How to Read SUPERHEAT and SUBCOOLING

hey guys jay here with word of advice tv in this video i want to show you how to measure superheat and sub cooling and that's it just how to measure it i'm not going to go into how to troubleshoot it how to diagnose it what super heat and sub cooling is the science behind it any of that i'm simply going to show you how to measure it because i know when i started out as a tech i mean when i started there wasn't as much stuff online not as much info that you could look up nowadays there's a ton of stuff you can look up on google and youtube but when i just started out i forgot often times which one how to measure super hit and sub cooling which one is the measurement for super heat and which one is the measurement for sub cooling so i'm going to show you that real quick explain how to measure it and i'll also show you what i wrote on my gauges in the past just as a reminder to myself so the first thing you want to do is of course hook your gauges up the low side and the high side the low side is the suction line which is this blue hose blue gauge the high side is the red which is the red hose and the red gauge this is the discharge side and i like to make sure that all my fittings are on there securely that way when i put my hoses on refrigerant is not spewing out if they're loose so now they're all secure we know that i'll just hang this over here okay so our suction line or the blue hose is always going to be the thicker copper line so that's the one that's sucking refrigerant in and our discharge is the one that's pushing refrigerant out so i'll take the access caps off sometimes the o-ring stays on there pay attention to that take the o-ring off slide it back into the cap if it doesn't go back in there neatly and flush you might need to take a little screwdriver and just push it in there and this one is missing an o-ring as well if there's no o-rings the refrigerant could leak by a little bit if the schrader valve is leaking so optimally you do want to have o-rings inside of the caps i'm going to replace these after i'm done with brass caps that have the o-rings in them and of course when you're dealing with refrigerant it's always a good idea to wear some gloves so if some of it is spreading out it's not going to frost bite your hands i also have low loss fittings on my gauge set and that helps a lot with refrigerant not escaping these thicker fittings right here the hoses are a little bit more expensive but i think it's well worth it so let's put on our low side and our high side i like to put my gauges on when the unit is off but in order to measure the superheat and sub cooling we will need to have it running so let's put the hoses on [Music] look at that not even a spurt that's why i love these low loss fittings so that's the low side here's our high side just like that okay so now i have both sides connected and if the unit has been off for a while the pressures should be equalized and they are so this is about 125 psi on the low side and it's about 125 psi on the high side which is good when the unit is off the pressures do need to be equalized and one last thing you will need to take these measurements is a pipe clamp to measure the temperature or if you have an infrared gun that you could just aim at the pipe and shoot it that way that's even easier i left mine accidentally at somebody's house as a souvenir so i'm back to using my pipe clamp which works pretty well too so i'll clamp this on my suction side to begin with leave it there and then i'll put my temperature probe in my meter okay so we're ready to get our reads and before we get into that let me just explain what i'm going to be looking at when we turn this unit on so i'll put my gauge here for now so if we take a look at my gauge my gauges this is a r22 unit so we're going to be looking at the green scale right here that's the r22 scale we're not really going to be looking at the psi so you do have to have a manifold gauge that has the refrigerant that your unit has so in our case the r22 the saturation temperature is this green scale right here so to get our super heat reading we're always going to use the low side or the suction side so super heat is always going to be on the low side whereas the sub cooling you're always going to get that reading from the high side or from the red gauge and we're going to be using the green scale on here as well so basically to get the measurement of the super heat and sub cooling you're going to be doing the line set temperature minus the gauge temperature or you're going to be doing the gauge temperature minus the line set temperature and back in the day when i couldn't remember what's what i used to write behind my gauges as a reminder to myself i would write g minus l equals s c which stands for gauge temperature so the temperature on the gauge minus the line temperature so gauge minus line will equal my sub cooling reading and for the super heat it would be l minus g equals sh and that was like my little cheat sheet so on this one it's line temperature minus gage temperature equals super heat so that's an easy way to remember it or if you struggle remembering it you could just write it down like that okay so now we're all set i'm going to turn the unit on get the line temperatures for the suction and the discharge and from that we'll be able to use these little formulas to get our superheat and sub cooling readings and one last thing i want to do actually before i turn the unit on is purge the hoses so whenever i put these hoses on these hoses have a little bit of air in them and air is bad for the refrigeration system so i just like to crack my hoses open just slightly to purge any of the air or any air bubbles inside of the hose out so that one has been purged and on the high side just like that because when the unit turns on the suction side is actually going to suck this refrigerant back into the system so if there's air bubbles in here it's going to suck all that air back into the system and that's not a good thing that's why you want to purge them but anyway let's get back to turning this unit on and getting our super heat and sub cooling readings okay so the unit turned on and as you can see the low side went down because this is the suction side hence it's called the low side the pressure goes down on that and the high side the pressure goes up so it went from 125 to about 150 psi and this one dropped down to almost 75 psi so you want to have the unit run for a couple of minutes to let this temperature stabilize okay so the unit has been running for about five to ten minutes now the pressures have stabilized so now let's get our super heat reading which is going to be l minus g so that's going to be this is kind of fluctuating back and forth and that's because of the metering device but it goes up to about 48 degrees so if we take that 48 which is going to give us our line temperature minus the gauge temperature which in our case on the green scale is going to be about 40 degrees that gives us 8 degrees of superheat so our line temperature minus the gauge gives us our super heat which is 8 degrees of superheat and now i'm going to go ahead and move my clamp over on the high side and the clamp you want to put just a couple inches away from the service valve and that's a good spot to measure both the super heat and the sub cooling okay so now we got to just give it a little bit of time for the temperature to stabilize on my meter and the formula for the sub cooling reading is going to be gauge temperature minus line temperature so our gauge temperature is going to be about about 82 degrees on the r22 scale the green one so 82 degrees minus 72 gives us 10 degrees of sub cooling and that is good so our readings turned out to be 8 degrees of superheat and 10 degrees of sub cooling and that is how you measure superheat and sub cooling i hope that made sense if you have any other questions please let me know in the comments below or if you have any suggestions if you're a technician or some further tips we would love to hear from you as well anyway thank you so much for watching this video i hope it helped you out don't forget to mash that like button on the way out and i'll see you next time and if you're still here this is how to do a backflip as you're jumping you want to be already up in the air and then curl up and do the flip one common mistake is that people start flipping right away right when they jump and they don't curl up and they end up landing on their neck so this is how you do it and if you have glasses you probably want to take those off let's try it again there you go i haven't done this in a long time so it took me a few tries to regain it but that's how you do it let's try a front flip this time i'm getting old try this again [Music] you

Channel: Word of Advice TV

Views: 563,292

Keywords: how to read superheat and subcooling, how to read superheat, how to read subcooling, how to check subcooling, how to check superheat, how to check superheat and subcooling, superheat and subcooling formula, superheat and subcooling chart, superheat and subcooling explained, how to measure superheat and subcooling, how to measure superheat, how to measure subcooling, how to measure subcooling 410a, how to measure subcooling r22, superheat and subcooling, word of advice tv

Id: pUYLmxOrfo0

Length: 11min 42sec (702 seconds)

Published: Sat Sep 05 2020