What's the evacuation vacua tional yeah, actually good to use in the evacuation, video, okay right, so evacuation! I like it when Robby asked questions because he comes from that perspective of like not about our commissioners. True, so evacuation is pulling the inside of the air conditioning refrigeration circuit into a vacuum. When you pull something down into a vacuum. What do you think happens? You know? No guess no get! No guesses.

Okay. So what do you think happens to water? If you pull it down into the vacuum, it boils it boils at a lower temperature than normal right. Did you think if you think of it, just simply you're you're by removing your but you're, basically overcoming atmospheric pressure, so atmospheric pressure is 14.7 PSI a right, and so, when you pull something into a vacuum, you're not really going you're, not really going into a vacuum. All that you're doing is just removing the atmosphere, that's a way of saying it like so the atmosphere, that's actually waging Berggren, always says if you're actually removing mr atmospheres.

14.7 PSI a you're dropping down below 14.7 PSI a. We can't achieve a perfect vacuum between major vacuum in microns, because it's a very, very fine, fine measurement of pressure. You can't pull say anything down to zero, but we try to get the system down to if we can 250 300 microns in general. We definitely wan na get below 500 and we want to see it sit and stay below 500 for a period of time, or you know different vectors will say different things, but in general I like to pull it below 500 and then let it stand in a Standing pressure test for five to 10 minutes and make sure that it doesn't rise above 500, which is an indication that you don't have moisture, because if there was moisture the vapor pressure would overcome you know it would boil, and then it would increase that pressure and It also shows you that you don't have leaks so you're getting air out of the system that contains moisture another craft.

You know you're also getting my water, vapor or water. That's in system how liquid water can't be sucked out. It has to be boiled out. One 54.3 on the section is what I'm primarily going to watch we'll be a little bit of Equalization fluctuation with temperature, but should be, should stay right in that zone, so we're gon na, let that hold for a while standing pressure test bubble test.

The actual credit connection since you'll get so this is a CRT there's a couple decent brands, but I tend to use this particular happy on brand, so on a quart remover tool, you, you can only pull this out and push it in with this valve in the Open position this valve is closed. It's shut off so that it can't come all the way through, but neither can the refrigerant come all the way through. So, if you're removing a core place, this in here, tighten it down with it shut off to the refrigerant, so it doesn't leak, then open it and push it in unscrew the core and then remove the core then shut it off then remove this, and now, when You open this now, it's completely unrestricted into the system, so this is where you connect your evacuation hose and, if you're, using a micron gauge on the core remover tool, which is what we recommend you connect it to the side, pour with the Schrader, so micron gauge Here, vacuum gauge here: vacuum hose going to the vacuum pump here with the core removed and that's what we're gon na do now, so we've been holding now at 154 for 20-25 minutes or so we're ready to go ahead and pull our vacuum. So I got to attach the cord remover tools on both sides.

Attach our great big poses vacuum rated hoses background gauge, but I'm gon na do that quick pause here. So we do not pull the vacuum through the gauges, even though these are great set of gauges. All manifolds have some restriction in them and we don't want to add that restriction to our vacuum. So our vacuum is we're not going to remove the gauges.

We're gon na keep them here, because we need them for when we're ready to set the charge. But the evacuation, the vacuum - is going to be pulled directly hoses to the system through for removal tools, so removing the core. Now I keep the I keep the ends of the hoses sealed right until the final second. So that way the hoses don't become permeated with moisture.

Other part was just to pretend, so you can already see we've already their property. This week is coming out so fast. It's been like a few seconds. He is showing the saturation temperature of water and depth at this point.

The water would boil at minus 13 degrees right now, at this pressure. I have it set at a 300 micron target and then once we get to 300 microns we're going to valve it off at the core tools and do it decay let's go through now. While doing this and just show the configuration, we've got two big hoses a key. This is a 3/8 connector down to a half inch connector on the pump to 3/8 connectors down order inch at the core tool, a quarter inch connector at the core tool.

Either half inch hoses quarto on the other side, with the micro engage connected directly at the core tool itself, all right, so once we get to 300, then we do the decay test. A snap here to K right, there's a rate at which it's rising, which is very low, definitely within the acceptable range. So you can see that we just passed our DK Tess. Okay, Tess is fast it would you like to do just saying that we're well within acceptable range, I'm just going to continue it a little bit longer, but with only a minute in decay, it already pretty cool alright.

So I want to show you this. The blue back at by measure quick, which is what I used to sort of, demonstrate the evacuation and then the decay test. It's just a really convenient way of doing that, and it's a great application actually developed by my friend, Jim Bergman. So right now I don't have a blue vac connected, but I'm gon na show you the settings just real quickly in the different screens.

You solve this one and then you also saw the graph screen, and you see these there's a lines here. The red line and the Green Line, the red line, is the maximum decay target and 200 down there. The Green Line is the evacuation target, but what I had it set on when I did this particular test - was an evacuation target of 300 and a decay target of a thousand which, for a lot of manufacturers, that's similar to what they suggest so carrier has a Guideline like that, which i think is not to decay over a thousand after a five hundred micron vacuum in ten minutes, if I'm remembering correctly, but a lot of manufacturers have that sort of a thousand micron decay limit and then also I had the time below decay Target set to ten minutes, Jim Bergman suggest that you use ten minutes as the baseline and then you add a minute for every ton so based on Jim Bergman suggestion, this would have a 13 minute time below decay and then the question is, you know: where do We set the the Green evac and the 1000 decay. I set it there because that easily demonstrates how quickly it pulls down.

But if you look at Jim's recommended settings, if you go to Comfort cooling for new installations, he suggests you pull down to 200 with a decay of 500. If you go to comfort cooling for service, which is what we did, he recommends a evacuation of 500 and in decay of 1000. So actually we did better than the recommendations. It's just that the range was greater from three hundred to a thousand, which is why I passed the decay target test so quickly anyway, just just demonstrating how this works.

It's a really neat app. You can configure it for different applications, so, for example, if you're working on ultra low temperature ation, it has a very very low evacuation indicate argot if you're working on regular general refrigeration targets 500 and the evacuation target is 200 and it's doing the math on the Decay rate to tell you, as soon as you hit the point where the decay rate proves that it's not going to go higher than that decay target. Then it tells you that it's passed or doesn't you don't necessarily have to go the entire 13 minutes as well as soon as it calculates that you won't go over in the 13 minutes. It gives you that passing grade, which is why you saw that happen so quickly in the video all in all.

It's a great app for this, and you saw how quickly you can pull a great vacuum and do an effective decay test. If you have the proper equipment, I mean we did a vacuum faster than most people would do a typical vacuum. The old old-timers rule of 30 minutes and we proved that the system was in great condition and that it was not leaking and it was able to pull a very, very deep vacuum. So we know he boiled out that moisture.

So, thanks for watching we'll see you next time on HVAC school.