This video is brought to you by Sporland. Quality integrity and tradition. All right. This morning we have a call. Actually two calls. I Don't think the customer realized what's going on, but this waitress reaching in this bar region they say are not working. sounds like the condensing unit's running, but they actually put in two separate service tickets. but they actually have the same condensing unit. So let's open this up. I'm waiting for management to get here. they're not here yet so just kind of deal. What? I Can tell they get here, got the cover pulled off and so the compressor is running. It's warm and it has like a cool suction line. but if we come down here, sight glass is empty. Um, this unit has a head pressure control valve so it requires extra refrigerant to flood the condenser during low ambient conditions. but we're more than likely you can see glass is empty. It just has tiny bits of liquid. So I'm gonna go get some refrigerant. Uh, we're gonna top off the charge I Don't see any signs of a leak up in the condenser. so that's why I Feel safe topping off the charge. More than likely there's going to be a refrigerant leak down in the evaporator sections because the waitress reaching especially. they keep salad dressings and it just gets airborne and destroys the coils. So we'll top off the charge, get the proper charge in this guy, and then go downstairs and find a refrigerant leak. So yeah, this guy definitely looks like it's low on refrigerant and we know that because the sight glass is flashing. so we're gonna. Purge I've got some 404a right here. We're gonna go and dump it into the low side. Now this system is more than likely just low the winter charge. but we'll see. we'll see how much it takes to get the system back up to normal operating conditions. So as I'm charging this, let's talk about this. So I'm slowly metering it in I actually moved it from the suction service valve to the suction filter dryer because it's going through a Schrader and then it goes into an accumulator. So I can charge it a little more aggressively. It could be a few Motors grabbing most of the liquid and boiling it off before it goes to the compressor. But I'm listening to the tone of the compressor as is accepting the extra refrigerant. So I said something in the beginning that I bet you anything this unit's only short in the winter charge and how we'll know that is if um, if it only takes like a pound or two to. all of a sudden Boom the sight glass clears up. That's typically that it's just short the winter charge. So what's happening is we have a head pressure control valve on this. The head pressure control valve is trying to simulate a warm day because the expansion valve downstairs it's a thermostatic expansion valve. It doesn't work as good in low ambient conditions. so we have an artificial. We have a valve that artificially increases the head pressure by flooding the condenser, but in order to do that, it requires extra refrigerant. So our Head Pressure Control valve will bypass at about 180 PSI So anything below 180 PSI the head pressure control valve will open and bypass the condenser, which then backs up refrigerant in the condenser and then it shoots refrigerant into the receiver assuming that the receiver has the proper flooded charge in it, those liquid refrigerants sitting in the bottom of the receiver and it's forced out down to the expansion valve so we still have a saw solid column of liquid going to it in our case, right now, we do not have a solid column of liquid going to the expansion valve, therefore it cannot work properly, so we just keep adding some refrigerant and seeing where that gets us. If you want to learn more about Head Pressure Control Valve charging, there's a couple different methods of doing so. Uh, go to Sporland 90-30-1 Just Google Sporlin 90-30-1 on the Internet and you'll come up with a Head Pressure Control Valve Charging PDF document and that'll help you guys to understand how to properly charge these systems and why they need to be charged and sized appropriately. So I was incorrect. It is not just short the winter charge because now that we're at 192 PSI the head pressure control valve should be shut and we're still flashing at the sight glass. So if when I got above 180 all of a sudden, the sight glass cleared like that, then that would indicate that it was just the winter charge. But no, this, this has a significant leak because it's low. extremely low on refrigerant, so still adding it just moving along. Management still isn't here yet. So I just keep Uh now I did come on the roof. They do know me and they do. They are okay with that, but I'm still constantly walking over to see when they're here. So that way I can give them a call. I'm assuming they would see my ladder, but you know I'm not just going to stay up here all day without telling them, you know? So of course, when they get here, I'll go down there and talk to them and then we'll go down and leak check the evaporators. all right now we're violently flashing so we're making. Headway We're actually getting somewhere so we're gonna keep adding refrigerant. We're looking for a Clear Sight glass, but just a Clear Sight Glass isn't enough because then we have to add the winter charge after that. All right now. my com: my sight glass just cleared. Okay, my sight glass cleared. My head pressure is above the bypass pressure of 180. PSI But even though we have a clear sight glass, we still need to add extra refrigerant, the winter charge, or the flooded charge. Okay, there's a couple different methods to do this. I Said check out Spoilin 90-30-1 That'll tell you how to calculate the internal volume of the condenser. So that way you know how much extra refrigerant to add for the flooded charge. One of the easiest ways to calculate that flooded charge is to lean on the manufacturer. Now these are Tecumseh condensed units and they do a really good job on these older ones with the model number and there's a a pamphlet in here and on this pamphlet, you find your model number, you follow it over, and you find the minimum ambient temperature. Okay, so we're gonna use 30 degrees Typically doesn't get any colder than 30 degrees here, so 4.2 pounds is the flooded charge. Now we are going to add 4.2 pounds on top of all the refrigerant that I just added and then our system will have enough refrigerant for when the temperature gets down to 30 degrees, So that way we can still have a solid column of liquid going down to the expansion valve and the condenser can properly flood. Okay, now on another note, you know it's a possibility that maybe we might dip a little bit below 32 or 30 degrees, right? So look at that. it's really not a huge difference. 4.2 pounds. Or if we put four point Sorry or if we put 4.4 pounds in the system, we can get down to 10 degrees. Okay, so I think I feel a little more comfortable putting an extra 4.4 pounds in there just as a safeguard and we know that we will be able to properly flood and maintain a solid column of liquid going to the expansion valve all the way down to 10 degrees. So 4.4 pounds is where we're going to go on this bad boy. and I'm gonna go get a scale right now and I will weigh in the difference All right. I got my scale and I added the extra 4.4 pounds. So now we know that this system has enough refrigerant to keep a solid column of liquid, a Clear Sight glass going to the expansion valve all the way down to 10 degrees outside ambient temperature. All right. So at this point what we're going to do, the next thing we need to figure out is if the system has too much refrigerant in it. Okay, just because the manufacturer says to add the extra 4.4 pounds of refrigerant in there doesn't mean that the system is designed for that much refrigerant. Because one thing the manufacturer doesn't know one variable that we as a technician or contractor have that we can control that could hurt this condensing unit is how long our line set is and how many evaporator coils are running off of our system. Okay, now this is an outdoor condensing unit. It has a massively oversized receiver. I Don't doubt that that receiver is properly sized, but let's go ahead and check it. so in order to properly check it, what we're going to do is we're going to pump the system down and we're going to check the liquid level in the receiver. now. I've already opened the packing on this. You can see that I can clearly turn the packing. You want to make sure that those things are open. it. Uh, it's it. Basically extends the life of the gaskets in there, so that way they don't wear out. Okay, so you loosen those before you actuate the valve and then once you loosen them, you tighten them back up because they do tend to leak. Okay, so we are now pumping down the refrigerant in the system. We stopped the flow of refrigerant at this King valve. This is a king valve. This is the only King valve in the system. A lot of people get that term incorrect. The king valve is on the outlet of the receiver. Okay, if there is a valve on the inlet of the receiver, that would be the queen valve. All right. This right here is not a king valve. This is a suction service valve. Okay, and every other valve is just a suction service valve. A liquid line service valve. This is a king valve. Okay, so I closed the king valve. We're pumping the system down. The refrigerant is no longer leaving the receiver via the king valve. It's stopped, but the compressor continues to pump and it's pulling all the refrigerant out of the system via the suction line and then it'll shut off on low pressure. Now here's something that we have to consider and be careful about. We do not want the system to pull into a vacuum because we know we more than likely have a leak on the suction line or the liquid line downstairs. I Don't think we have a leak up here because I don't see any signs in it, but there's always a possibility. But if you have a leak on the suction side or the liquid line after the king valve and you pump the system into a vacuum, theoretically you could pull air into the system. Okay, so we're waiting for the system to pump down. We're making sure that there's enough room in the receiver and we'll also check the liquid level once it pumps down. It's very important to have a high side pressure port on this side of the king valve. so this right here is the inside of the receiver's pressure. If I put the service port right here on this liquid line, it would actually be pumping down right now. so you want to make sure you either have it on the discharge line or on the the receiver side of the king valve. So that way you can actually see the system's high side pressure. Okay, because that's a good indication of an overcharge if the high side pressure just skyrockets. All right, we're about to pump down and then we will, will, uh, check the liquid level. All right. I Was able to take a heat producing device and very carefully heat up the receiver and we can clearly see that the liquid level. You can see my fingers right there. The receiver starts to get warm about right here. Okay, that is about the three-quarter level of the receiver. You can clearly see the temperatures right, and you can see how you've got the orange, the purple and it gets warmer and warmer. But the actual point where it gets really warm is right about here, right? So using that that right about here. there's actually already a mark right there from one of us. now. I'll remarket with the yellow paint marker, but that is indicating that with the proper amount of refrigerant in the system, we are not. We're not even actually at the three quarter Mark We're a little bit below I'd say the three-quarter Mark is about right there. so we're about two inches below that. That is the maximum. The three-quarter mark would be the maximum amount of refrigerant you could ever put in the system because you have to have room for expansion. You can't fill that refrigerant storage vessel all the way up because refrigerant reacts to temperature. The hotter it gets, the higher the pressure goes. You need to have room for that refrigerant to react to the temperature, and you don't want a catastrophic explosion so you don't ever want to overfill these guys. And that's why I Said the manufacturer doesn't know how long the line set is right. They just tell you that with a solid column of liquid a Clear Sight glass above the bypass pressure of the head pressure control valve, you add an extra 4.4 pounds of refrigerant right to charge the system for the flooded charge or the winter charge. But they don't know how long the line set is and the line set length determines how much liquid that system can store when I'm pumping it down at the receiver. We're taking the system's storage out of the equation and we're storing all the refrigerant in the receiver in the condenser. So that's why you have to be very careful and always make sure you have high side gauges in a good spot. That way you can monitor the high side pressure of the system and know if you're going over the high pressure limit of the system. Okay, so now we know and I'll mark that and then we got to go downstairs. We'll put the system back in operation, then we'll turn off the condensing unit, equalize out the pressures, and we'll go down to the evaporator, shut them off and do a leak search, and try to find out where this refrigerant leak is. All right Now I Have shut off all the refrigerant or the system right and we're going to equalize out the refrigerant within the gauges, right? So I shut down the system system. The solenoid valves and the evaporators downstairs are more than likely still calling. They're still flowing through. but now I equalized out the pressure. So that way we have equal pressure from the high side and the low side in the system and we can properly search for a leak. Now do a quick little inspection over here. just listening, not not hearing any refrigerant leaks over here. Necessarily okay, but we're not going to Discount that there's not a leak over here. but I I checked it I don't feel like or hear anything I don't think there's a refrigerant leak up here I Strongly believe it's downstairs. so we'll go get the electronic leak detector and go down there and uh, see what we can find. All right, my leak to text is already picking something up. Going crazy in there. This is the Fieldpiece Dr-82 going crazy in there? Wow. Okay, so we we've got something going on in here. Let's go look at the bar regions. We've got some bar regions over here. Go to the bottom of the reaching you'll typically so now I do have it set on turbo, so moving it around too fast we'll get some extra sensitive readings. But I don't think there's a refrigerant leak in here if you get a something something, but then it goes away. I Think that's more or less just because I moved it fast now. Gretton Again, like I said I have it in Turbo which is the most sensitive way. So I don't think our leak is in here. So we're gonna go to the other bar cooler because there's another one. This is the other bar cooler. do the same thing down in the bottom. nothing. The refrigerant is typically going to fall. We'll go up here to the evaporator, so this seems like a pretty significant leak. I Don't think it's going to be in here either. So I don't think it has anything to do with the bar coolers. and again, the bar coolers typically aren't where the leaks are because they don't really keep uncovered. Um, vinegar-based uh, dressings and citrus based things in here. I Mean, they might keep some lines in here, but that stuff will all attack the coils. These coils look pretty good, so let's go focus on the waitress reaching coils and I'll turn these back on. All right. So if we come in here, honestly, it might just be the power heads. A guy's popping off somewhere in there. or is it coming from back behind the coil and it's not going off in there? Let's go over to here. It's not going off in there. Oh no, it is. Yeah, it might be in the coil. We'll get some. uh, big glue on that powerhead. the power head. You definitely see that green stuff that's from the salad dressings being uncovered. But overall, this coil is coated so it seems like it's a little bit in decent shape, but we clearly have some leaks going on in there for sure. So let's get some big blue soap bubbles on it. All right? It doesn't seem to be coming from the TXV I've got big blue soap bubbles all over it. What? I am seeing is inside the coil now. I Sprayed these bubbles on Clear okay and I'm seeing inside the coil, bubble clusters popping up. So I think that this is because if you notice too, it's kind of hard for you guys to see, but right in this area. right here, it seems like the coil coating is completely discolored and you get condensation dripping off the TXV and I think it's slowly worn out the coating on the coil. and I think it's leaking internally and it's actually like in the same spot. Look right in there. There's a bunch of bubble clusters. This one's kind of doing the same thing. You're getting bubble clusters right in here and you can see on this one better how the coating is just worn out in that one area right there. And I think that the leaks are coming from in there because I'm not seeing anything on the expansion valve. The expansion valve seems fine, the power head seems fine so, and we're clearly picking it up in the bottom of each coil. meaning the refrigerant's falling. so these coils are about five years old. You can see in the top they look good, but on the inside they're just leaking. So we're going to go ahead and quote new evaporator coils for this guy. two of them. Five Years On a waitress region, this is pretty much the lifespan of it. You're not going to get much more out of that because of the way that they store their Foods right? See all these different things up in the top are for salad dressings and they oftentimes keep them in the bottom and don't keep them covered so the stuff becomes Airborne See that blue stuff that's corrosion? Think about it like this: Statue of Liberty is made out of copper and it's green because the salt water is attacking it. Okay, that is copper and it's blue because the acids are attacking it and slowly causing leaks. The same thing is happening inside that coil. Even though there's a coil coating on it, it still only lasts so long. Now, if these weren't coated coils, they wouldn't even last five years. You'd probably get two years out of them if that. So, all right. Well, we'll get everything we need to know. We can see by this right here that these guys are from 2017. Now, um, we don't know if there's other leaks in the system, but we did our best. We know that we're getting them in both of these evaporators. We didn't pick any up really in the bar regions. I'll do a leak search on the roof before we finish, but this system took 10 pounds of refrigerant. It's a significant amount. it's just probably multiple leaks in both coils slowly leaking out is what I'm thinking when I get in here I can actually hear one of them I don't know if it's it's it's not really going to come across to you guys. but I can hear it bubbling and I sprayed soap bubbles all in the coil and you can hear it bubbling somewhere in the coil. But I just can't like I see little things but I don't see like I love to be able to just be like damn there it is, you know? But I'm seeing bubbles all inside the coil on both of them actually. but I can't hear it on the other one. but I'm picking up traces for sure. but I can hear it on this one and it's bubbling in there. So yeah, it's definitely in the coil if you look back here too. That copper line is all porous and pitted out too, so it's just worn out inside these things. So what I'm going to do is make a mental note I know they're going to approve this. So I'm going to take some measurements and make a mental note of how these things are prepped and set up because I'll prep these in the shop and get them all wired in and everything. and then boom. Just make connections right there outside the coil or right inside the coil and braise them in and be done and do all the prep work out the shop. So I'll measure all that and try to make it go easier. All right. So we're going to run the leak detector down in the condensing I'm gonna hit the hot spots. The low pressure control is a major hot spot. Oh look at that. Looks like our low pressure control is leaking too. So so we got a low pressure control issue. Yeah, okay, so we'll do that and then let's just look down here. It's going to be hard because that's going to be setting it off elsewhere. I'm not really seeing much else. I Think we'll add the low pressure control to the list of things that we're going to replace and then liquid line filter dryer. We'll probably put in a flare dryer packing's usually leak service valves. that's why you always put the caps on. They always have a little bit of leakage going on. That's because I loosened the packing. That one's leaking just a little bit. see it kind of rising right there. So all right. Well, we'll add a low pressure control on all the dryers to the mix too. All right. This was a basic walkthrough of how I approach systems like this. Now this is a multiplex system. Okay, we have one compressor and it runs one, two, three, two different boxes. No three different boxes that each have. Let's see, the waitress region has two evaporators and then each bar region has one evaporator right? And they each have their own stats and solenoids. Thermostat and solenoid will often call it a Statin solenoid. Okay, um, so on a multiplex system, you could have you know just the waitress reaching calling or you can have just one of the bar regions calling and everything else be shut off. With that being said, there's a lot of piping going downstairs. so that's why in the video I mentioned how important it is to understand that systems need to be designed for the type of condensing units you're going to be using, right? The manufacturer designs their condensed unit to to be able to hold so much liquid refrigerant, but they don't know how long you're going to make the line set and how many evaporators you're going to put on it. Okay, they oftentimes will have some sort of metric that says you know this system is designed for a hundred foot line set or something like that, but it's very important that we understand. Just because you know it says that it requires an extra four pounds for the flooded charge doesn't mean that once you put all the systems needed refrigerant under normal conditions in it, that it can handle that extra four pounds of refrigerant. So it's so important to verify and you know it's really important. This is one of my pet peeves when people do not put their high side gauges on systems. When they are pumping them down, you always have to put your high side gauge on there. That way you can be a hundred percent sure that your system is not overcharged and then go the extra mile even after pumping it down. I took the thermal imaging camera and I checked the liquid level too to make sure that I wasn't overfilled because it was a little bit cooler outside. It's really important. And then I marked the liquid level for the next guy. So the next guy theoretically shouldn't have to go through what I did in. um, well, I mean it's really not going to be that hard because the the pamphlets on there, but still, he shouldn't have to go through that. he can now just fill it up to that Mark on the the receiver and from that point forward. so I like to do that on a lot of my systems once. I've calculated the proper charge whether it be using Sporlins 90-30-1 method, whether it be leaning on the manufacturer I always like to Mark the liquid level. so that way the next guy doesn't have to go through all the steps that I did and he can just simply just add refrigerant until the liquid levels at that Mark and then he knows or she knows that The system has enough refrigerant in it, right? So it's so important to understand how the head pressure control valves work. And I want to say that there is so many incorrect methods of charging systems that have had pressure control valves. All right? I've heard some crazy claims of how you block off the condenser and clear the sight glass. Uh, you know, at certain pressures like no, that's not how it works. Okay, now there is one other method, right that I didn't mention in the video. If You Were Somehow To figure out what the coldest day of the year is and actually come out when it is the coldest day of the year and clear the sight glass on the coldest day of the year. Well, then you know that you have enough refrigerant in the system. Okay, but that's pretty impractical. Most of the time you're not going to know that it is the absolute coldest day of the year. It's just not going to happen that way. Okay, keep that in mind, but please understand, there's nothing to be afraid of when it comes to head pressure control valves. Okay, they're not. They're not even ex. They're nothing fancy about them. Okay here. I have a cutaway of an Lac valve. This is a Lac 180. This is the exact same valve that is in that system. Look, there's nothing to it. There's a power head that puts downward pressure right. This has a 180 PSI of pressure in it, pushing down on that and it has to overcome the system pressure. So the moment that the system's pressure drops below 180. PSI This thing starts to close the valve or it starts to uh, block off the flow coming out of the condenser and back up the refrigerant into the condenser. and then it feeds discharge gas directly into the receiver. There is nothing Difficult about the Lac valve. Now you get into the Oroa valves. They're a little bit more complicated, but they work off of the same principle. You get into the or, um, the Ori valves the the hold back valves. Same thing. Okay, there's nothing too fancy. I Will say that head pressure control valves are one of the most misdiagnosed things and a lot of people. They say all these things suck every time I See them. I Just cut the tip on it and put in a fan cycle control and call it a day. Fan cycle controls are not the best method Now, while they may work in most in some climates, they're really not the best method. Fan cycle controls are very violent on the system, especially if they have mole or a single condenser fan motor. If you only have one condenser fan motor on the system and you put a fan cycle switch on there, just put your gauges on that watch the the sight glass. When the fan cycle switch shuts off the condenser fan motor and then turns it back on. Watch how violent the sight glass empties, then clears, then empties, then goes flashing and it's just it's It's Mass Violent swings in the system and it's unnecessary. You put in a head pressure control valve if the system's designed for it right. it has enough storage and you'll notice that it's just really smooth right and you have consistent liquid temperatures. Now something to remember too. Just because my head pressure control valve is bypassing it 180 PSI doesn't mean that every other one is going to do that. Newer valves are dropping down as low as 100 PSI Okay, we're floating head pressure down. We're reducing the condensing temperature, because let's think about it if we reduce the condensing temperature. If we reduce the head pressure right? If we change the compression ratio of the compressor, we reduce the wattage right and we reduce the energy consumption of the compressor. So if you design your system properly, you can drop the head pressure and and reduce that so that way they can save energy. So that's a very common thing happening, especially on the new AF compliant units. That's a whole other topic for another day. but I Really, really appreciate you all. Uh, once I get an approval on this, we'll definitely try to film the install of the new evaporator coils and uh yeah, that's it. I Really appreciate you and we will catch you on the next one.