Good morning, everybody um today begins a new chapter in i know. I know it's dramatic, isn't it uh a new chapter in our classroom training wherein we actually create something new? So, like a chapter like a chapter and a book say um yeah, so hands-on training is the undisputed champion of how to learn things in our trade um. Unlike mike tyson, am i right come on. You know seriously.

I mean you clearly won, but you got to finish the thing you know what i'm saying: don't pull all right. That's enough, all right, okay, so, okay, so we need more hands-on training. We need more hands-on training, even when we're in here, but the trade in general needs more hands-on training. The problem with a lot of hands-on training is that some people get hands-on and then other people watch - and that's not that helpful.

So we want everyone to get more hands-on training, and i also want you to think i just want you to think period. No, i want you to think uh more deeply about the things that you're doing. I want you to be challenged uh when you are learning rather than being fed things by me, so we are going to develop a platform for the industry um. The one that's in the back of the classroom is the first model built by bert and ryan and corey, but we are going to improve upon that design iteratively, which means slowly step by step, improve upon the design until we aaron how's things, yeah good to see You buddy until we have come up with a good platform that can be easily replicated by us and also by others um so objectives objectives.

Are that our goal objectives? Are that our goal that is redundant wow? Our objective is to use a window unit, a very inexpensive window unit, the most inexpensive window units that we can find they can be easily purchased at your local home depot lowe's or on this new little site called amazon.com, which is where we purchase these three. We can use these components and reconfigure them in multiple ways in order to demonstrate the basic refrigerant circuit, in order to demonstrate electrical in order to then continue to reconfigure them in order to do things like refrigeration, starting with high temp, medium temp and then going into Low temp and be able to do things like refrigerant cycle testing, evacuation recovery again, like i said electrical diagnostics, but then even just wiring. It up yourself. Changing fan speeds in order to change condenser, airflow, evaporator, airflow.

Add restrictions into the circuit change metering devices, all those sorts of things that we do on a regular system. We can do on a smaller unit like this, and the question may be. Why would we bother to do that when we have perfectly good full-size units? The reason is, is that with perfectly good full-size units, a they're, expensive, b, they're, 240 volts and uh and c, i can't think of a c right now, because i don't have it written out one person at a time you don't want to break it. Was that one person at a time one person at a time? That's what it was.

That's what i was going, it's one person at a time, so there are labs out there, uh and god bless them. Where they've got. You know 20 sets of identical equipment so that everybody can work on their own unit throughout the school year. That's great most people don't have that including me.

So, even though i have a really nice lab up at lake tech and it's got really nice training equipment. Those early stages, where you don't feel great about throwing somebody on a you, know fifty thousand dollar piece of training equipment and just saying hey there have at it um you can easily do it with a small window unit, and so this is the challenge that i Want uh us to rise to here at kelos is yes we're going to tear them apart, because we're going to learn and put them back together, but we're also going to tear them apart and put them back together. So that way, the industry can come up with a better way of doing this, so that anybody can easily produce, if they're so inclined their own training equipment, so that every student can have their own unit. That's the goal rather than having or a team of students and in this case we're going to start with teams until we can kind of establish our our system.

So any questions about that before i go on. No, we don't even have an official name for this. Yet um we could call it the uh universal training platform, something like that. Um and i'll go into a little bit later, some specific things uh that we would definitely want to do with it um.

We learned some things in building this first, one uh that i think are gon na uh kind of instruct how we build the the next ones uh. But there are some some other things that i want us to do, rather than what we did over there. But the goal is to make this work very much like a residential standard system rather than a window unit. So we don't want to have you know the kind of some of the goofy ways that window units are built.

We want it to be built more like a regular unit so that it's serviceable and that sort of thing now before you all fall asleep. What do you think? One of the big challenges is with working on a window unit rather than a typical unitary split system? Accessibility, space space right, so it's hard to it's hard to get in there. It's things are smaller, so that's one of the things we want to do is spread the components out. So that way, we can actually access the lines in between and we can actually work on it more easily, which is uh what we did with the first one.

What are what are some other challenges that you face with working with a window unit? Other service? Are there service ports on it? That's another good question: no, there are not service ports on it, so that is. That is something we have to overcome and we'll talk about that quickly. But what else type of refrigerant controls the controls are different? That's a good one type of refrigerant, that's a good one, so type of refrigerant and quantity of refrigerant are probably the two biggest challenges, and so these come with a factory charge in them. Anybody care to tell me what the factory charge is on the on the data plate there.

Obviously they come with a factory charge in them that was sort of a ridiculous statement. It's right here on the side. What does it say? 6.17, ounces, 6.17 r, 32. 6.17.

Ounces now there are rules in the u.s about how much of this type of refrigerant can be in the equipment. I'm not even going to quote it right now, because it looks like it's going to change very very soon, and it's not the sort of thing you're going to memorize anyway, but the point is, is that this type of refrigerant is a flammable refrigerant. More specifically, it is what is called a mildly flammable refrigerant. It is an a2l.

So if you think of you know the letter number designations, a refrigerants are non-toxic. We pretty much only work with non-toxic refrigerants, pretty much um residential light commercial you're only going to run into a refrigerants, and it used to be that we would only be working on a1 refrigerants, which means non-toxic non-flammable. Whereas now we're seeing a lot more a2l's and then even a3s, so an a3 would be like propane or isobutane. Those are called hydrocarbons.

So this r32 is an a2l refrigerant, uh refrigerants, like r290, which would be the most common a3 hc which stands for hydrocarbon, and so this is what we got, and this is a this is a hurdle that we're gon na have to face when dealing with small Window units nowadays the smallest least expensive window units nowadays - and this is very recent - that this started happening come charged with r32. That's the bulk of them that you're going to buy nowadays the one that we have in the back, that one came charged with r410a. Now it would be great if we can find them with our r410a, but what we got is our 32, so we need to talk about some best practices when servicing, something that has a flammable refrigerant. Now, if it was propane, we would have some uh disadvantages and some advantages.

What's the disadvantage to propane compared to most other refrigerants, i already said it, but it's flammable right, it's very flammable. It makes fire real easy now. Good thing about our r290 is that it's a very good refrigerant, good thing for r32 is it's a very good refrigerant. Pretty low pressure r32 is more like r410a, but our propane is more like r22, so they're easy pressures to work with nothing.

Crazy, carry oil pretty well um, so they work nice. As far as refrigerants, the downside is flammability right now, good thing about r290. Is you? Don't have to recover it, you can vent it, which is kind of cool right. You don't have to have recovery equipment because a lot of people ask that.

Well, is your recovery machine rated for hydrocarbons? Is it rated for r290? You don't have to recover it. So the downside, of course, is is that you wouldn't want to dump r290 inside of a restaurant or something like that which right now, that's where you would find most of that equipment. So it's flammable and you don't want to just vent it inside of a restaurant. So, let's just think quickly see if we can use our common sense.

Let's say that you're working on an r290 appliance, you need to get the refrigerant out of it safely. You're in a restaurant, you don't want to use your your recovery machine. How would you get it out without risking anyone safety? How big is the piece of record good? Well, i mean you're limited by charge anyway, so everything's going to be under a pound, i mean like: is it a double door, or can we wheel it outside yeah? Well, so that's one thing: if you can wheel it outside and vent it there great. That would be your first thing.

What, if you can't, you could use a long hose right that you that could that could do it now, some of it's going to be left in the hose so think about that shortly. What no that's a bad idea! I don't like that idea at all. That's a terrible idea. I'm sorry that you just repeated that in front of everybody.

Another thing you could do is you can take a large recovery tank, that's empty! You can pull it down into a deep vacuum and because of the large internal volume of that tank, you'll often get all of that refrigerant out before that tank even hits atmospheric pressure again depends on how much refrigerant and size of the tank, but that's a good Technique you can use and in fact that's the technique that we're going to use on these i'm going to pull a big tank down into a deep vacuum and again i haven't done it before and i haven't done the math on it, because math is so boring. There's no such thing as a deep vacuum in our world. Burke says: there's no such thing as any vacuum in our world, we're pulling it down below atmospheric pressure below 14.7 and i'm quite certain. It's called a good vacuum that that pressure differential will draw.

All of that r2 r32 into the tank um now good news is our recovery. Machines will work with this r32 as well and a2l. Now i haven't seen that they're rated for r290. I would doubt that they are but again, why would you recover our tune id with a recovery machine? Currently, there's not enough of it for that to be a sensible thing to do currently, but with these we do have to think about not having an open flame near uh any any, even residual.

We don't want to have an open flame near these refrigerants. Okay, so like when you're after you've recovered it you're going to want to purge it before you try to braise anything correct indeed, indeed, so in terms of how you would do that, you would use a pinch off tool like this. Generally speaking and again, i don't know if this has processed stubs on it or not. Oh yeah, yep we've got a little a little processed stub thingy here.

This is just like an end seal off, and so you can put your pinch off tool where the pinch already is. You can cut the tube and then you can put a stub on it now. You know how i just said: you don't put an open flame anywhere near it. You actually do when you're, putting when you're brazing in your schrader port, so you would crimp this on then you'd cut it and you'd make sure that it's not leaking at all.

You use bubbles whatever to make sure that there's no leaks coming through and then you would braise your port on and that's where you definitely don't want to. You know, burn through it. Then you take your your crimper off and you just kind of crimp it back. The other way just to just a touch because again you're, not you, don't need a ton of flow through it just enough to get the charge out and get a new charge in later.

That makes sense. Did everybody see this here? We can do b-roll on this later if we need to, but so you take this just crimp it down make sense. Once you cut this you'll see if any is leaking out or not, and that's a pretty standard way of doing that now you can use, they make piercing tools as well. In this case, the tubing is so small that a lot of times the piercing tools are actually going to collapse.

Now you can use a saddle valve, take the saddle valve off and those will work. Okay, i think we had some sitting around here recently, but but generally speaking, this is your best bet, because now you've got a permanent port attached here now, in this case, since we're going to be completely disassembling, it a piercing tool, one of the ones that are Really designed for smaller lines would probably be your best bet again. We noted when we were doing a ton of recovery on some sealed condensing units that you have to think about where you use those piercing tools, because they tend to actually collapse the line. I'm talking about the ones that use the um, the vice grip style, whereas the saddle valves um that are specifically designed for it uh they work pretty well, they do tend to leak, though so they do tend to leak um in terms of what you do before You actually put a torch on it.

If there's any residual, you would definitely flow a lot of nitrogen through it. So you first get the refrigerant out. R32 is a regulated refrigerant, so you do have to recover it, but that's where my suggested method would be negatively pressurize a tank. You pull a vacuum on.

You got to pull the vacuum on the tank anyway, before you use it and then just hook it up and do it that way and you can actually pull the vacuum all the way on the hose, so take a take a hose with a ball valve on It pull the vacuum all the way down, shut the ball valve then hook the ball valve up open it up and pull that refrigerant out. That would be my suggested method now, in terms of once. You've already got that tank under positive pressure. Now, you're not going to be able to do that anymore.

If you want to put more in the tank, then you're going to have to use a recovery machine now with the with the charge. That's this small, a recovery machine is going to be. You know most of that refrigerant is going to end up in the recovery machine. Now again the field piece machines that we use um.

I haven't looked on the navac machine, but i'm sure that it as well are specifically rated for a2ls. Everybody follow what i'm saying here: a2l that's what this has in it. R32 6.17 ounces is what it's got in it and that is that mildly, flammable refrigerant. So it's not it.

You know like we're playing it up, because you want to be really safe. It's not going to like cause a bomb or anything. It's not like you're going to be working on it and the things just going to explode in your face. If you were working with r290, you would need to be certainly more careful about that.

Now. A lot of people will say that you need a new vacuum pump to work with a2l's or r290, and that's just not true again. If you had left a lot of residual refrigerant in the equipment, then maybe but that's where flowing a lot of nitrogen while you're working, purging, nitrogen through uh and then and then pulling your vacuum. Because you have that that lower flammability limit, where you have to have enough of the fuel in order for it to really be flammable as long as you follow good practices, you're going to be fine in terms of suggested practices, they're going to also tell you that You should not leave any ports on an r290, a flammable or mildly flammable system, because ports can leak, and so you want to leave the system completely sealed again.

Most of the guidelines are going to tell you that now, in our case, we're not going to put our 32 back in these systems, because that would just make our life difficult. We're going to put 410a back in the system, which means that it won't work as well as it was designed to work, but we don't really care because in this particular case, this is for training. This isn't to make an efficient unit now. Does anybody know why they went to r32 versus r410a any thoughts on that anybody know where my coffee went.

I'm not sure it's over there you're doing that thing. You're behind this one. It is right here there it is more effective. That's everybody's favorite joke! It has a lower gwp than r410a.

That's the reason why, generally speaking, people are going to r32 but they've been using r32 in developing countries for a while global warming potential, but you knew that you're just you're just joshing, that's a real thing: yeah! Okay, all right! Okay, all right, okay, um, this one of those no-win conversations that i just don't have anymore all right, let's find about this yeah, let's so global warming potential is a big reason, but also r32 is a better refrigerant. It's just better in terms of its latent heat of vaporization, how much of it you have to move in order to do the job of cooling uh, it's a better refrigerant. In fact, it's one of the best refrigerants it's downside is that it is mildly, flammable and this whole mildly, flammable thing. That's a new term.

They used to just call it um. I forget what the a2s were called it. So it was like mid flammability or something like that: it's not it wasn't midfield ability anyway, we can find it but um they made the category a2l specifically, so that people would be less worried about using some of these refrigerants. That really aren't that flammable they're not flammable like propane, but they are still flammable so r32 is a great refrigerant.

There's nothing, there's no reason for us to be afraid of it. So long as we follow proper practices, um it is coming and it will probably be in unitary equipment. It's probably one of the refrigerants we're going to keep on our truck very soon. Daikin is already talking about using r32 in the u.s, as their replacement refrigerant for rf10a carrier has decided on a different refrigerant, and i always forget what it is are four one two three four yf is our is being used in cars and some small equipment.

It's not the one. That's going to be used in split systems, though that's not expensive yeah it is, it is pricey uh, so r32 in terms of its um similarity to r410a is nice in terms of its latent heat of vaporization. It's nice, it's downside is, it's. Is it's mildly, mild, flammability um, because r410a is actually 50.

R32. 50 are 125.. So what we don't like about uh r410a, what makes it not a great refrigerant is the fact that they add this r125 into the r32 and mix it together in order to make it uh an a1 in order to make it not flammable. But r125 is not a good refrigerant, it's a very good flame retardant, so they put that in there in order to keep the r32 from from being flammable.

So in terms of this first project, we have to think about the flammability again. Nitrogen is your friend make sure that it's all out before we proceed uh we want to put the ports on it and today the main thing that we're going to do before you all leave is jessie's already looking nervous, so it must be a busy day. Okay, the first thing you're going to do before you leave is we're going to develop or we're going to develop our three teams and we're going to come up with a game plan because, as we go in these classes, we're going to keep coming back. To these same units and we're going to pick up where we left off and we're going to keep building on it until we got three different, they won't be identical.

I don't want them to be identical, three different versions that then we can hopefully take what we've learned and build it into one really good prototype that, hopefully we'll have available and ready to uh present by the time the symposium comes up in march, so by then, Hopefully, we'll be able to have instructions written and have the images and kind of show, step by step, how we did what we did make sense, that's the goal and we're just going to keep doing it here, every every time we have a meeting or class. We will have meetings about other things that we can add onto it whatever, but we're going to come back and we're going to work for a little bit on these units. Then we can go away, gather up more materials whatever we need and then come back. The next week and work on it a little bit more any questions about that all right, thanks for watching our video, if you enjoyed it and got something out of it, if you wouldn't mind hitting the thumbs up button to like the video subscribe to the channel And click the notifications bell to be notified when new videos come out, hvac school is far more than a youtube channel.

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