How HVAC Manifold Gauges Work & Why You Shouldn't Cheap Out On These!

in this video we're going to be talking about HVAC gauges now these are extremely valuable and versatile Tools in checking the refrigerant levels and pumping down a system to where we can contain all of that refrigerant into the condenser and I want to talk to you today about how these work what's inside them what is the purpose of the manifold and these different knobs we're going to talk about the smart gauges as well and equally as importantly I'm going to talk to you about hoses and why hoses are so important as well so let's get right into it all right so the basic premise of a manifold set is so that you can one read your pressures that's what these gauges are for and two we have the hoses to where we can connect these to the actual unit now if you've seen my previous videos uh you'll notice that we have the blue side going to the low side service port red will go to high and this yellow hose is what will go to like a vacuum pump or to a refrigerant tank and this yellow hose will allow you to feed refrigerant into the system through this hose and out these two hoses now that brings us to the purpose of these knobs now when these knobs are closed basically nothing is allowed to go in or out of these hoses so before I get into more depth about this I want to explain something so pretty much on any residential split system with the exception of like mini split systems some of them only have one of these but pretty much all of the systems that you'll see on a residential regular split system will have two service valves this is your high side so what's happening is the compressor is pushing refrigerant out of this tube and it's sucking it back into what they call the suction side or the vapor side so it's pulling it in and pushing it back out now the misconception that I want to clear up is while the system is running the whole system has pressure and so it's not going to be pulling anything through here it still has pressure but even though the system is under pressure it's a constant Loop going through the evaporator coil back into the compressor and it just keeps making this Loop and so when we say suction side this is still under pressure typically this line will have 100 between you know 120 to 140 PSI and the high side will have somewhere around 300 to 350 PSI later in this video we're going to show how to connect to the AC unit properly and how to remove your gauges as well this video is brought to you by jobber jobber is an excellent CRM or customer relationship management system AKA a system where we do invoicing estimates we keep track of all of our customers there we can keep pictures of units and everything separate from our personal information and for me what I find most important about this software is that we can do monthly reoccurring payments for service plans so I have many customers that we do service plans or service agreements with and it's x amount of dollars per year for that service plan which includes two visits but it's broken down into monthly payments like fifteen twenty dollars a month and it auto bills the customer so I don't have to worry about sending an invoice and I have a steady monthly income even during the slower months as an HVAC Tech if you'd like to find out more about jobber or sign up for a free 14-day trial check out the link in the video description and you can find that there okay so now if we look at this manifold if you look right in there you can see a hole on both sides so what happens when we turn this is that it's going to allow this pressure even though it's the suction line it's still under pressure it's going to allow it to go through here and to go whatever to whatever this hose is connected to or vice versa so let's say for instance we have our yellow hose hooked up to a refrigerant tank now even though the system is running and we have say a hundred and whatever PSI the pressure in here is going to be greater up to a certain point once this tank gets to a certain below a certain pressure it will not feed into the system any longer but as long as there's more pressure in here we will use the compressor to basically pull the refrigerant when we open this it's pulling it through this hose through the manifold and into the system and then as soon as we close it we're isolating this from this and that will stop the flow of refrigerant from going into the unit now we'll get into this more once we actually connect these gauges to our our AC unit so you can get as fancy or as basic as you want with your manifold set and this does matter to an extent if you're not wanting to spend a ton of money I'd recommend getting a good CPS or yellow jacket a simple gauge like this I'll tell you why these cheap ones are not good if you're just getting this to pump down a system that's totally fine but I want to show you what these little dials and all these numbers mean inside of here and how they're not accurate on these cheap gauges so let's take for instance this CPS gauge on the low side um we have pressure in here just from the last unit I was hooked up to but if you look at the 50 and where that correlates to on this pink scale we're at zero degrees this inside scale for 410 or for 22 that's the degrees that's your evaporator coil is going to be at whatever pressure you are here so if we went up to like 150 we'd be close to 55. let's look at the other gauges and see what they read at 150 we should be at 55. but if you notice here if we take this last scale down which is the blue one we're at 150 this shows 10 degrees not even close so if somebody was trying to measure their superheat or their sub cooling with this manifold set it would not work at all it wouldn't even be close so I don't recommend getting a super cheap manifold set spend a few extra dollars on a CPS a yellow jacket JB Industries is another good brand field piece you don't necessarily have to spend you know five six hundred dollars on one like this but you can still get a quality manifold for under 200 now if you're wondering about these probes there's different methods to checking the temperature of the copper line set that's how you measure the superheat and sub cooling is with a clamp like this and a digital meter or for the nicer gauges you just clamp this onto your pipe and this tells you your sub cooling and superheat now if you'd like more information on how to find your sub cooling and your superheat I highly recommend this book by Craig migliacci he has an awesome tool here as far as checking the superheat the target superheat chart and actually the procedure on what to subtract from what to find out your superheat I highly recommend this book if you're looking to gain more knowledge whether you're a diyer or you're getting into this field so if you want to find this check out our Amazon store now just so you know having a manifold set is much more versatile than just having it for your central HVAC system you can buy these adapters and you can check the refrigerant charge do a repair on your vehicle and you don't have to buy a whole other gauge set you can just buy these so if you're buying a gauge set that you want to work with both systems make sure that all of the fittings are quarter inch not 5 16 because if they're 5 16 it will not work on a residential system okay so let's talk about hoses for just a second I want to just explain this real quick so if you get your hoses separate with a lot of a lot of kits come with them separately they're not already attached make sure that you connect the end that doesn't have anything to this bottom Port that goes into your manifold now I'll show you on the back side what they have on pretty much any manifold you're going to have three ports or some some manifolds have four ports and they actually have a hole that goes up into the manifold then if you look on the back side you have three dummy holes so there's nothing this doesn't go to anything but it's just acting as a place where you can store these hoses when you're not using it I'll show it to you on this field piece these are the dummy ports as you can see there's nothing in there and that's just used to store this these are the actual ones that go into the manifold now the reason I mention that is if you put these on backwards you notice that these have valve stem depressors if you have these connected here then when you go to connect this side to your AC unit let's just say for instance you have this reversed this would not push in the valve stem at your service valve and you wouldn't read anything on your gauges so make sure you have these oriented properly now I want to talk about these for a minute when you hook this up to your unit it's going to let out some refrigerant when you connect it and especially when you go to remove this all of the refrigerant that's in your hose is going to be let out into the environment now the EPA recognizes that if you have these old school ones or not fancy ones that's going to happen as long as you're not intentionally letting out a ton of refrigerant but the advantage to these These are low loss fittings and if you can see down in there they have a special apparatus that when you take this off it just lets out a little tiny Spurt of refrigerant not much at all and I actually didn't realize that these were low loss fittings they looked like regular fittings they're much more compact if you look at my old manifold set notice how much bigger these ones are this is what the old yellow jacket ones used to look like they're very bulky but the new ones that I'll leave in the video description are like these and they're very Compact and they work extremely well so let's head out to our condenser and we'll show you exactly how to connect your manifold set and how to read the pressures on your system all right so before we connect our manifold gauges to the AC unit always make sure that you have gloves on if you haven't done this before um even ones that do have a lot of experience should probably wear gloves I'm guilty of not doing that all the time but if you do have a valve stem that wants to stick and refrigerant comes spewing out that doesn't happen often but these give you an extra layer of protection it's always recommended with when you do anything involving refrigerant to have your EPA license I'm going to do a video very soon on how to get your EPA license so stay tuned for that but I just want to show how to connect your gauges so what I'm going to do you can you can hook up your gauges while the unit is running if you want to but because it's kind of noisy I'm just going to pull the disconnect here and I'm going to show you with the system off how to do this so we're just going to start by removing the caps sometimes you'll have metal caps here you can grab a pair of pliers or an adjustable and loosen that there is no refrigerant behind the Caps as long as your Schrader cores are not leaking or anything you don't have to deal with these King valves just these two service ports here so it's very simple um we're just simply gonna take our low side off of this dummy Port right here as you can see it doesn't go anywhere I'm just going to make sure this one is snug and we're going to attach our blue line to the vapor line or the low side there's different names for these but I call this typically the low side or the vapor side this is called the high side or the liquid side so we're just going to do this pretty quick with our low loss fitting and as you can see nothing came out when installing it when we take it off there will be a little Spurt of refrigerant now if you were charging the system if you're going to be using this yellow one hooked up to your your tank you would want to burp all three of these lines because as soon as we connected this this had air in it and that refrigerant pressure pushes it up and compresses the air to right here so if you're going to be charging the system or adding refrigerant you want to burp all three of these I'll show you how to do that real quick it's very simple you just crack this line for about that long and that's what's considered burping that line so we're going to do the same with our high side and we're just going to hook it up to our high side here now one thing with the low loss fitting that I was taught is when this seat you want to back it off just a hair if you go all the way you can supposedly shorten the life of this so as soon as it seats back it off just a smidge and you'll be good to go and you'll save your low loss fitting Hey booger what you doing I'm gonna learn about AC so we're going to go ahead and turn our unit on and we'll do a little bit of explaining on our pressures here so we're going to let our pressure stabilize let this unit run about 10 minutes before you check your readings again we're going to do a separate video on how to check your superheat and sub cooling to make sure that your HVAC unit is charged to the proper level and that you're getting the most efficiency out of your system so if you look at your low side here this is a 410A system so we're going to follow that dial we're at about a hundred and 120 ish PSI and see what it correlates to on your scale that's going to tell you your indoor evaporator coil temperature okay so before we disconnect our gauges I want to point out one other thing a way that you can tell without having to go inside what your metering device is is if this needle is moving up and down real slowly that tells you that it has a TXV or a thermal expansion valve and what it's doing is it slowly allowing more refrigerant and less refrigerant into that indoor evaporator coil that's how you can tell just off your manifold if you have a TXV but if you notice on mine it's just pretty much stayed at 39 degrees or at whatever pressure this is that's a good way to indicate that this is a piston type system so just a little bit of extra knowledge there now when we disconnect our gauges the best method of doing this is to disconnect the high side and then we're going to let our pressures equalize so that's going to transfer all of this refrigerant from the high side hose into the system and then you're gonna not be having all of this refrigerant in the hoses when you disconnect it so what we're going to do is we're going to disconnect your high side now with these low loss fittings you want to do this pretty quick and you'll notice how little refrigerant comes out when I do this that's it that's the advantage to having these low loss fittings so now that I have my high side off I didn't show this but I I did go ahead and burp this line just so that nothing is no air is trapped in here same thing we just let a little bit out so if there's no air in this system what we're going to do is we're going to open the high side and we're going to open the low side and what that's going to do as you'll notice the high side drops to the same pressure as the low side that's letting all of the refrigerant from this hose into the system through the low side port and as you can see now instead of having 350 PSI of pressure in this hose we only have about 130 using this method will allow you to keep that refrigerant in the unit and not waste it okay so now that our pressures are equalized we're both sitting at about the same pressure we can go ahead and take off our low side you see that barely had a little tiny spurt and that was it so it's as easy as that to connect your gauges and remove them and another good common practice is not to leave pressure on your gauges again I'm guilty of this but pretty much all you do is just let out whatever's in the hose if you don't let out um if you don't equalize the pressures like we just showed you letting out 350 PSI out of this hose you'll notice how much liquid refrigerant gets trapped in these hoses and that's definitely wasteful so now as you can see we're out of pressure and we can store our manifold well guys to sum this up I highly recommend getting a decent manifold set if you want to have one to use on your HVAC system on your vehicle you saw the advantages in having accuracy in the readout here and then in addition to that if you can get these separately or as a combo I highly recommend the low loss fittings you can find those on our Amazon store simply go to the video description below click more and then you'll see my whole Amazon store there where you can see a different selection of all these tools that I highly recommend I just want to make it clear that if you're doing anything with refrigerant make sure that you're going through the proper steps and channels to get your EPA license before you mess with refrigerant I know some people will comment on that but if you have your EPA license you are legally allowed to check this to buy refrigerant a lot of people don't realize that abilityrefrigerants.com sells refrigerant to the general public you have to check a box saying that you have your EPA license or that you're reselling refrigerant a lot of people don't know that they can purchase refrigerant now if you've just purchased a manifold set and you want to measure your superheat or sub cooling to make sure that your system is charged properly and getting the most efficiency check out this video right here and we're going to walk you through how to get your target sub cooling or superheat and how to measure that and make sure that your system is running optimally and we'll show you areas to look if you have something that's causing your superheat or sub cooling to be off until next time you guys be safe later

Channel: The DIY HVAC Guy

Views: 73,810

Keywords: how to, air conditioning, ac gauges how to use, manifold gauge, yellow jacket, hvac training, gauge manifold set, how to recharge your ac system, air conditioner gauges how to use, ac system recharge, recharge ac system, hvac troubleshooting, hvac training videos, hvac technician, air conditioner, manifold, hvac manifold, hvac manifold gauges, manifold gauges, fieldpiece, cps, jb, ac manifold gauge set, how do you, ac service tech, diy hvac guy, diy, a/c, air conditioner repair

Id: hOq9XuJ4OWA

Length: 20min 2sec (1202 seconds)

Published: Thu May 25 2023