How To Refill R22 AC With Subcooling Method

hey guys jay here with word of advice tv i have an air conditioner unit right here that is slightly low on refrigerant it had a little leak at the schrader valve that's already fixed so all i have to do now is just add some r22 to it and i have a video where i show a improper way of how to add r22 i got quite a bit of flack for that but if you're interested to see that you can check that video out but in this video i want to show you the proper way of adding r22 using the wet bulb the dry bulb and super heat and sub cooling so i have my gauges already on i got the high side and the low side connected but in order for us to charge to find out what to charge by using the super heat or the sub cooling method i first need to find out what metering device is inside at the a-coil that will determine if i'm going to have to add using the sub cooling method or the super heat if i have a txv metering device i will be using the sub cooling and if i have a piston or fixed orifice i will be using the super heat so on this tag it says metering device txv indoor so supposedly it has a txv metering device but from my experience just because it says something on here doesn't mean that's what's inside so the best way is to visually verify what kind of metering device you have inside so let's go ahead and try to do that right away okay so we're inside and in this setup the the a-coil or the evaporator coil is sitting right in top of the furnace and the metering device is going to come in on the discharge line and it'll be right behind here so let's take this putty off and take a look inside unfortunately the hole is a little bit small i can't quite tell what kind of metering device we have basically all we're looking for is if it's a txv or not sometimes you'll get lucky and that metering device will actually be right in front of the a-coil all insulated and stuff in that case you don't need to look inside but in our case i can't really see it so we do have to peek inside somehow so let's put this putty back on and then i think what i'm going to do is just looks like there's a hole back here i'm just going to take this tape off that looks like an easy access point so one way or another either you take off screws bend it a little bit and peek inside or if you have a convenient little opening like this or maybe i'll just maybe i'll just puncture it ever since i started wearing a pocket knife in my pocket i've never regretted it so let's see okay there you go so i'm not sure why this hole is here but it is and that's actually pretty convenient for me to take a look over there and see what kind of metering device we have so i found a little mirror if you have an inspection camera then that makes things really convenient and unfortunately you're probably not going to be able to see what i'm looking at but basically i'm just looking at this wall right here to see what kind of metering device i have and i'll let you know what i find okay so what i see is a txv metering device which is right right behind here so that's what i thought it was but i just wanted to confirm and make sure so right behind we have the txv metering device which means we're going to be using the sub cooling method to figure out how much refrigerant we need to add so let's put this back and i'm gonna need to get a piece of tape and we'll just go ahead and tape this back up okay we have another layer of tape i guess we'll count that as extra insulation and while we're inside we may as well get our wet bulb as well i used to use a uei psychrometer now i use an amp probe and i've been really liking it this amp probe is it works very nice so it's a digital psychrometer and what we're after is the wet bulb so you do need to get the wet bulb reading from indoors you can take this reading pretty much anywhere in the house some techs will recommend getting this reading right by the return so you find the biggest return grill in the house and measure it there some guys say to just measure it in the mechanical room by the furnace or stick it into the return i just generally take this reading right by the furnace so right here we got wet bulb we could shake it around make sure it's getting a good reading let it stabilize so our wet bulb is probably going to stabilize at 69 degrees okay so we found out that it's a txv inside we found out our wet bulb i got my refrigerant right here we have our gauges hooked up i got my meter with a temp clamp i don't have an infrared gun right now so i'm going to use a regular old pipe clamp on here put that on our discharge because that's where we get our sub cooling reading i have a video on where to not where to i have a video on how to read super heat and sub cooling if you want more on that you can look at that video switch that to temp okay so everything's hooked up and ready actually i gotta hook up my tank and i wanna actually talk a little bit more about this because on the previous video the improper way a lot of people were asking about why were you adding in vapor aren't you supposed to add it in liquid what's a vaporizer etc etc so long story short if it's a blended refrigerant you can only add that as a liquid which means you will flip the tank upside down with r22 which is not a blended refrigerant you can add it as a vapor and that's actually preferred but the thing is as the refrigerant as you have less and less refrigerant in the tank as you're using it up there's not enough pressure inside the tank to push it inside the unit in that case you would flip it over and use the liquid now when you're adding refrigerant as a liquid regardless of what kind of refrigerant it is you want to throttle it in or use a vaporizer so the vaporizer is basically a little device that turns your liquid refrigerant you basically attach it to your fitting on your hoses and that little device turns your liquid refrigerant into vapor before it comes into the unit as you're adding it so that's a vaporizer or you can use the throttling method and what that is is as you're adding refrigerant you want to open your gauge just slightly so that the pressure goes up not more than 10 to 15 psi over the starting point so wherever the arrow is already at when you start adding refrigerant you don't want to open it full blast you want to just open it so it goes up by about 10 psi and then you just keep adding like that and making sure that that arrow does not go more than 10 psi from the starting point and if you're not sure what i'm talking about here check out my previous video where i opened it full blast as i was adding it as a vapor and you'll see the difference so in this video i'm going to be adding it as a liquid to show you an example of that i'll flip the tank over and i'll be throttling it in just opening up slightly and adding refrigerant until we get our required sub cooling reading now normally i would use the super cool slide rule chart to figure out how much refrigerant i need to add i've lost mine but that's okay um right on the name plate it says that it's kind of faded out you're probably not going to be able to see it but it says indoor txv sub cooling 13 degrees so that's our target sub cooling we want it to be about 13 degrees everything's ready in order to add refrigerant to the unit we do have to have the unit running though so i'm going to go ahead and turn the unit on and then we will proceed to add refrigerant until we get 13 degrees of sub cooling and by the way if your nameplate is completely faded out or for some reason it doesn't even have a rating what the txt sub cooling should be then the average for most units is somewhere between 10 to 12 degrees of sub cooling if you have a txv and also there's an app if you're going to me if you're going to add by superheat or sub cooling this app will work for both of them i prefer using the chart but if you're in a pinch or if you need something quick it's called super cool pretty sure this is the same people that make the super cool slide rule so here's the app this is what it looks like it has a bunch of charts that you can use troubleshooting guides and all that so you press chargey unit it asks you what it is is it non-txv or txv so let's just say it's txv you pick what refrigerant you're using let's say it's r22 and see right here it asks you what your target sub cooling is in our case it would be 13 degrees that's what we're looking for we go to next and this app makes it really fairly easy all you have to do is put in the numbers press calculate and it'll tell you what to do so let's look at our gauge here our high side pressure is at 150 psi so let's put that in there we go 150 and our liquid line temperature i already have my clamp on there is 81 degrees so let's set that to 81 and press calculate so right here it tells me add refrigerant so basically what this app wants you to do is add some refrigerant put in your new numbers press calculate again until it tells you that you're in the green but i'm not gonna use this app right now i'm just gonna keep mirroring my sub cooling until i have about 10 to 13 degrees just wanted to show you guys just in case somebody wants to try using this or if you know of an app that's even better than this one i would love to hear about it in the comments below so to measure sub cooling we're going to do the gauge saturation temperature minus the line temperature so we got about 80 degrees on our high side and 81 degrees for a line temperature so we pretty much barely have any sub cooling at all it's pretty much a zero so we're probably a little bit lower than i even thought or maybe the txv is just compensating for that so let's go ahead and add some refrigerant and i'm going to use the throttling method like i mentioned before so right now we're at 75 psi i'm gonna go up to about 85 psi when i open this up so i'm opening up really slightly if you open this thing up full blast and liquid you can slug the compressor you never want to do that so i can close this up again i'm still at 75 so i'll open it and go up to somewhere about 85 90 psi that's 10 to 15 degrees more than my starting point and that arrow is kind of bouncing up and down because that liquid refrigerant is getting sucked into the unit and that's how you throttle it in you just keep doing this you add a little bit you close it you wait a little bit for it to stabilize with a txv it takes a little bit of time for it to adjust and then you keep opening it and adding a little bit more a little bit more until you get close to your target sub cooling or target superheat if you don't have a txv metering device so right now our saturation temperature is 90 degrees and our meter is 76. so we actually have 14 degrees of sub cooling right now so i'm gonna stop adding and just wait for it to stabilize okay so it's been a couple of minutes this went down to about 89 degrees and this is pretty steady at 76. so that's right about at that 13 degree sub cooling that we were looking for so that is perfect this unit is charged like it should be the suction line is sweating profusely which is also a good sign and i think i'll just go inside and also take the temp drop our delta t and make sure we have a good temp drop as well and then we'll call it good well guys and that is how to properly charge or recharge an air conditioner unit i hope you found this video useful thank you so much for watching don't forget to mash that like button on the way out and we'll see you next time [Music] you

Channel: Word of Advice TV

Views: 319,237

Keywords: how to refill ac, how to refill air conditioner, how to refill home ac, how to refill home air conditioner, how to refill air conditioner gas, how to refill ac r22, how to refill air conditioner by r22, how to recharge ac, how to recharge air conditioner, how to recharge home air conditioner, how to charge ac using subcooling, how to charge home ac, how to charge air conditioner, how to recharge ac system, how to add freon to ac unit, word of advice tv, refrigerant, freon

Id: GlS8aAkUBT4

Length: 14min 36sec (876 seconds)

Published: Sat Sep 12 2020