These charts are very helpful. Most new units today actually have them included. Most of his videos are about Central air and basic principles of refrigeration. Not mentioned is if your condenser has a accumulator tank. You will find these on almost all commercial units. They serve for two purposes. One if you want to pump down the system, close the liquid line valve & forces the compressor on. It will store refrigerant in this tank to do evaporator repairs. The other thing is you don't have to be spot on with charging the system. This accumulator will serve as a temporary holding vessel as out door or indoor temperature changes. Only expansion valve evaporators use a accumulator tanks. If your working with orifice tubes on a freezer,kegartator, or glass window display box, anything that does not have a expansion valve, This accumulator will not exists. The high side/liquid line will go from the condenser straight to the orifice tubes. I always install a dryer/filter right at that point to prevent blockage of the tubes. If you ever suspect blocked orifice tubes, "suction low and high head pressure with poor cooling", connect your nitrogen tank up and give those lines about 350 psi. They will clear right up. This guy knows his stuff and demonstrates well in his videos.
I think you are getting the accumulator and receiver confused. The receiver is located on the high side of the system and will serve two purposes. It guarantees that no vapor will enter the metering device and with the use of a king valve be closed off to hold the charge for repairs on the low side of the system. The accumulator is located on the low side of the system and ensures that no liquid enters the compressor.
Awesome! Hey I had some coffee before watching and had to speed you up to play back speed of 1.75 HaHa! Great video...I follow your others and have learned more quicker from you than my Tech School. Will tell me friends at school about you!
Sir. Maybe you can answer this. I've seen videos demonstrating pumping down refrigerant back to compressor. Why does the compressor continue pumping when the pressure builds on the high side pumping into a closed valve and the pressure drops to vacuum on low side? I would expect pressure sensors would cause the compressor to cut off well before all refrigerant has pumped back to outside unit.
And a 2nd question from me. When connecting gauge houses on to a port why wouldn't a small amount of air mix with the refrigerant vapour on low side? Even though the pressure should be pushing out of the port I'd expect there to be some kind of mixing at the air and refrigerant junction where they meet at the port and hose connector especially if hoses left on for a long time.
+yoyofd That would mean it's out of range. If you ever fall in the "X" recover what ever is in the unit and start over weighing in the refrigerant charge.
+yoyofd The parameters I have used are for a correctly operating system at design conditions. High or low pressures can caused by many different problems. Dirty coils, evaporator or condenser and improper charge are a couple of common issues.
Sir, I used to be able to find your chart on Google and had it saved onto my phone but had lost it. Is there a link you can send me to download your chart? I really like this chart vs others.
Cool Cat HVAC/R Training Video Thank you for the quick response. No worries, guess I'll just have to find another to use. Great explanation about the topic.
Well after watching all vids I could I felt confident enough to top off my 2 ton package unit with R22 using the superheat method. All is well now with one anomaly maybe someone can answer for me. The SLT goes from 66 to 48 to 66 again over and over. It has a fixed orifice with cap tubes to the evap. It took 2.8 lbs but blowing cold but I haven't seen a vid yet about this ping pong SLT. Anyone? Thanks.
This could be a little tricky to diagnose with out more testing. I'm curious as to what the sub cooling temperature is. If the refrigerant from the condenser has not completely changed over to a liquid and there are pockets of vapor entering the metering device that could cause wide swings in the low side pressure and temperature readings. Also the superheat reading is important to determine if the evaporator is starved.
Target SH for that day was 15 deg F. With a SLT of 63 I was good and stopped R22. Then after running for a while this swing in SLT started. Unit is only 4 yo. Good thing there is the exact same unit on the roof (duplex) put in at the same time. Put the gauges on it. Head press is 235 while the unit I'm trying to service is at 215 psi. Units were put in the same day, Payne, identical. So by comparison, should I simply add more R22 to the unit under repair to bring the head pressure up to 235? Thanks.
What you are describing is what is called "hunting". It is most often found on units that have TXV metering devices and caused by intermittent loss of subcooling (vapor enters the metering device). I think the unit is under charged. It is apparently happening on a fixed orifice system. The capillary tubes you were describing are likely circuit tubes coming from the distributor, a fixed orifice piston style metering device is located in the distributor body. The distributor prevents pressure drop in the evaporator.
Yes definitely has cap tubes maybe 6 or so going from the piston to the evap. The tag on the inside says 5.9 lbs R22, came precharged and I've added 2.8 lbs. I have a sniffer and all I can find is the schraders leaking a bit so I put brass caps on them , all good there. The head pressure on the other unit kinda give me a clue I should maybe add just a pinch more. Thank You for taking the time to help me out. B/R. Vince
@@coolcathvacrtrainingvideo9906 Keith, are you kidding me?? Don't even acknowledge this ungrateful prick. Your knowledge/mind runs orbits around this punk!
"for one thing...they didn't call you out there because it was nice and cool inside" haha thanks for the video very good teacher.
Thank you very much for sharing your knowledge. It make our lives easier. Wish more people had your attitude Mike
Great training video for my guys. You handled the material in a logical concise manner. Thank You
Thanks, I appreciate the compliment.
These charts are very helpful. Most new units today actually have them included. Most of his videos are about Central air and basic principles of refrigeration. Not mentioned is if your condenser has a accumulator tank. You will find these on almost all commercial units. They serve for two purposes. One if you want to pump down the system, close the liquid line valve & forces the compressor on. It will store refrigerant in this tank to do evaporator repairs. The other thing is you don't have to be spot on with charging the system. This accumulator will serve as a temporary holding vessel as out door or indoor temperature changes. Only expansion valve evaporators use a accumulator tanks. If your working with orifice tubes on a freezer,kegartator, or glass window display box, anything that does not have a expansion valve, This accumulator will not exists. The high side/liquid line will go from the condenser straight to the orifice tubes. I always install a dryer/filter right at that point to prevent blockage of the tubes. If you ever suspect blocked orifice tubes, "suction low and high head pressure with poor cooling", connect your nitrogen tank up and give those lines about 350 psi. They will clear right up. This guy knows his stuff and demonstrates well in his videos.
I think you are getting the accumulator and receiver confused. The receiver is located on the high side of the system and will serve two purposes. It guarantees that no vapor will enter the metering device and with the use of a king valve be closed off to hold the charge for repairs on the low side of the system. The accumulator is located on the low side of the system and ensures that no liquid enters the compressor.
Perfectly explained. Thank You.
Thank you very match for your Explanation
I'm an auto mechanic and I've never seen anyone explain refrigerant temperature relationships like this
🙏
Awesome! Hey I had some coffee before watching and had to speed you up to play back speed of 1.75 HaHa! Great video...I follow your others and have learned more quicker from you than my Tech School. Will tell me friends at school about you!
Nice video and awesome explanation. T.Y.
Thanks so much great video
Sir. Maybe you can answer this. I've seen videos demonstrating pumping down refrigerant back to compressor. Why does the compressor continue pumping when the pressure builds on the high side pumping into a closed valve and the pressure drops to vacuum on low side? I would expect pressure sensors would cause the compressor to cut off well before all refrigerant has pumped back to outside unit.
And a 2nd question from me. When connecting gauge houses on to a port why wouldn't a small amount of air mix with the refrigerant vapour on low side? Even though the pressure should be pushing out of the port I'd expect there to be some kind of mixing at the air and refrigerant junction where they meet at the port and hose connector especially if hoses left on for a long time.
Finaly thanks , great video, but wonderin g what the x stand for
+yoyofd That would mean it's out of range. If you ever fall in the "X" recover what ever is in the unit and start over weighing in the refrigerant charge.
Hi i have a cuestion . What if the psig are to hi or low does it mater , is there a max or min on psig? Hope you have the time to answer thanks!!
+yoyofd The parameters I have used are for a correctly operating system at design conditions. High or low pressures can caused by many different problems. Dirty coils, evaporator or condenser and improper charge are a couple of common issues.
awesome, awesome video!!!!
Thank you
Sir, I used to be able to find your chart on Google and had it saved onto my phone but had lost it. Is there a link you can send me to download your chart? I really like this chart vs others.
I just looked, I couldn't find it either.
Cool Cat HVAC/R Training Video Thank you for the quick response. No worries, guess I'll just have to find another to use. Great explanation about the topic.
Lazy I was able to find that chart artikool.tripod.com/sitebuildercontent/sitebuilderfiles/propersystemcharging1.pdf
awesome thank you
can i know the website written on the bottom of the paper?
Just google Pressure/Temperature chart and several different ones will pop up.
Well after watching all vids I could I felt confident enough to top off my 2 ton package unit with R22 using the superheat method. All is well now with one anomaly maybe someone can answer for me. The SLT goes from 66 to 48 to 66 again over and over. It has a fixed orifice with cap tubes to the evap. It took 2.8 lbs but blowing cold but I haven't seen a vid yet about this ping pong SLT. Anyone? Thanks.
This could be a little tricky to diagnose with out more testing. I'm curious as to what the sub cooling temperature is. If the refrigerant from the condenser has not completely changed over to a liquid and there are pockets of vapor entering the metering device that could cause wide swings in the low side pressure and temperature readings. Also the superheat reading is important to determine if the evaporator is starved.
Target SH for that day was 15 deg F. With a SLT of 63 I was good and stopped R22. Then after running for a while this swing in SLT started. Unit is only 4 yo. Good thing there is the exact same unit on the roof (duplex) put in at the same time. Put the gauges on it. Head press is 235 while the unit I'm trying to service is at 215 psi. Units were put in the same day, Payne, identical. So by comparison, should I simply add more R22 to the unit under repair to bring the head pressure up to 235? Thanks.
What you are describing is what is called "hunting". It is most often found on units that have TXV metering devices and caused by intermittent loss of subcooling (vapor enters the metering device). I think the unit is under charged. It is apparently happening on a fixed orifice system. The capillary tubes you were describing are likely circuit tubes coming from the distributor, a fixed orifice piston style metering device is located in the distributor body. The distributor prevents pressure drop in the evaporator.
Yes definitely has cap tubes maybe 6 or so going from the piston to the evap. The tag on the inside says 5.9 lbs R22, came precharged and I've added 2.8 lbs. I have a sniffer and all I can find is the schraders leaking a bit so I put brass caps on them , all good there. The head pressure on the other unit kinda give me a clue I should maybe add just a pinch more. Thank You for taking the time to help me out. B/R. Vince
He said "I hope this has been abuse to you, goodbye". That's not nice.
:)
He said "I hope this has been a USE to you" not abuse.
Due to my southern accent I have been called the "Hank Hill" of refrigeration. LOL!!!
@@coolcathvacrtrainingvideo9906 your voice so unique in youtube hvac. I appreciate you dedication to this tutorials.
Take the tobacco out of your mouth
LOL, no tobacco, it's a by product of being born and raised in the south.
@@coolcathvacrtrainingvideo9906 Keith, are you kidding me?? Don't even acknowledge this ungrateful prick. Your knowledge/mind runs orbits around this punk!