Adding R410A Refrigerant To AC (subcool method w/TXV)

today we swapped out a new evaporator coil sitting on top of a furnace and we have a new condensing unit outside and we're about to start the system up and balance the charge in it which is what today's video is about now one of the things you need to know when you're bouncing a charge is whether or not you have a TXV on the system itself basically what a TXV does is it regulates the liquid refrigerant coming in on this smaller line here this is your high pressure side refrigerant comes in as a liquid into the evaporator coil it turns into a vapor the heat from the home goes through the evaporator and the vapor refrigerant absorbs that heat comes back out goes back out to the condensing unit but you see a bulb here this Bulb Has refrigerant in it all by itself and there's a little tube that goes down into a coil and back into the thermal expansion valve so basically as this works is the as the refrigerant absorbs heat from inside the house it will expand the refrigerant inside this bulb because it heats up and that expansion creates pressure that opens using closes this valve so it regulates the refrigerant because of that we have to charge off of our temperature and pressure settings off of our liquid line which is our sub cooling outside I'm going to go ahead and insulate all this and then we'll get started before we go outside just wanted to show you guys that I have a temperature probe here located in the ductwork above the coil and I have another one down here below by the return so basically what I'm doing is I'm getting two temperature readings I'm getting the temperature readings of the air coming in from the house going into the unit as it goes through the unit cools down and then getting another temperature of the air exiting and this is going to give me a temperature difference of the air on both sides of this coil and that's part of our charging process we have the system on the vacuum the service ports are still closed so what we're going to do is I'm going to have one go ahead and open up the service ports you're going to start on the suction side there she's going to open that first and these units they come pre-charged with refrigerant but because of the different lengths of line sets we have to balance these charges because they're not always spot on so he's going to open up that suction side first and he's going to open up the liquid side all right so now our server ports are wide open we're putting our disconnect into the on position I got the breakers in the panel inside the house back in the opposition and the thermostat is already calling for cooling one so all I need to do is flip on the burner switch on the furnace and as soon as that switch comes on this unit should start right up so what I'm going to do is I'm going to give it about 10 minutes or so just to run and equalize we have a TXV on this system so we have to go by our subcooling which is going to be on this small liquid line here so I'm going to hook up a temperature probe to that line when you're looking at the gauges here you see on the suction side there is a pressure and a temperature correlation so we're running 410 that's the pink area here so you want it to be above 32 degrees Fahrenheit anything below that will freeze water so when you have when you have hot air going over a cold coil inside and the temperature of the refrigerant is less than 32 degrees it's going to start freezing that condensation that builds up on the coil we want that temperature to be up higher over 32. we want to charge off the high side sub cooling so our pressure gauge here is reading just a hair over 200 we have about 70 degrees on there now I want to compare that temperature to the temperature of the probe that I'm reading over here and what we're looking for is a ballpark of 10 degrees sub cooling now you can see here what I'm reading on the app is uh just under 72 degrees and that's on this probe here and I'm reading about the same here I'm reading about 72 degrees on the gauge so what I want to do is I want to add refrigerant and fill this temperature on the probe and this temperature on the gauge are reading about a 10 degree difference now there are charts and temperatures charts and all that stuff that you can kind of go through to get exactly what your sub cooling reading should be when you're charging 410 into a system you have to add it as a liquid because 410 is actually a blend of two different refrigerants and if you let it vaporize those two refrigerants are going to start separating and you're not going to get the proper blend in the unit so we have our bottle open here we have our hose hooked up to our manifold You Follow the yellow hose and this is where we're going to add our refrigerant and once we got that all open you want to go ahead and you want to bleed some of the air out of the line because you don't want to put air into the system we just performed a whole vacuum to get all that air out so I'm just going to crack this blow some of that refrigerant out and then we're going to go ahead and flip this bottle upside down so what you're doing when you flip the bottle upside down is whatever Vapor that's in this bottle is actually going to be towards the top here and we're adding refrigerant from the bottom so we know it's going to be going in as a liquid so now we're ready to add refrigerant so what I'm going to do is I'm going to open up my suction side here this is the this blue hose here is hooking up to the suction side which is the larger line on my refrigerant because that is a lower pressure so when I open up the manifold to let refrigerant in it's going to suck in on this line when you add liquid refrigerant into a system on the suction side you got to be very slow and methodical about it because this suction line is going straight into the compressor and compressors do not compress liquids so you want to add it just a little bit at a time so that it vaporizes in that drop in pressure before it hits the compressor so that you're not slugging the compressor as they say so I'm going to crack it open you'll see pressure Rises as I'm adding refrigerant and as I close it off it drops back down and you're going to slowly see this Needle start to rise so I'm just going to keep doing that until I have a temperature difference of 10 degrees between this and my probe you're going to see these temperatures and pressures kind of bounce around when you do that so you'll want to wait a couple minutes for it to stabilize again before you add any more all right so that's holding at around 73. and what I got over here 73.74 so I still got plenty to go foreign another part of this you want to check your temperature difference inside that's your delta T So as you can see here I've got 15.7 15.8 so your ballpark when you're when you're at that right charge when you're about 10 degrees subcoin you should see it between 18 and 23 degrees Fahrenheit on that temperature difference between the two probes on the air inside so right now I'm at 15.8 and my sub cooling is about three or four so we're just going to keep going all right so right now I'm reading about 78 degrees on my gauge I'm reading about 73 degrees on my my probe over here so I have about five degrees sub growing so I'm about halfway there I'm going to keep going you see the pressure now is up to about 80. look at my temperature down here my probe about 71 and it's dropping so if that thing settles in right around 70 I'm right there at that 10 degrees so I'll let this run for a couple minutes see where it settles out all right so I got about 10 and a half degrees or so sub cooling uh between my temperature on my gauge and the temperature on my Probe on the liquid line I got about 19 degrees delta T that's the temperature difference inside between both sides of the evaporator coil there and I'm ready to disconnect my hoses and call it a day so what I'm going to do first is I'm going to leave this suction Side open all right I'm going to close all the other valves make sure they're closed I'm going to go ahead and flip this tank back over I'm going to close it up so what I'm going to do now is I'm going to suck all the refrigerant out of my hoses and out of my manifold so I'm going to do that by using this suction on the unit itself so I'm going to close off my high side all right because I want to suck all the refrigerant that's still in this hose and I'm going to leave the low side open so by doing this everything that's in my manifold is going to get sucked through that hose into the line so that's closed that's open and now I'm going to leave my suction on my manifold open I'm going to open up the hose where I was adding the refrigerant I'm going to pull all the refrigerant that's in that hose and I'm also going to open up my high side all right and you can see how the pressure really drops down that's the unit itself sucking all the refrigerant out of my hoses so once that drops down all the way it's going to equalize with the pressure I'm going to go ahead I'm going to close my manifold handles back up all of them I still got this valve closed I'm going to go ahead and close my other valve and I'm just going to go ahead and disconnect and that's it we're done

Channel: Jersey Mike HVAC

Views: 8,248

Keywords: charging ac system with gauges, charging split ac sytem, r410a refrigerant charging, hvac training videos, adding refrigerant to air conditioner, adding refrigerant to ac unit, adding refrigerant, r410a, R-410A, r410a charging, r410a refrigerant pressure, hvac, refrigerant, how to add refrigerant to home ac, 410a charging, ac system recharge, How to add refrigerant to air conditioner, charging split ac system, refrigerant charging procedure, how to recharge home ac system

Id: VG7ygGg6xvg

Length: 10min 10sec (610 seconds)

Published: Fri Jun 09 2023