This episode of the HVAC school podcast is made possible by our excellent sponsors. First off the show sponsor nav AK, that's nav AC! You can find out more at navigable com. They make all kinds of cool tools, including some really nice vacuum pumps, just playing with the NRP 8 di. In my training room and it's a really nice pump, I think you'll really like it and actually that's what today's episode is about, but also I want to thank Aero, Asus and Aero Asus comm.

You can find out more about how you can use arrow Asus whole home air purification products by going to air oasis.com /go. That lets them know that you are a listener to the HVAC school podcast and to pay you special mind, because if you listen to this podcast, you are special, also the refrigeration technologies at refrige tech, comm makers of viper, the pan and drain spray. Dialog big blue. Many other products you can find them at true tech tools, comm and get a great discount by using the offer code get schooled.

You should know that I just used the Viper cleaner on my own condenser at my house. It was shockingly dirty. I also use the refrigeration technologies, Viper foam gun on it, and I really liked it. I followed the full process that John pastor Rallo laid out in his episode on coil cleaning, which you can listen back to in the archives, Matt's, refrigeration technologies and refrig tech.

Comm. Also uei test comm and the hub six four and two kits the six is the whole shebang. The four is the refrigeration pressure probes, as well as temperature probes and the hub. Two is just the air side, really great products.

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His initials are B, O or reason Brian or you've tuned in. I don't know if I'd call it tuning in when it's a podcast, you tuned into a podcast, I'm not sure, but you are tuned in whether you like it or not to the HVAC school podcast, the podcast, that helps you remember some things that you might have Forgotten along the way, as well as helps you remember some things you forgot to know in the first place, and today I'm on the line, if you will, with Kevin Maher and Kevin, is a really smart guy he's been an educator in the HVAC industry for a Long time and now he's working with nav ik and now that global comm makers of great vacuum pumps and many other tools and we're gon na talk through from start to finish soup to nuts on what you want to know about vacuum pumps. And some of you may say: well, we've been talking so much about vacuum. Lately, that is true.

We have talked a lot about vacuum: how to pull a good vacuum, but today we're focusing on the pump side what you should know about one of the most expensive tools on your truck the vacuum pump. So here we go all right today on the podcast. We have Kevin Maher and I learned right off the bat that the way he spells Kevin is VA and at the end, which is the Scottish pronunciation. So I learned that if you're gon na communicate with Kevin, you got to make sure that you spell it with the a and not with the I.

Otherwise he gets really offended. Oh, not really. I only make sure it's spelled right on my paycheck all right. That's the important all right anyway, I learned that was the Scottish pronunciation, which is my family interest ancestry as well, but anyway, Kevin's on today and we're gon na be talking about vacuum.

Kevin works for an a vac, which is a company that I've been doing a lot of work with lately and been trying out their tools and been very impressed. So before we get started Kevin, would you mind telling us a little bit about you and a little bit about a vac? I started in the HVAC business working on the wholesale side back in either 1981 or 82 worked for a number of wholesalers worked for several contractors moved to New England, where I again worked for contractors and also worked for wholesalers spending the last 15 years, working as A HVAC instructor training, hundreds of plumbing and heating people on how to install forced air heating and air conditioning systems. I've been very involved with our SES over the years, teaching their classes, taking the classes and actually being on the board of directors. For about eight years.

Oh cool yeah, I didn't realize that about our SES and I do want to put a plug in for our SES in Florida we don't have a real our SES chapter. It just hasn't reached us, but I love what our SES does and has done with training over the years they're one organization that really focuses on training and so just a quick plug out there for any of you who don't know much about our SES. I would strongly recommend that you look at joining a local chapter if there is one and get involved, because they do really great work. I have great online resources as well.

A lot of people have asked me about Nate education, for example. They have some neat classes. You can take even online, so that was a little aside there, but just while you mentioned it, I appreciate you serving with them, because I know that you certainly don't do it because of the pay. It's a passion thing yeah.

It was a great experience, but my job required that I do a lot of traveling and unfortunately, I had to leave, but it was a case of putting together Nate manuals. We were the first organization to put them together and we were able to build about 95 % of those manuals straight out of our existing training material. Our SDS really has a vast library of training materials, and I would certainly encourage any technicians to join our SES. Whether there's a chapter or not, because the emergence of online training allows the technician to learn the material without actually physically having to go to a class so kind of like this format, where they can learn on their own time and each technician can pick and choose What they would like to learn more about, so I think it's a great organization, and I believe it certainly still has a place and is still relevant in our industry, so tell us a little bit about nav a canned how you ended up working with nabek.

Well, I was just retired and minding my own business and I got a phone call asking if I'd like to provide technical support for a new HVAC name in tool manufacturing, and then I found out that nav expen around for about 20 years, actually a little more Than 20 years there, one of the largest vacuum pump suppliers in the world, making over half a million pumps a year and we manufactured vacuum pumps anywhere from two CFM up to 300 CFM. While our HVAC vacuum pumps typically are capable of pulling vacuums down to 15 microns, our industrial pumps are capable of pulling down to about two microns. We have over 600 employees in more than 80 countries, so we are truly a global company and we've now over the past year been introducing our own name into the North American market. Some of you may have seen the recent video that Jim Bergman did with a really nice-looking big white pump when he was doing a demonstration for his new hoses, and that was actually an a vac pump.

I kind of had to look closely out of like what is that thing and come to realize that NAV Act not only makes in the HVAC said, like you said, but they make these industrial vacuum pumps as well, which means that you're dealing with a company in A vac that has a deep breath of experience in vacuum, which is great to see because it obviously, whenever you see a new product that maybe you haven't seen the name before you want to know who are these people, and it turns out that navicomp have been Around for a really long time so today I wanted to talk a little bit about vacuum pumps in general and kind of some of the features and benefits of different types of pumps how they function. The oil sign there's a lot of questions about vacuum pump. So we have amount of trucks, obviously they're expensive tools, but let's start by talking a little bit about what is a vacuum pump for in the first place, and then how does it work internally? How does it actually do what it does the vacuum pumps main purpose is to remove non-condensibles from the system. It won't remove oil, but it will remove moisture, which is a real problem.

If we have moisture in our system, what happens is, as the liquid refrigerant goes from liquid state to vapor state, there's a tremendous temperature drop, and it is enough of a drop, especially in refrigeration systems, where the moisture will actually freeze where that temperature drop is an Additional moisture coming through the system will cause that restriction to become smaller and smaller and smaller as moisture freezes at that one point eventually blocking all refrigerant flow to the system. We need to remove that moisture by taking that moisture out with our hiim pump. We then will keep the small passages in our system free for refrigerant to flow through them, so primarily we're interested in removing moisture from our system moisture being the biggest thing. Not only does it cause freezing in your metering device, but it can also cause contamination of oil nowadays with pou oil and then you're also dealing like you mentioned, with non condensable gases like air, for example, air and nitrogen in the system.

Those also cause problems. So, there's a lot of reasons that we need to be pulling a vacuum. As a quick aside, you may have seen recently there's been a lot of explosions that have been happening, especially in some third-world countries, on systems that weren't properly evacuated, as we go to more flammable refrigerants, like our 32, when you leave that oxygen even inside the system, That can make for a much more explosive environment inside the system. So it's really important that we pull deep in effective vacuums and having a functional vacuum pump is really really important for that right and the one thing I wanted to follow up with the r410a and BOE oil is that moisture, combining with that oil becomes acidic and The last thing we want is an acid in our system because it can eat it.

The motor windings and eventually cause an electrical short in our compressor, which is truly catastrophic. So removing moisture is really really essential and in order to get that moisture out, we are going to remove the oxygen and nitrogen as well. Now, let's talk about the pump itself if you've been in the field for any amount of time. Obviously, you know what a vacuum pump looks like, but I think a lot of us don't really understand what's happening inside of that pump, what's actually going on inside there.

So can you give us just a quick primer on what goes on inside the vacuum pump itself? If you've ever taken a pump, a part of any kind, whether it's like on an out drive for a boat or a pump for a hydraulic system, something like that you'll find an impeller in there a vacuum pump is typically a rotary vane pump. So it looks like an impeller where it's got vanes on it in these vanes on the inlet side, create suction, pulling the air and moisture out of our system on the outlet side. As the vane and the compartment travels that compartment gets smaller and smaller. Raising the pressure and pushing the contaminant of the air the moisture out of that side of the pump most modern vacuum pumps now are two-stage pumps, which means they have two sets of these veins with two different chambers.

So you've got the primary chamber which is pulling the vacuum pulling the air and the moisture out as the chamber gets smaller and going towards the exit. The pressure goes up. It pushes it into the next stage, which again sucks that air and moisture out compresses it again and then that second stage actually discharges the contaminants into the atmosphere. So you have this two-stage effect, which makes it much more efficient in much faster at pulling a vacuum.

So your high quality pumps, your higher CFM pumps, that are capable of pulling a deeper vacuum than will generally be the two-stage pumps versus a single stage pump. Then right. Yes, most quality, modern vacuum pumps are two-stage. The one thing about a vacuum pump is that they are typically single speeds, so that kind of makes it imperative that you have a vacuum pump that is sized properly for your job.

I so a lot of text may have noticed the gas ballast that is on top of the pump, and I think, a lot of guys just keep that thing cranked all the way down. They never open it up and don't really know when they're supposed to so. What's the purpose of that, anyway, what that does is it allows the pump to bypass the contaminants from the second stage and just discharge it out into the atmosphere? What it really does is it helps keep your oil a little bit cleaner and longer-lasting, and, as we'll talk about later, the cleanliness of your vacuum pump, oil is very, very important. Typically, you should open that gas ballast valve a turn and a half or two turns allows the air and moisture from the gross part of the vacuum to be pumped out much quicker.

Typically, you would open the gas ballast and leave it open until you get down to zero somewhere in the neighborhood mm. Maybe 1,500 microns until you're really ready to start pulling your deep vacuum and some people will use the term roughing vacuum versus finishing vacuum. You leave the gas ballast open during your roughing vacuum, which is the first portion of the vacuum, and then you close it off when you get down to the lower levels, and actually I did some experiments recently with a navicomp and a couple other pumps just seeing How well they would do, and I was very impressed by the net effect pumps by the way. But one thing that I did realize is that even very small amounts of moisture within I was using ad assing chamber putting a little bit of moisture in and then testing it on pull down with different hoses, even with small amounts of moisture that will contaminate the Oil pretty quickly, so if you have a system that is known to be wet or you have a reason to believe that it's wet that's a good idea to leave that gas, ballast open and the roughing portion of the vacuum.

So that way, you don't contaminate your vacuum pump oil straight away right again, using that gas ballast can really speed up the time it takes to pull the moisture out of a wet system, particularly if it's been open to the atmosphere in an area with very high Humidity right or if you're, one of those technicians who gets the thing open and then one of these Florida thunderstorms comes in and you're, not able the system sealed up in time and that you might have gotten a couple drops in there, which I'm not gon na, Say that's ever happened to me, but okay, it's happened to me before so or if you're in Buffalo New York, where you've got a system where the piping has been open for three years. So there's all different scenarios where that gas ballast can really come into play. Great: let's talk about vacuum pump oil since we've already kind of alluded to it, a little bit first off what is vacuum pump oil? What is it made of it's a mineral oil, but it's very highly refined all the waxes taken out of it. It's ultra clear.

If your vacuum pump, oil is anything other than a very, very pale yellow, it probably needs to be changed if it gets milky or it gets brown, it's full of contaminants and it's long past its effective life. It has a very high boiling temperature, because the last thing we want is to start developing our own contaminants from our own oil that oil needs to be clean. It needs to be ultra pure because it's doing a number of things inside that pump and in order to be efficient, it needs to be clean and fresh yeah, and that gets to just a kind of a general recommendation. I have about vacuum pump oil for those of you who are ready to take your Navy exam pretty soon.

A word that shows up on. There sometimes is hygroscopic, and that means that it likes to attract moisture and so pou oil is hygroscopic and so is vacuum of oil. So if you leave vacuum pump oil open for any amount of time, it can become contaminated, which is why I would suggest using smaller containers, a vacuum pump oil. So that way, your the kind of single-use, which, coincidentally, is how the vacuum pump oil is shipped within that vac pumps is.

It comes with a couple very small containers of oil with it and then that just helps prevent contaminating it, because if you use this giant jug or a gallon jug or something - and you only use a portion of it in during that period of time, it can Become partially contaminated with moisture, even from the air, so whenever possible, try to use smaller containers and make sure it's nice and fresh and clear, like Kevin was saying absolutely and Pol is so hygroscopic it'll actually absorb moisture through the walls of a plastic container, which is Why it's always shipped in metal cans, the vacuum pump? Oil is hygroscopic and it actually acts almost like a paper towel on a spill of water. It is made to absorb the moisture out of the system, we're talking very small quantities of moisture. That would be difficult for the pump to remove so by absorbing it into the water or into the oil. We assure that that moisture is indeed out of the system.

Let's pin that down then. So. What is the job of the oil within that vacuum pump? What does it actually do within the pump? First of all, it lubricates the pump itself because you're talking about very highly pristine parts, with very, very close tolerances. Everybody knows that a micron is a very small particle.

It's one twenty-five thousand four hundredths of an inch and if you're talking about a pump, that's capable of pulling down to 15 microns or in the case of our industrial pumps, two microns, the tolerances have to be extremely extremely tight. So if you lose vacation, that pump is going to heat up from the friction and you're going to end up damaging your pump and, as you alluded to, the higher quality pumps are expensive and changing. The oil is relatively cheap compared to replacing a pump, especially for those people that work for larger companies where they may have to buy their own vacuum pump, but the company buys the oil, that's a pretty cheap insurance policy. Another thing that the vacuum pump oil does is: it helps the veins seal if we don't have the required viscosity of our oil, because we've got contaminants in it, it's not going to seal the veins of the pump as well.

Therefore, the pump won't work as efficiently or as quickly and again time is money, so we want our pump to continued or to work at maximum capacity or maximum efficiency. I guess is what I should really be saying, because we need to get that moisture pulled out as quickly as we can and then, as we talked about a minute ago, the final function of that oil is to help absorb contaminants so that moisture, that's coming out Of the system will have somewhere to be absorbed, so it can't get back into the system as that pump rotates around. So we want to be able to pull the moisture out and act again. Is that wet or paper towel picking up a water spill? That's what our oil is trying to do is trying to help us remove the moisture from our system.

I'm sure we've all seen it and honestly. I don't fully understand it for full disclosure here, but we've all seen that when you have a vacuum pump where the oil becomes contaminated, that the pump stops functioning as well, so initially it'll pull down. And then you get to this point where it'll even stall out and then you change the vacuum, pump oil and then it'll start pulling down again appropriately. And so it is interesting that that moisture absorbing function that that oil has that hygroscopic effect that the oil has does make a difference with how deep of a vacuum that you pull, which again I don't fully wrap my head around that.

But I certainly know it to be true, absolutely and I've seen it proven over and over again over the years, I've had vacuum pump. Manufacturers reps come into shops with micron gauges and just simply by timing, how long it takes to pull down to a certain vacuum. Even with just a hose attached to the micron gauge, it's amazing the difference in time when a technician brings a pump in where he changes the oil every spring, whether it needs it or not, then changes it in the summer and it's like you can see the Light bulb go off, oh yeah. Maybe this is something I need to do a little bit more often, but then again, I also got into the industry back in the days when the vacuum time was determined by 20 minutes, a ton plus 20 minutes and who had a micron gage right back.

Then nobody was using micron gauges, they were doing the smoke and a half. You smoked one cigarette and half of a cigarette and that's the time to go ahead and pull it off. So yeah nobody owned a vacuum gauge back then and of course nobody used a thermometer either. It was just well your sectional.

I needed to come back beer-can cold and you charge the system until you got to the rated load amps, and that was good so, which brings up a good point that I want to address just quickly here before we talk more about oil, which is that you Need to be confirming the operation of your vacuum pump regularly. You just need to be doing that. It's a good practice before every vacuum that you pull, that you connect a micron gauge to your vacuum pump and see how deep it will pull just by itself and generally good quality vacuum pumps like the nav. A pump should pull down to about 15 microns.

If you're not able to do that, then you probably should go ahead and change your oil first as the first thing and then just make sure all the couplers and caps are all nice and sealed on the pump. Make sure your gas ballast is turned all the way down to its lowest setting and then try it again. But one nice thing about the NRP vacuum pumps made by nav app. Is they have a built-in vacuum gauge right on the pump itself, and that's a great use for that? Is that before you pull your vacuum on the system, just pull it on itself and see what it can do, and then that gives you a good indication that your oil is good and all that sort of thing.

But in addition to it, you want to look at that oil clarity as you're pulling a vacuum, because if you see a change in oil clarity, that is an indication that there may have been some moisture contamination in the system which gives you a good kind of Heads-Up of how long and how deep you definitely you need to pull this vacuum, because if you start to see some change in clarity, you know that you potentially had a contaminated system, and you want to put a little more focus on making sure that you've got That vacuum on there only deep enough, but also long enough, absolutely, and I think another area that is often overlooked is you want to change the gaskets in your hoses before they fail and not necessarily after because there's nothing worse than being in the middle of a Job and having to run to a wholesale house to get new gaskets for your hoses you're, going to spend two hours going to the wholesale house to buy a $ 3 bag of parts. So changing the gaskets in all of your fittings really is something that should be done on a somewhat regular basis, they're too inexpensive, and it's too easy to do just wait until you're in breakdown maintenance. Yeah absolutely - and we are big proponents here - of having a dedicated vacuum, rig a rig that you just used for vacuum and on that rig it's critical. I mean you may have seals that don't leak under pressure, but that do leak under really really fine vacuum, because just remember when we're measuring on the micron scale, I think my first instructor said it best.

I said you know what's a micron and he said it's exactly one that fart of pressure and so it's a very, very small measurement of pressure and so any leakage at all. It's a problem. I would also suggest just to kind of dovetail on that. You know.

I'm a big fan of using nylon and just a little dab'll. Do you, but if you keep a little bit of nylon on your seals and threads of your vacuum hoses, then that'll help kind of condition them. So that way they don't crack and fail. Quite so early, but you're exactly dead on there changing those seals and your hoses is absolutely critical, especially on a vacuum rig.

Absolutely because not only if it's leaking. It's also sucking more air and moisture back into your system, which is exactly what you're trying to avoid. So it prevents you from having to do double work all right. So let's talk about the question of the day, which is how often, should you replace your vacuum pump oil? It depends if you've got a smaller pump with a smaller sump.

You probably should change it. Every job and if you've got a job that, as you said, the pipes been out and you got caught in a thunderstorm in Florida, and I know about those Florida thunderstorms. You probably need to change it at least every job, if not once during the job. It's kind of iffy, on the other hand, if you've got a pump similar to our pumps that whoo I have about a 20 ounce sump, you may be able to do a couple of jobs without changing the oil depending on the moisture content, but it really depends On how hard you've worked that vacuum pump oil if it's discolored at all, if it's starting to go to an amber color in any way, shape or form, it needs to be changed.

If it's getting milky, it needs to be changed. The life of the vacuum pump. Oil, to an extent, is determined by the quality of the system or systems. You are evacuating, but you almost can't change it too often right it doesn't hurt to change it.

One question that a lot of guys ask is they want to do right by the environment, and so they end up changing their pump oil, and then they don't know what to do with it, and I ever think of what is a pretty practical suggestion. If you're using smaller canisters of vacuum, pump oil, then what you can end up doing is just save the older canisters and then you're just basically doing a swap when you pouring in on the top, then you're draining out into a funnel on the bottom side, with An older canister and then you just seal that canister off and then I've never figured out whether or not this is technically correct or not, but this seems to work just fine. Most auto parts stores have a used or old oil container there and I've never had anybody complain about you using that. I guess I should ask you: do you have any opinion on that? Is that a good place to dispose of oil? Well, that's one place to dispose of it.

The other thing is, since I'm sure a number of our listeners are in areas that actually require heat. Unlike Florida, a lot of gas stations will have clean burn furnaces and they will actually burn their used. Motor oil to heat, the gas state or heat their service bays in the wintertime, and that's another place that you can dispose of it. The third and probably least, preferred is to save the oil containers and I think that's a great idea.

I hadn't thought of that. I always told guys to use a coke bottle or something like that that they could seal off. The third would be to take it to your local waste disposal center whenever they're collecting things like used oil. So there are certainly ways to dispose of the oil in an environmentally friendly way, and it's very important to understand that one oil change worth of oil will contaminate hundreds of gallons of ground water.

So the last thing we want to ever think about doing would be to actually just drain it out onto the ground yeah, it's one of those things that I think we have to just sort of address, which is that there were a lot of bad practices back In the day - and I'm sure we all work with somebody who did that sort of thing at one point in time in our career or another, that doesn't mean it's okay and the way to do it correctly is really no big deal in the same way that You keep an extra jug of water on your truck, so that way you can clean the drain line or whatever you're just going to do the same thing with having an extra canister with a seal top that you either recovered once you actually empty that canister out In the used oil tank or wherever you go now, you've got it and just put it back on your truck and so the next time when you do the swap that's easy to do so. I think it's important that we always address the practices here. It's very practical to do and if you get used to doing it regularly, then your pumps gon na last a lot longer. You're gon na pull a lot deeper vacuums and you're gon na be much more assured that you are doing the right thing.

As far as the environment, if you are prepared to dispose of your old oil in an appropriate way, but I like what you said you want to think about the application, and then you also want to think about the oil capacity of your pump. So talk a little bit about that because I know there are some different types of pumps and different oil capacities and how does that impact the biggest advantage to having a larger sump? As I see it is that you can absorb more moisture out of a system. It lets you be off doing other things, while you are evacuating and not wondering whether your oil has lost its ability to seal that pump or to lubricate the pump motor. So by having the larger sum, we feel that it keeps the pump running a little bit.

Cooler, it keeps our oil fresher longer giving us a longer seal and we aren't having to stop an evacuation in the middle to change oil. One thing about navicomp, that's interesting is that they have a solenoid inside and I think a lot of text may not really understand what the value of that solenoid is. I shouldn't say: I don't know that I said all of them have them, but the common ones that are currently out there for the HVAC industry, the NRP versions, have this solenoid talked a little bit about what that's for the idea behind the solenoid is that if You inadvertently lose our to your vacuum pump. Let's say: you've got a big system, you want to evacuate it and you don't want to hang around because you know it's going to be ours.

It allows you to leave and if some other worker on the site decides he's going to pull your plug because he needs power to run and saw that solenoid will close and stop you from losing your entire vacuum. It's about the equivalent of a manual shutoff valve on everybody else's pump. The difference is that as soon as the power is either turned off or lost that solenoid shuts instantly and it preserves the integrity of your vacuum. The solenoid in the vacuum pump is a electrical solenoid.

That is normally closed. So if you lose power to the vacuum pump or somebody turns it off inadvertently that solenoid valve closes and you will maintain the integrity of your vacuum and you won't be sucking in air and moisture that then has to be removed again. The other function is it stops the vacuum pump oil from being sucked back into the system. Should you be under a deep vacuum at that point and everybody's had that issue? If they've had power cut to their pump, where they look and there's oil all over the place, it prevents the mineral oil from being sucked into the system, because the mineral oil and particularly pol, are not compatible, and the last thing we want to do is introduce More contaminants into our system and that solenoid valve will prevent that from happening.

The solenoid is located just below the tree and the vacuum sensors that we have inside our vacuum pumps, so you're still going to be able to read vacuum, even if that solenoid is closed. When the pump is turned off as well yeah, which is a really nice feature, because whereas a lot of pumps will have a manual shutoff valve, obviously you didn't intend to lose power. So you're, not gon na, be standing right. There ready to shut that valve off.

With the solenoid, if you do lose power, it automatically closes, it goes normally closed. Like you mentioned, it's a really nice feature give us a quick overview of some of the navicomp that are on the market and some of the great features that are in these pumps. One thing that we've done - and you mentioned it earlier - is we've gone to a DC. Inverter drive motor, and this does a couple of different things.

First of all, it allows us to control the speed a little better. It also allows us to remove the AC winding in the pump which allows us to save about six to eight pounds, maybe a little more depending on the manufacturer of our competitors pump. So both our six and eight CFM pumps are only twenty five pounds. Another thing that we do with our higher-end pump is we actually have a two-speed motor as well, because one of the things everybody feels like they need the vacuum pump for those of us that are of a certain age is the Tim Taylor mentality, which is more Power what we have done is we have taken our pump and when we get down to five hundred microns on our internal sensor, we then go into a degassing speed, because having a big pump is great until you get down to that low vacuum, and at that Point it almost doesn't matter what size your pump is, because you can only pull so much moisture off the walls of the inside of the tubing at a time.

It isn't where a 16 CFM vacuum pump is going to pull all the moisture out of my 6,000 BTU reach-in cooler system in a hurry. If you go too fast, you can actually freeze that moisture to the walls of the tubing. Then you think you've got a vacuum until you do a standing evacuation test, and then you discover that micron level is rising and that's because the moisture is actually thawing and being released back into the system. Yeah.

It's sublimating changing directly from the solid state to the vapor state inside that system, and you see exactly what you just mentioned there. I think a lot of the hype around the high CFM pumps, for our industry at least has been overstated. It's a lot of these other features that we're talking about here that make a huge difference in the operation of the pump in even in your vacuum. Rigs.

Things like the seals and the size of the hoses and the length of the hose is that you use and all those sorts of things is a lot of what we're learning and for most of us, a six CFM vacuum pump or an 8 CFM vacuum pump. Those are kind of right in the sweet spot, depending on the type of rig that you use of doing a great job in the operation. Absolutely and the biggest mistake that a lot of technicians make is. They do not use dedicated vacuum hoses, which don't have the Schrader depressors in them, and they don't remove the Schrader course those restrictions, especially when you start getting two or three of them in your rig, and really impede your progress when it comes to evacuation.

I can't overstate enough that you need to remove the Schrader course and you need to have dedicated vacuum hoses. The other reason for that is that regular hoses are made with a permeable cover so that they don't explode. We can get to some pretty high pressures pretty quickly if we aren't following good practices and those hoses are designed to fail sort of gradually. So there isn't an explosion or sudden burst of the hose.

And, of course, what can come out sometimes can also get pulled back in so again having the right setup is more critical for evacuation speed than the actual size of the pump. Let's talk a little bit about the built in micron gauges. Cuz, there are some. I don't wan na say it's controversial, but it's a question that a lot of technicians ask as soon as they see that their firsts are like, oh that's great, and then they think well wait! A second haven't.

We been learning that we don't want to pull or we don't want to measure our vacuum at the pump that we're supposed to measure at the equipment. So what are your thoughts on that? There are a couple of number one. You've always got a micron gauge. I think it's really handy to have that second micron gauge again going back to back.

In the day, we actually built a tree on the entrance to our pump that it was where we put our micron gauge. Obviously we're doing the same thing here. What this really is doing is it's giving you a micro engage that you're going to have all the time now. Is that a vacuum going to be exactly the same as it is at the far end of your system? Probably not, but when you go into a standing vacuum test that evacuation or that vacuum is going to equalize out, so the equalization numbers are going to be the same regardless, because any moisture at the far end is going to travel to the near end.

So well, it is not the same number. While the pump is running, it will be pretty close to the same number as you're doing your standing vacuum test. Okay, that brings up an interesting question, a question that I don't know the answer to, where is the location of the micron gauge on the pump in relationship to the solenoid valve on the pump R? Is the micron gauge above the solenoid in the tree or is it below the solenoid it's above the solenoid in the tree? It is right below the intake or hose connections. If you will of the pump, you have your vacuum sensor there and then right below that.

You have your solenoid, so you would actually then potentially just shut off the power. Then I'm thinking of the NRP, e8 or 6di you'd hit the power button on the side of the pump and then that's how you would do in your standing pressure test. At that point, yes, when you turn the power off using the power button on the side of the vacuum pump, you are at that point starting your standing vacuum test. One thing I would mention is you will see the numbers rise fairly quickly at the beginning, and that's because that vacuum gauge is going up in single-digit microns, so it can move pretty fast and you've only gone up 30 or 40 microns.

One of the things I did want to address that occurred to me earlier, as we were having our conversation is that knowing the micron level you're pulling down to is extremely critical at this point in time, you could get away with a lot of things back in The day when we had inefficient systems and inefficient charging methods kind of again going back to that beer cane cold on the suction line for your air conditioning system thing now, with the 410, a systems that everybody is using, the various other refrigerants having seer and EE Are levels well above 13 or 14? We are at critical charge systems and it's really important. We get all of the moisture out of the system, because we've got very small orifices. In many cases, we're now using variable orifice sizes in particularly ductless split systems, where we've got our metering device that opens and closes in a very large number of steps. Those orifices get really really small.

Any moisture left in the system can start to clog those or can constrict those. So it's really important that we get all the moisture out and it's very important that we verify what our vacuum is. So we know for a fact that there's not any moisture in there and having our micron gauge in the pump gives us if nothing more, a second place to look at the evacuation. We are actually pulling my way of thinking about it is that if you've been doing things the right way for the last bit of time, which I think a lot of us have learned a lot over the last few years, especially as pol came on the market And, like you mentioned ductless systems, there's a lot of things that are coming out that are getting more and more critical.

You already have a micro engage in your truck. You should already have a micro engage at your truck, go ahead and put that at the system, and now you get another one at your pump and now it gives you two data points and not only gives you two comparative data points and they're, not gon na Measure exactly the same micron level micron is a very, very fine measurement and so you're never gon na find two micron gauge that read exactly the same micron level. But it's going to give you an indication of not only the pressure drop across your rig, which is useful information, because that's gon na tell you potentially you have a rig leak or a visit doesn't have full flow or whatever that's one good data point. But then, when you do the standing pressure test, like you just mentioned, that's also another good data point that you can potentially use, and so there just gives you more options, and it also gives you something to check against plus it makes it really easy now, for You to confirm your deepest pump, only vacuum right when you start the thing up, you just put your caps on turn it on.

It shows you how to deep vacuum. It pools right on the on-board micron gauge, which is extremely useful. So all in all, I think it's a great thing. I love the solenoid, I love the DC motors and the pumps.

I love how quiet they are that's an excellent piece. There is that they're not gon na annoy anybody with their noise levels which, if you're working in a subdivision, sometimes that can be a challenge when the houses are right next door to each other. And you don't want about the neighbors and there's a lot of different features with it. Also another thing with the DC motors is they're less susceptible to voltage drop.

Now it still matters, you don't want to have low voltage is applied, but it's gon na work. A little better, if you say you have a long extension cord or maybe your voltage isn't quite what it should be. That's another nice thing with those DC motors absolutely and getting back to the pump with the micron gauge that's built into it. That is actually a two-speed pump so that, once you reach a certain micron level, that's pump will drop down to a lower speed and that will really enhance the degasing phase of the evacuation, not very nice, and I didn't even realize that part.

So it's a lot of good things to think about all right, so to finish up here. These pumps that we've talking about today, specifically the ones with the solenoids and the micron gauges, and all that they are made by Nav Akande out more at Navajo Bolcom. But I also wanted to mention that you can find all these nav act: pumps at Tru tech tools, com, that's t, ru tech tools, com and, if you use the offer code, get schooled, you get a great discount. Let's get schooled, no spaces, no caps and then also and just to keep adding it on it's like, but wait, there's more.

Who can they have a chance at winning? One of these really nice n RP 8 di pumps with the digital micron gauge built in it's sort of the flagship of the fleet. Right now you can win one of those by entering at HVAC our school comm. Four slash nav act, that's HVAC our school /a fact there is a giveaway there. You get some extra entries if you interact with Navigon social media and do a few actions.

So you can get some extra entries increase your chances of winning by doing that, and that is a really good giveaway, because that's an excellent pump and something you're gon na be very happy to have on your truck. Even if you get another one, you can make your other pump, that you have your backup and make the nav a clump your primary, so those are all opportunities to get a chance to interact with nav act. Like I said, I have tried them out a couple. Different times you have a couple of them out there in the field Tech's using them, they love them.

I had a guy try to steal my shop unit. I was using for demonstrations. I had to catch him walking out of the shop with it. You had a mischievous look on his face, so he knew what he was up to, but anyway yeah they're, excellent, excellent pumps and I think you'll really enjoy them and Kevin.

Thank you so much for sharing your knowledge. I really appreciate it and I know we're gon na, have you on again very soon well, thank you Brian. I certainly enjoyed it. I look forward to talking with you again soon all right.

Thank you, sir goodbye all right. Thanks for listening to the HVAC school podcast, just another quick run-through of our great sponsors that I'm very thankful to carrier and carrier comm, refrigeration, technologies makers of all that great stuff, that I always talk about. Like big blue, the soap bubbles at refridge, techcom, air, oasis.com, /go for great indoor, air purification products, uei test comm for the hub six kits and then of course, nav AK. The company we were just talking to thankful to all those sponsors should really do keep the lights on the hypothetical lights on here at HVAC school.

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