You got confusing at 6:50 to 8 min. Weight on the scale was 15 oz(6 min). next time it was showed it was 3 oz (6:18 min) oz. Then you decided on 22 degrees of sub cooling due to a temp. change(7:02 min). Where was the change?
Technically it can be within plus or minus 3 of target superheat, so even if you were 3 over TSH. it should still be fine and not damage the unit right?
hi, my r22 suction saturated temp. is below 32F (around 20F). i tried to add some refrigerant to bring it up past 32F, but it won't go up. The low side pressure remains the same BUT the high side pressure rises. Do you think my filter drier is blocked? i see frost on the output of drier but not on the input side. i tapped at the drier and the low pressure drops to 0 on the low side. the unit has a piston . thanks.
A frost line does indicate a blockage. The reason the head is rising is the refrigerant is collecting in the condenser as a liquid and reducing capacity and rising head. GFM
Gman how do you clean your gauges to used on different refrigerant without contaminating the line? Interested on buying a set but I want used it for multiple refrigerant if possible.
Then contamination of the gauges set is generally not an issue. Bleeding out the set is all that is necessary. Possible exceptions are oil filled lines from oil charging or highly contaminated refrigerants. In any case, purging with nitrogen will eliminate the issue. GFM
hi, how do you find INDOOR superheat if there's no shrader port at the evap outlet? I see alot of A-coils that doesn't have a shrader port that you can hook your gauge up. thanks.
Question, my evaporator is dripping water into my furnace. The level is good, filter is clean, just clean the condenser last week and it’s still dripping water. House is cooling well. Any suggestions?
@@ericzou7753 I am assuming you meant the evaporator, not the condenser. I would be checking the temp diff across the coil. In a unit that is over 20 years old, you should have 18 to 22 F difference. New units may be about 18. Higher numbers indicate low air flow and a higher amount of moisture being taken out of the air. Higher air flow may help. Hope this helps. GFM
estrelladelnorte1308 Target superheat is generally taken at the inlet to the condensing unit to eliminate the heat gain from the line set. This is different than with a TXV. The superheat is set by the TXV and is measured at the outlet of the evaporator. GFM
I just bought one of these manifold gauges, it's very nice but I'm not real sure how to get the wet/dry bulb temps. I also have a dual temp gauge so I have the bare leads. My question is, how to get both readings in the real world (not on a test unit) and what's the 'little sock' and where do I get or make one? I can see you put the indoor wet bulb lead in the return air but how do you get the outdoor reading, ahead of time? I'm going to guess once you have the readings locked in, you go back to the clamps that connect to the high and low side lines. Great video as usual! I'm going back through your playlists and learning a ton of new stuff, thank you. I'm just freshly out of school and buying tools at this point, very expensive.
Jeff S The sock should have come with the gauge set. The outdoor temp is usually taken with a separate thermometer. Its one of the problems with the gauge set. GFM
GMAN, you make the best videos, Thank You. Quick question: What specific formula do you use to calculate your target super heat? Other professionals have suggested a formula; 3 multiplied by return air wet bulb minus a constant number (80) minus the outdoor temperature measured at the condensing unit. Does this formula sound reasonable to you?
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.
Place a screwdriver tip on the fixed orifice and place your ear on the handle while the unit is running. If the noise is a hissing sound, there is no air in the system. If the hissing is not continuous, but is broken up by bubbling noises, there is air in the system. Air will cause the variation in suction line temp. Hope this helps. GFM
Just went up to check it again. I put the screwdriver there. Lot's of noise but I can't really say if it was hissing or bubbling. But something weird happened. My SLT was at 63 just perfect and it wasn't moving. So I thought maybe it was me and I didn't give the gas enough time to circulate. 15 mins go by still perfect and I'm getting ready to put the cover back on and right then the SLT just started dropping all the way to 44. I just shut it down. Unit is 4 yo low on gas so I charged it up by superheat watching the videos. I bled my hoses. Oh well, thank you for your advice and I'll take a bit to think about my next move.
Am a little lost on this one. A good exercise for us newbies would be making diagrams on what's connected where, which end is receiving and supplying pressure, and such.
johnny danger I am interested in why you would like "pounds". The reason I use "psig" is to designate the pressure to be zeroed at atmospheric pressure. GFM
In the trade for 25 yrs up here in Canada. Love watching and brushing up with your videos. Thanks and keep them coming. I can always learn something.
Colin G Thanks for the support.
GFM
Is it celcius or far
Great video! The tip to remove refrigerant from the high pressure side when near SH target is awesome. Thank you
Welcome
GFM
Your a great teacher Mr. Grayfurnaceman. Thanks for sharing
Another good one GFM !! Take care, Brett
You got confusing at 6:50 to 8 min. Weight on the scale was 15 oz(6 min). next time it was showed it was 3 oz (6:18 min) oz. Then you decided on 22 degrees of sub cooling due to a temp. change(7:02 min). Where was the change?
I love the basics Nice video! makes me want to take the gauges away from my tech's and do it myself again!!
Good video I just had the exact situation last week!
Technically it can be within plus or minus 3 of target superheat, so even if you were 3 over TSH. it should still be fine and not damage the unit right?
I believe you are correct.
GFM
hi, my r22 suction saturated temp. is below 32F (around 20F). i tried to add some refrigerant to bring it up past 32F, but it won't go up. The low side pressure remains the same BUT the high side pressure rises. Do you think my filter drier is blocked? i see frost on the output of drier but not on the input side. i tapped at the drier and the low pressure drops to 0 on the low side. the unit has a piston . thanks.
A frost line does indicate a blockage. The reason the head is rising is the refrigerant is collecting in the condenser as a liquid and reducing capacity and rising head.
GFM
Gman how do you clean your gauges to used on different refrigerant without contaminating the line? Interested on buying a set but I want used it for multiple refrigerant if possible.
Then contamination of the gauges set is generally not an issue. Bleeding out the set is all that is necessary. Possible exceptions are oil filled lines from oil charging or highly contaminated refrigerants. In any case, purging with nitrogen will eliminate the issue.
GFM
hi, how do you find INDOOR superheat if there's no shrader port at the evap outlet? I see alot of A-coils that doesn't have a shrader port that you can hook your gauge up. thanks.
You use the tap at the outdoor unit.
GFM
Question, my evaporator is dripping water into my furnace. The level is good, filter is clean, just clean the condenser last week and it’s still dripping water. House is cooling well. Any suggestions?
The pan is good, it’s dripping from middle section of the evaporator coil, droplet just sits in the middle and drip down.
@@ericzou7753 Upflow or down flow?
GFM
grayfurnaceman its an up flow system
@@ericzou7753 I am assuming you meant the evaporator, not the condenser.
I would be checking the temp diff across the coil. In a unit that is over 20 years old, you should have 18 to 22 F difference. New units may be about 18. Higher numbers indicate low air flow and a higher amount of moisture being taken out of the air. Higher air flow may help. Hope this helps.
GFM
you have to be a few inches from the "evaporator" to check for superheat right?
estrelladelnorte1308 Target superheat is generally taken at the inlet to the condensing unit to eliminate the heat gain from the line set. This is different than with a TXV. The superheat is set by the TXV and is measured at the outlet of the evaporator.
GFM
I know when you use gauges it is deferent refrigerant on each gauges but can I use any refrigerant with digita gauges
As a general rule, you can interchange refrigerants with the gauge set. Some gauge sets will not read high enough for some refrigerants.
GFM
I just bought one of these manifold gauges, it's very nice but I'm not real sure how to get the wet/dry bulb temps. I also have a dual temp gauge so I have the bare leads. My question is, how to get both readings in the real world (not on a test unit) and what's the 'little sock' and where do I get or make one? I can see you put the indoor wet bulb lead in the return air but how do you get the outdoor reading, ahead of time? I'm going to guess once you have the readings locked in, you go back to the clamps that connect to the high and low side lines.
Great video as usual! I'm going back through your playlists and learning a ton of new stuff, thank you. I'm just freshly out of school and buying tools at this point, very expensive.
Jeff S The sock should have come with the gauge set. The outdoor temp is usually taken with a separate thermometer. Its one of the problems with the gauge set. GFM
What do you do if the labels or worn off or missing. My friend needs her system checked out and I don't know where to start!!!
You can get the target superheat chart off the internet.
GFM
Greetings Sir,
Should we take system super heat or evaporator super heat as base for charging a fixed orifice system? Pls di tell.
The super heat is measured at the compressor when charging with target superheat.
GFM
Thank you ! Nice video
what is the problem when the super-heat is jumping all over the place and will not hold steady
+Ken S There could be a number of problems here. Contaminants in the system, airflow problems, incorrect coil for the unit are common ones.
GFM
Was this video on a heat pump unit? I am assuming this since you are indoors.
This one is a heat pump.
GFM
GMAN, you make the best videos, Thank You. Quick question: What specific formula do you use to calculate your target super heat? Other professionals have suggested a formula; 3 multiplied by return air wet bulb minus a constant number (80) minus the outdoor temperature measured at the condensing unit. Does this formula sound reasonable to you?
+melvin292 I don't remember the formula. Usually I use the digital gauge set calculation. There are also charts.
GFM
Thnx for the reply sir
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.
Place a screwdriver tip on the fixed orifice and place your ear on the handle while the unit is running. If the noise is a hissing sound, there is no air in the system. If the hissing is not continuous, but is broken up by bubbling noises, there is air in the system. Air will cause the variation in suction line temp. Hope this helps.
GFM
Will do, I'll report back. Thank You!
Just went up to check it again. I put the screwdriver there. Lot's of noise but I can't really say if it was hissing or bubbling. But something weird happened. My SLT was at 63 just perfect and it wasn't moving. So I thought maybe it was me and I didn't give the gas enough time to circulate. 15 mins go by still perfect and I'm getting ready to put the cover back on and right then the SLT just started dropping all the way to 44. I just shut it down. Unit is 4 yo low on gas so I charged it up by superheat watching the videos. I bled my hoses. Oh well, thank you for your advice and I'll take a bit to think about my next move.
Am a little lost on this one. A good exercise for us newbies would be making diagrams on what's connected where, which end is receiving and supplying pressure, and such.
This one is made for those who are fairly experienced. Will be looking at one that is more explanatory.
GFM
+grayfurnaceman
At your leisure, Doctor G. 😉
can you just say pounds instead of reading psig?
johnny danger I am interested in why you would like "pounds". The reason I use "psig" is to designate the pressure to be zeroed at atmospheric pressure.
GFM