And in the final video in this series, we talk about vacuum. We talk about some basics of vacuum. We talk about some vacuum practices for larger jobs. So again, we're talking to Market Refrigeration Technicians here.

there are some special considerations, but the basics are still the same. We need to make sure the system is clean, dry, and tight. and vacuum is a huge part of that. Big thanks to Matthew Taylor for helping us create and present this excellent training class.

Thank you! So we complete our nitrogen test. What are we going to do? We're going to vent our nitrogen to atmosphere and we're going to begin our evacuation process. That's that's next. Okay, so why are we doing that? Well, A lot of guys use our our vacuum as our leak check, right? Well, that's what our pressurization really was about.

We can use vacuum for that, but the real purpose of our vacuum is to pull that moisture and air and non-condensables non-refrigerants out of our system. That's really the purpose is to clean the system now. So so how do we do that? We're going to pull down into the deepest Micron we can so that we're going to cause that water vapor to boil and then it's going to be gas and we're going to remove all the gas that we can now. Brian's been talking about the old guy a lot and I'm thinking in my head that's my dad, right? It's possible might be me a little bit.

sorry. So getting a little older and I'm noticing that the way we did this years ago and versus what we're doing today are very different now. One of the reasons for that is our our vacuum pumps are vastly superior. Our micro engages are vastly superior.

What we've learned about how all this works is vastly superior. And as we've said before, it really didn't matter quite as much as it does today. So today, with modern Poes modern electronic valves, all that stuff, this is far more critical than it's ever been. So if you got the old guy who's been telling you, you know, yeah, just give it a little burp a refrigerant there and you're all set.

That probably was true in 1980, right? Uh, 8. 1980 was a long time ago. So so we're not going to do that. We're going to learn the proper process to get these.

Get it, pull a good hard vacuum and we are going to do that over here as well so it won't go all the way through that. But but I will tell you. One of the things is, we want to start with a good vacuum pump. and I told you, modern vacuum pumps are better than mine, right? I've got one in my house that's probably 30 years old that just won't touch.

This won't even come close to this. If I get 500 microns out of that, it's you know. I Pat it on the back. It did a good day, right? 50 50 is the standard today, right? So if I hook up my micro engage to my vacuum pump with nothing else, I should be able to achieve about 50.

that's really, really low. That's extreme, right? So so know that. Second thing that we've learned is those quarter inch hoses. Uh, they'll do it eventually.

Uh, eventually. eight hours, you know, versus 30 minutes kind of thing. So so we've learned the diameter really matters. that's right.

So you know the new standard today I'd say is 3 8 a half inch if you can use it. but you the quarter inch is just is just not going to cut it so that you know that's that's just one of those best practices to to get used to. The next one is riding that vacuum pump around on your truck. All right.

See, you guys do this all the time. They leave the cap open, They leave the valve open. You're going to fill that vacuum pump with moisture while that's happening, right? Oops. So if you're going for that old 500 from 1980, you're going to make it.

but you're not going to get much below that. so just be careful of that. All right. And then the last thing is the ballast.

and I could probably talk 20 30 minutes about why we use a balanced and the advantage of that. but just know that that's a thing in it. and if you don't know a lot about it, definitely talk to some folks that do one of the big things we need to know is that we should be using our ballast to keep our moisture from condensing in our oil while we've got moisture right? So we'll close that off and and we'll use it to pull on down once we've boiled some water out and and it's a minor amount. Okay, and just for fun, we're going to inject a little bit of water into one of our pipes here and then pull a vacuum on it so we can actually blow that out.

It'll be kind of neat to watch and that brings up my oil. So the next bit here is vacuum Pump oil is probably the number one biggest thing that as a service on the service side I can do to control how well my vacuum pump works. When my vacuum pump oil is is crap. I'm just not going to pull a very good vacuum.

Not only am I destroying my pump slowly, but it's just not going to do a good job right? So good practice on a giant supermarket. You know we're doing a pulling a huge vacuum something like that. We're going to change oil in that during that vacuum several times. When we get towards the very end and we're trying to get that really really deep vacuum and we're going to start that segment with clean oil, you know we just pretty much have to.

Okay, so some other best practices. Uh, on you know things that we've learned over the years. My dad would not have told me this, right, but I'm probably not going to use my manifold set my gauge set while I'm doing this. could I Well if it was all tight and it was all in great shape.

Probably. But, but the new standard today really is the core removal tool. If we think about that for a minute, pulling through a Schrader core is really magnificently slow. it will achieve it once again eventually, right? But we've learned that pulling those cores out of there massively improves our speed.

Well, we're going to use that same tool now because modern tool removal tools are rated for vacuums. Deep vacuums probably better than my manifold set, honestly. So instead of hooking up my manifold to control my valves, I'm going to use my core removal tool I am going to pull the cores and I'm going to use that valve to control all right? So that's a huge change, right? We mentioned the 3 8 hoses. So I'm going to go with a larger hose to my vacuum pump.

I'm also going to set up my micron gauge as far away from my pump as possible. Now, as a technician, it kind of crushes your ego when you flip that switch. It's great to watch that pressure just drop right on down because it's right there at your vacuum pump. But the reality is the that massive system and the bigger the system is, the more dramatic this effect will be.

It's I got to move it to the far farthest Waypoint as I can from that vacuum pump to get a true reading on what's going on in that system now. I Was talking to Nathan a little earlier today and he was talking about sometimes two or three hours after I've turned off my vacuum pump my vac, my micron gauge will continue to fall if I'm far enough away and the system is large enough, that's how long it can take to equalize through that through that whole system. So so those are some some good practices. Once I've completed my vacuum, I've pulled down as far as I would need to go.

I'm gonna I'm gonna isolate that and I'm going to watch what's called Decay I'm going to watch how quickly my I lose my vacuum. Okay, and one of the misnomers that we have today as technicians is, you know I think that that vacuum should just be right where I turn it off should stay right there uh and hold. and if it doesn't I gotta leak. Well, the reality is today's equipment and techniques.

uh and and the tools we have. Uh, we can actually see the system is not scientifically perfect for holding a vacuum. It's going to leak a tiny amount and if you look at you know valve manufacturers, they all list the the amount of leakage that's acceptable, right? you know in the Practical world, there's none. For us, it's none.

We don't have to add another 100 pounds of gas once a year because our valves leak the correct amount. It's way less than that, right? We've never had to worry about that in the past because we couldn't see it right. You know, if our gauge said 29 inches and it sat there at 29 inches, that was good. You know today my micron gauge is going to show me no, that's 50 51, 52, 53 microns, right? I can actually see that.

So that means I've got to be able to distinguish between what's normal and what's leak. Okay, and that's one of the things we're going to talk about today. When we actually do this test is, take a look at her Decay and determine you know, is that okay or not All right, Anybody know? What? Does anybody know what a micron is but a micron a micron is a millionth of a meter of mercury column pressure. So when you talk to Old-Timers and they're like, why do I need a microengage it says 29.9 on my gauge I'm like, you know what? I Agree I want you to measure off five feet for me, You're like, all right, well give me a tape measure I'm like no, I want you to do it with your odometer and your truck.

That's what we're doing when we're trying to measure vacuum with a regular gauge. It's not that it doesn't measure pressure, it just measures in a scale that's not useful at all for what we need to be measuring in vacuum. But that's also why to what Matthew's saying, it may sound like crazy that we're saying every system leaks. Every system leaks.

Every copper joint leaks at the molecular level. That's all we're saying. And a micron gauge is just so accurate that you're going to actually start to see that. But if you're if you're doing a Decay test and you're staying again, you know you let it hold for 24 hours and you're staying under a thousand microns.

Or it depends on the application obviously. Um, that's where that standard it's It's a little bit of a moving Target depending on the system and the internal size, but just know that that it doesn't mean something's broken, it just means that you need to know what the what the standard is for what you're pulling. So we're going to go ahead and kick this off. I'm gonna do on this table.

I'm gonna pull a vacuum I'm gonna show you the system that we're using. Uh, this is the the vacuum micron gauge that all the techs have access to. These are the tools that the techs have access to as you can see labeled on my vacuum pump. It is actually one of the techs uh, tools that we're using.

I'm going to set that up and get that system running and then while we're doing that and letting it pull down, we'll go ahead and do a pressurization on a small piece of copper and demonstrate the the proper process for that. Then we'll come back to the vacuum and see what's going on. One of the challenges to pulling a vacuum we talk about it's getting rid of moisture that's you know that's really one of the big things. So just for fun I Said I was going to add some water I really am going to add some water to this and we're going to watch because I can graph the the way my vacuum pump runs I can see that water boil off on the graph and see when it overcomes that.

It'll be pretty neat. When we're done, we'll cut open that tube and see. is it dry, right? Yeah. I'm going to go ahead and cap that while we got some water sitting in that.

So let's let's talk about this. Uh, just for a minute. My setup here. So this could be any size system, right? This could be my entire store.

This could be a residential air conditioner making a loop. Whatever. So that this this vacuum pump could do a whole store. Yeah, really? Yeah, No, it's it's a it's a question of time, right? right? It is a question of time.

But this absolutely could pull down an entire store. Uh, would I want to do that with a live store that's got groceries? Of course, Not right now. I've got a Time issue, right? But if I if I don't have, if I've got all the time in the world, why not, right? Uh, this type of a a system is for a service tech. This is a really convenient size.

Uh, for a technician to bring in, he's got an isolated compressor. He's got to make a repair. It'll pull that down very quickly, right? rather than a store? Okay, but I may do circuit right or two, uh, easily with something like this. Now in my presentation I was talking about the size of our hose.

We've kind of figured out those quarter inch hoses. Once again, they'll do it right. It's just a function of time. Well, it's a big change, right? A quarter inch tube doing the same amount of work Roughly 30 minutes versus eight hours for three eighths, right? That's the difference.

30 minutes and eight hours ballpark. So uh, so we've We've figured out that Yeah, that's not a great way to go with a quarter inch. Now that's assuming I've pulled my cores Also right? That was. The other thing we discussed is I got to take my cores out all right.

So I'm going to attach to to one of my fittings or two or three, right? So if I'm if I'm hooking up on a rack for instance, I'll have a bunch of different places I can connect I got four. Why not use them right? Use as many as you need it. The pulp itself could be rated somewhere. most modern pump somewhere around six.

Uh, maybe up to eight. Uh, a quarter inch hose with a Schrader can pull around point seven, right? So I'm not using anywhere near the capacity of the of the vacuum pump itself. If I don't do something like I'm talking about, go to 3 8 hoses, pull the cores if I want to try to get, you know if I've got a seven on this one's an eight CFM pump. if I'm gonna try to pull all eight of that, I'm not gonna get that out of this either, right? So I'm going to go ahead and connect more hoses to try to pull all eight right? Why wouldn't I do that when we're talking about pulling down an entire store? Yeah, I'm definitely going to do that.

In fact, I may I may need even more. so I'm I may actually hard pipe my vacuum pump to the rack instead of running hoses right. Might do that depending on how big a system it is and and how quickly I want to pull down. Okay, so so we've been talking about pulling our cores.

What are we talking about? Well, there's you guys know we got caps that we can pull a core out of, but I'm talking about using a tool to do that and the reason is not necessarily because it's under pressure when I'm starting. maybe when I'm done right. but this is that valve I was talking about in the presentation I want to be able to isolate my vacuum with a vacuum rated valve. Okay, these new cores and I say new probably the last 15 years are rated for vacuums.

Okay, so this is probably a superior valve than my manifold set unless my manifold set's pretty new. Also in really good shape. Okay, so when I'm going to take this guy, I'm going to pull my core out which I've already done on this on this particular one. I'm going to set my my tool now I do have a Schrader on the side of this guy that I could use if I needed to.

You know for service right here. For instance, if I'm going to charge the system from a vacuum, I pull a hard vacuum and I want to add refrigerant. Well, I didn't use my manifolds, how am I going to do that? Well, I could connect right here. Okay, that that is an advantage of having that, but isolating my vacuum is what we're talking about.

So that's why I'm going to use that valve. Now you guys know I just put water inside this thing. So I am going to be a little cognizant of keeping that out of my pump in my micron gauge as we go. That's why I turned that valve off before I connected it.

Okay, so the other thing that I told you we want to do is connect our micron gauge on as far away uh from our vacuum pump as we can. Okay, so I'm going to put it out here on the end because I don't have much piping right but this is representing a Far Point on my on my rack right, a case inside the store maybe my farthest run right and I'm going to turn on my vacuum pump now. Modern Micron gauges do have some type of Bluetooth technology. This is not required for pulling a good vacuum, but it is a very powerful tool that we can use for a lot of things.

One of the questions that came up in the Q A is how do we report what our vacuum look like. Well, this is the device that'll do that. It's going to send that to my phone because my phone's connected to it. So when I when I turn on my Bluetooth fire it up here and I've got it right? So so I've got a picture of my Micron and right now it's not great.

Okay, okay I'm an atmosphere right? So so it's showing me that well I can record this whole pull down process and and have a running video of this thing. It will also record the graph right so I can see what's happening in my my actual microns that is that is pulling down this part is a tool that that is new and when I say new it's new to Modern Technicians my old man and Me growing Up did not have this tool. This tool is a visual representation nation of what's going on with my vacuum. So I can see when I hit water it will show up on the graph right I can see when the water is gone I'll see that on my graph right in the old days what am I see I'm seeing a gauge at you know a meter 27.8 27.9 20 I don't know what that means right? This is going to be really obvious.

Okay then the second thing that's going to happen is when I get done and I shut this thing off and I start watching my Decay That's when the question started in the technician's mind. he sees that number Rising right? Is that too fast? Do I have a leak or is that normal? How do I know, right? My graph is going to give me a nice physical representation of what normal looks like and what a leak looks like I don't have to guess anymore, right? So that's a really powerful piece. Okay, so we talked about our gas ballast a little bit. Uh, the the idea behind the gas ballast once again.

I'm not going to go super deep into this, but the concept here is I'm pulling water out of my system right? I'm boiling it by creating a vacuum and lowering its boiling temperature. Well, when it leaves the pump and it's exhausting, it's going back to Atmosphere it's going to condense. It's going to come right back. It's going to be water again, right? Well, I don't want that to happen inside my my oil for my pump That will contaminate my oil.

All right. So the concept between the gas ballast is: I'm going to open a system that allows a little bit of air to be injected right in that exhaust that prevents that water from condensing. Now what What's the cost? Why don't I run like that all the time? Well one, I'm going to get a lot of smoke coming out of this guy right when I do that. I'm going to have some oil going leaving the the device in a Mist right? So I don't want to do that too much or I could fill up my my room with oil depending on where I'm doing this.

or I could run out of oil for my for my pump so I don't want to do that and then the second is it's not quite as efficient. Still really efficient but I'm probably not going to get that 50 Micron at really low level vacuum if I'm if I've got my ballast open. So what I'm going to do is I'm going to leave it open long enough to to clear all that water and get that out of there. And then when I start that final pull down I'll close that ballast off.

Get the whole efficiency of my vacuum pump as I as I pull the rest of the way down. That's the concept behind that. Go ahead and fire my vacuum pump up. This particular one is going to give me a visual indicator my ballast is open.

That's what it's doing. Most most vacuum pumps don't do that. It is kind of cool. But as as that's going right now, I'm pulling a vacuum to here I'm not going any farther than that, right? So my system is not open to my my vacuum pump yet.

My micron gauge is still showing the atmospheric pressure as I'd expect. All right, this is how we would do this now. Once our pipe, our piping, however many systems we have are purged, we've got all the air out of them. We're going to start opening up the system and adding that to load as it were to our vacuum pump.

In this case, it's just one valve and that is going to start pulling down. I'm going to leave that sit for a second. More than a second, right? So let's see what's going on over here. This guy says I'm all the way down to 165 microns.

Holy crap right now let's keep in mind it's a pretty small piece of pipe. but also keep in mind that I shot it with 30 cc's of water. All right, that's pretty impressive all right. So this graph is really dramatic.

Most of my grocery stores this is going to be much more stretched out, right? This is just because it's so small. Okay, but what I can see is I can see this line pulled right down and then it stumbled right. You see where the gray it was just yanking the stew out of this and all said, oh and it started Rising right and then it recovered again and pulled the rest of the way down right? That's that little tick that I see there instead of a nice smooth line. Okay, so I hit my water.

hey hey I hit I hit liquid water at that point and I couldn't pull a vacuum right? What happened was the reason went back up is because I started boiling the water into vapor I was adding gas to the system. My pressure went up right until I evacuated it so my water's gone I can see that right? water's gone now. I'm going to do my final vacuum. Okay, I've closed my my gas ballast and I'm really digging in now.

Okay, now the gains that I'm gonna make at this point are really slow. All right. I made huge gains. Getting down to 168 microns right to get from 168 to 50 may take a couple hours, even on this small piece of pipe.

Okay, so so here's where my gains get really, really slow. and this is where we've got to decide what's good enough. Okay, the spec of our customer often is going to tell us 500 microns, 200 microns, Something along those lines. That's what we're going to try to achieve.

I'm at 167. Now, if my spec was 200 microns, would this be good enough? Technically it would. Realistically, as a service technician, I'm going to try to get all of the water out of this I possibly can, right? What I'm actually probably going to do I'm probably actually going to close that off, let it sit for a few minutes, right? A whole rack few hours, right? I'm going to let it stabilize, let everything, any little pockets of water in there, boil off, all that, let all that happen, and then I'm going to open it back up and I'm going to pull it down again. Okay, is that required? No right.

But is that a best practice? It is. And it's a leftover from the old days of triple. Evac right? That's what we all learned in school. We're gonna pull it down three times.

Well, we're going to kind of do the same thing. The difference is, we're not going to break it. We're not going to break our our vacuum with refrigerant, right? We're just gonna let it stabilize and then pull it down a little bit more. This is a hundred percent flexible on my situation, right? If I'm a service tech I am not Triple E back in anything, right? The other reason the other other challenge is it's probably tied to a ball valve on a live rack and I'm pulling some refrigerant through the ball valve, right? So I'm not even going to see 200.

That's why no customer specs 200 microns on a live system, right? Because you're going to pull right through the ball valve. Okay, so uh, so that's not going to happen right? But if I'm building a new store, why wouldn't I do that right? One thing I'm going to point out here: I told you I'd show you a graph of what a leak looks like, right? I got one right now. Okay now though, I don't really have a leak. really? What I have is I didn't pull down far enough so I've still got some moisture in there.

But you see when I hit that bottom and then my line came up with a really hard line, right? It's a straight up line. Looks almost like a rectangle. Okay, that is my indication that I'm not okay. All right.

if I see that when I turn off my vacuum pump All right I've got a leak or I or I didn't run long enough, right? That's the. That's what it looks like if I get a nice instead of that straight up line. If I get this kind of a gradual line that goes off to the side nice and slow. That's what normal Decay looks like.

I Can tell this thing that I'm done and and we'll see what what it thinks about my Decay All right? So in the interest of time we failed our vac, we failed our DK test. But we want to see. Did we dry it out right? So we got down to 168 microns for what? Five minutes? Maybe 10? Not very long, right? But we saw we got through that hump. Okay, so we expect the majority of our moisture.

Anything we can detect. as human beings, it's always gone. There's probably are some molecules floating around in there of water, right? That's why I'm I'm failing my DK test. Are we going to be able to detect that? Probably not.

right? I don't know. Let's see, Be kind of fun. All right. So I'm going to shut off my vacuum pump I'm already closed here.

I'm going to break my vacuum now. The way I would do this in the real world is with refrigerant, right? If I've passed all of my tests, everything's good. I've got my vacuum. What am I going to do now? I'm going to introduce refrigerant and I'm going to put a positive charge on the system so I can't pull any air or moisture back into it.

It's now positive and I'm ready to start charging for my startup process. That's what I would normally do. Okay, today, we're just going to blow the the vacuum right off of it. just opening some things up all right.

My Shredder is not in the end so I have no pressure. Okay, but I want to see what's going on in here? Pass that around. We got any water inside. you guys saw how much water I put in that right? Pass it around.