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Old 08-29-2020, 08:19 AM   #31
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Re: recharging question for r22


You let it keep running like that, your compressor isn’t long to live. And you’ll be shopping for a new system.
I don’t understand why your allowing the system to keep running this way, instead of fixing the problem.
This isn’t how to leak check, or determine the size of the leak.
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Old 08-29-2020, 08:32 AM   #32
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Re: recharging question for r22


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Originally Posted by roughneck View Post
You let it keep running like that, your compressor isn’t long to live. And you’ll be shopping for a new system.
I don’t understand why your allowing the system to keep running this way, instead of fixing the problem.
This isn’t how to leak check, or determine the size of the leak.
so tell me what reply your referring to. so i know what your talking about

we are getting so deep into this the info is getting messed up. go to # 30 and then repay to that so we will then be on the same page. thanks
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Old 08-29-2020, 08:43 AM   #33
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Re: recharging question for r22


There is no specific pressures the unit should run at. The charging chart is just for a rough idea. It must be then fine tuned.
The pressures and temperatures you quotes in that post, are going to cause compressor damage. And lead to compressor failure.
You have not taken SH/SC yet?
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Old 08-29-2020, 09:02 AM   #34
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Re: recharging question for r22


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Originally Posted by roughneck View Post
There is no specific pressures the unit should run at. The charging chart is just for a rough idea. It must be then fine tuned.
The pressures and temperatures you quotes in that post, are going to cause compressor damage. And lead to compressor failure.
You have not taken SH/SC yet?
i guess i do not know how to do that then. i know running it is going to ruin it that is why i posted the topic to get an idea if what i want to do is good or not. plus all i have to go by is that chart. and the tools i have. i will just try recharging it and monitor pressures on the same temp days and see if it looses pressure again. plus today when i do another pressure test i will also put soap bubbles on the hi side line i did the fittings already and they are good and the evap is good. thanks for the ideas and the help
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Old 08-29-2020, 09:12 AM   #35
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Re: recharging question for r22


As has been said before you will not be able to do a leak down test how you think you can. You will not see the system “loose pressure” on “same temperature days”. It doesn’t work like that.
You really need to get a proper set of gauges. That one doesn’t have the correct scale. And the shaded areas for different refrigerants are worthless. Hope your not using them. Both sides of the system should be monitored while charging.
You need to verify SH. And make sure you aren’t slugging liquid.
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Old 08-29-2020, 09:27 AM   #36
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Re: recharging question for r22


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As has been said before you will not be able to do a leak down test how you think you can. You will not see the system “loose pressure” on “same temperature days”. It doesn’t work like that.
You really need to get a proper set of gauges. That one doesn’t have the correct scale. And the shaded areas for different refrigerants are worthless. Hope your not using them. Both sides of the system should be monitored while charging.
You need to verify SH. And make sure you aren’t slugging liquid.
thanks for the ideas. i will be able to see bubbles with the system running on the high side. a set of gages will not tell me anything different that the gage i have. the only difference is i can only do one side. all you do with gages is one side at a time. plus with gages set i have the same issue with different days.

at this point i have nothing to loose. i was asking about using sealer and putting in a bit of oil and you suggested to not do that so i'm all set now. i will get me a can of r22 and try it and if the unit runs it runs if it fails hey it is 31 years old and may be time to retire it i guess. thanks for the help
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Old 08-29-2020, 10:09 AM   #37
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Re: recharging question for r22


the increments on your gauge are too far apart, you can't use it with any degree of accuracy.
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Old 08-29-2020, 11:02 AM   #38
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Re: recharging question for r22


I was in a similar situation several years ago. I had a leak in my evaporator coil that could not be repaired. The cost to replace it was $1600 + tax=$1730.00, ouch. I purchased r22 in 10 lb tank for $160. (I had to sign a waiver that it would be installed by a licensed tech). I paid a tech $60 to install.
Hope this helps.
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Old 08-29-2020, 11:16 AM   #39
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Re: recharging question for r22


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I was in a similar situation several years ago. I had a leak in my evaporator coil that could not be repaired. The cost to replace it was $1600 + tax=$1730.00, ouch. I purchased r22 in 10 lb tank for $160. (I had to sign a waiver that it would be installed by a licensed tech). I paid a tech $60 to install.
Hope this helps.
But what about the leaking coil?
It’s actually illegal in some areas to charge a known leaking system without repairing the leak. I believe Canada is this way.

Last edited by roughneck; 08-29-2020 at 11:38 AM.
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Old 08-29-2020, 11:20 AM   #40
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Re: recharging question for r22


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Originally Posted by Gary_F View Post
I was in a similar situation several years ago. I had a leak in my evaporator coil that could not be repaired. The cost to replace it was $1600 + tax=$1730.00, ouch. I purchased r22 in 10 lb tank for $160. (I had to sign a waiver that it would be installed by a licensed tech). I paid a tech $60 to install.
Hope this helps.
thanks gary. and he most likely put in sealer! i'm going to go down that same road. i can charge it myself. the first go around if it works and then stops working i know for sure it is leaking. today i will test it again and do a super heat test and also before i start it up put soap on the lines to see if i find any bubbles. hard to do the evap and cond. the cond looks good with no corrosion so it may be just fine. the evap looks ok no corrosion on my side but who know on the back side and where it sets in the water pan. could have worked a hole there. and where it goes thru the wall it may have rubbed from movement over the years. my money is that spot. so i have to figure out how to get sopa in that area. anyway your way might just be my way as well.

if i do find a leak i will ask the local service guys and send pictures and see how they would fix it. some may resolder it some may use sealer. thanks
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Old 08-29-2020, 11:26 AM   #41
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Re: recharging question for r22


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Originally Posted by corvairbob65 View Post
thanks gary. and he most likely put in sealer! i'm going to go down that same road. i can charge it myself. the first go around if it works and then stops working i know for sure it is leaking. today i will test it again and do a super heat test and also before i start it up put soap on the lines to see if i find any bubbles. hard to do the evap and cond. the cond looks good with no corrosion so it may be just fine. the evap looks ok no corrosion on my side but who know on the back side and where it sets in the water pan. could have worked a hole there. and where it goes thru the wall it may have rubbed from movement over the years. my money is that spot. so i have to figure out how to get sopa in that area. anyway your way might just be my way as well.

if i do find a leak i will ask the local service guys and send pictures and see how they would fix it. some may resolder it some may use sealer. thanks
In your case it would not be if it’s leaking, but where. Units don’t just need a charge. The system is sealed.
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Old 08-29-2020, 11:27 AM   #42
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Re: recharging question for r22


no one is going for fix a leak on a 30+ year old unit unless it's something simple like a bad schrader valve. it's not worth it.

budget for a new system.

if you charge it and put a sealant to buy time, be sure not to introduce any air in from the hoses, they have to be purged with refrigerant first. especially with a sealer, you do not want to introduce any moisture in.
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Old 08-29-2020, 12:27 PM   #43
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Re: recharging question for r22


Quote:
Originally Posted by corvairbob65 View Post
thanks gary. and he most likely put in sealer! i'm going to go down that same road. i can charge it myself. the first go around if it works and then stops working i know for sure it is leaking. today i will test it again and do a super heat test and also before i start it up put soap on the lines to see if i find any bubbles. hard to do the evap and cond. the cond looks good with no corrosion so it may be just fine. the evap looks ok no corrosion on my side but who know on the back side and where it sets in the water pan. could have worked a hole there. and where it goes thru the wall it may have rubbed from movement over the years. my money is that spot. so i have to figure out how to get sopa in that area. anyway your way might just be my way as well.

if i do find a leak i will ask the local service guys and send pictures and see how they would fix it. some may resolder it some may use sealer. thanks
No leak sealer. I live in San Antonio area USA
Not concerned about losing 2 lbs a year, just top off ever spring. 2x$16=$32

Last edited by Gary_F; 08-29-2020 at 12:32 PM.
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Old 08-29-2020, 01:04 PM   #44
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Re: recharging question for r22


so to do a superheat i need the evap temp and the outside temp. i should have the wet bulb but i did not have that tool nor the chart to figure that. but the humidity was 70% that day. going by this chart what suction pressure would you figure it to be?

the way i read this chart is left side is the outside temp at unit the center section to the right is the pressures i should be seeing and the top line is the evap suction pressure? correct if is the if i had 75 outside temp and low side pressure of 45# then i would be off the chart to the left side of the center part of that chart. am i correct

using an app i got i had 70 deg low side and 40 pse and the app said superheat of 34.12 deg so what would the low side then have to be? if i take 34 deg form 70 deg at the service port i would have 36 deg. if i add it to the 70 deg at the low side service port i have 104. if i'm to use the 36 deg for super heat then the chart tells me i need to add lots of r22 to even get to the lowest temp on the chart.

so tell me if this is correct? thanks
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Old 08-29-2020, 02:20 PM   #45
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Re: recharging question for r22


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so to do a superheat i need the evap temp and the outside temp. i should have the wet bulb but i did not have that tool nor the chart to figure that. but the humidity was 70% that day. going by this chart what suction pressure would you figure it to be?

the way i read this chart is left side is the outside temp at unit the center section to the right is the pressures i should be seeing and the top line is the evap suction pressure? correct if is the if i had 75 outside temp and low side pressure of 45# then i would be off the chart to the left side of the center part of that chart. am i correct

using an app i got i had 70 deg low side and 40 pse and the app said superheat of 34.12 deg so what would the low side then have to be? if i take 34 deg form 70 deg at the service port i would have 36 deg. if i add it to the 70 deg at the low side service port i have 104. if i'm to use the 36 deg for super heat then the chart tells me i need to add lots of r22 to even get to the lowest temp on the chart.

so tell me if this is correct? thanks

Nope. Not correct.

The term "superheat" means the difference between what the actual temperature of the copper pipe is, and the temperature of what a "pressure temperature chart" says the refrigerant is supposed to be (also known as "saturated temperature").

Example... P.T. chart says refrigerant is at 35°F. Actual suction pipe temperature is 48°F. SH=13°.

Subcooling is the opposite, and is found on the liquid line. Superheat is how much warmer the refrigerant is than what the chart says it's supposed to be. Subcooling is the amount colder it is compared to the chart.

Systems that have piston metering devices should always charged by superheat, while systems with TXV's should be charged by subcooling (and then superheat should be checked to make sure the expansion valve is adjusted correctly). It can get a little complicated, and in my opinion piston units are a little harder to get dialed in than TXV systems are. Especially if you don't have a way to measure indoor wet bulb.

Last edited by bfrabel; 08-29-2020 at 02:32 PM.
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