, but you wouldn't want to do external static pressure tests with that coal, because it's going to fail you, but that's that's the idea. This is going to give you accuracy, no matter if it's dirty or clean it works for both there's good methods out there just got to know when to deploy. That method sounds like a lot of training wheels for airflow a lot of training wheels right. You get the diagnostic screen and the more you look at it, the more you're going to train your brain to start thinking.
You know this is good, that's bad, and even if one day you don't have the program with you, you put you pick out your monomer and you go bam and you're training yourself to go. I know that's bad because when i had my true flow on a job like this, it told me that was bad right, you're, gon na start, remembering those numbers and get more comfortable with static pressures and what should be normal through the duct system system. Airflow static pressure, starting there we have an air handler air handler electric heat with a up flow application and then cooling capacity. She's asking for the tonnage of the system system is a on the condenser.
It's a condenser over there, it's a two-time, two-ton and then air filter location, we're doing the filter grill for we are because we don't have any return. Duct work on this one. If we did we'd call it a filter slot right because we're not going to have any pressure resistance below that filter, all right, filter, grill, okay and then cooling climate. We have a humid climate here.
You can feel it in the air close any humidification dampers set the equipment to cooling mode at a high speed temperature, so we're good to go. Just press continue good to go, and then it's asking for our redurn talk. Return duck static, then i should be able to come here and that connects straight to that and you said it measures for five seconds and it's 20 measurements per second we're doing 20 uh measurements per second for five seconds. Unless you're in the resnet acca 310 standard.
Then you're doing 10, second averaging because that's their rules for the standard 310, so you'll do 10 seconds in their category. Then we move up to the supply, pick the short guy to do this one okay, so we got those two measurements we can take a retake. If we feel like we fumbled something: okay, we could pick one retake and start over, but we're good so continue. Does it matter which way those are pointed? Yes, so take a tiny pause on this. You have a static pressure, probe, okay and what that's reading is static pressure so like. If you blew up a balloon, there's pressure in the blend right, you don't have any much flow or no flow. It's just ambient pressure. That's what this tube is doing.
When we point the tip in the direction of airflow, holes are out to the side and we're getting ambient static pressure. I don't know if amy is the right word, but i just made it up and it sounds good. So if we wanted, what we don't want is velocity pressure, okay in in this reading. What we don't want to do is turn it to where the airflow can hit the holes, because now we're going to get static pressure and velocity pressure combined.
So it's it's going to make us look like. We have more static pressure than we want, so every time we're doing static pressure readings we always want it in the direction of flow. That way. The area flows not hitting the holes, we're going to swap out the filter for the digital, true flow grid and then take a measurement.
So at this point we want to rip that filter out. So now you got them swapped out, you can take measurement and there's your flow right and you can see it and it'll. Let you look at it before you go to continue and get to that diagnostic screen in case you feel like something's, maybe just not right. Like maybe just ahead and have it in there all the way or something like that, you did fine.
So let's click continue. So there's our diagnostics right. Our airflow we're moving 344 cfns for a ton so, like ideally, perfection right, we're moving the right amount of cfm's per ton for this climate, total external static pressure. 0.56.
You know this is a dynamite install right here like this is this is right. There close where we want to be shout out to the install crew, that's right, but we can also see where our pressure drops are now. If we wanted to internally look at ourselves and say man, what could we have done better on that job? If we wanted to take it to the next level, this is where we could look at supply plan and pressure and say well we're at 0.34. We could have brought it down a little bit that would have brought external static pressure down a little bit which we have room to stay in the green there yeah there's a lot of play.
We could take it down a little bit if we wanted to. It. Doesn't mean we're busted we're good, it's like. If, maybe if we want to get a little bit more efficient, we could right think of it as like, an efficiency scale.
At this point, we can get into that in the detail screen: okay right about what we could do so flow's, okay, high hit pressure. Yep we go back. Of course, we can hit the pdf button we can enter our customer's information like we did before, generate the report and take pictures if we want now, let's say you're in and out you're ready to like move on to the next job, five o'clock, five o'clock ready To roll you forgot to send this to the main office or the homeowner calls, and it's like hey. I want to copy that report. Maybe you sent it to the office, but we forgot to send it to the homeowner. You can go back into saved right and you have your copy test. Three right there go to test three. You can then go back to your diagnostic screen, generate the report and send it out later.
I want to you, don't necessarily have to do it. So if you forget about paperwork like some people, i'm not going to say any names myself, there's a way to always catch up on it. Yeah. That's a nice feature that i like thanks for watching our video.
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