30 ton split R-22 to 410a

[allstar08]

30 ton split system using existing 30 year old coils. All lines left in as well as accumulator. Txv's were replaced as well as liquid line solenoids. Suction line filter added and lines blown with nitrogen. How much left over oil in the system is acceptable? The coils had to stay I wish it could have been replaced. Holes were drilled in the traps and taps were added so oil could be drained and blown out with nitro. Thoughts and feelings? Unit is not fired off yet. I am thinking of removing accumulator, and flushing with a flush kit.

[AiResearch]

Pretty sure this is a huge mistake.

[Gibbo]

You need to take a step back and think about this.
UNDER NO CIRCUMSTANCES START THIS UNIT UP WITH R410A.
None of the components will be rated for R410A and are likely to fail using R410A.
If you want to change out R22 then you need to change to a compatible refrigerant USING SIMILAR PRESSURES such as R417A R422D depending on size of unit.

This is an accident waiting to happen.

[SouthTex]

Recently did a conversion on two 20 ton units as the condensers needed replaced. Warned the customer not to do it turns out we were right chasing refrigerant leaks on the indoor coil that were not there when the conversion was done. Big mess

[maxster]

both ends of the system was tested for R-22 now its going to see and feel 410A oil is the least of your problems,rebraze all the lines and do a 1000PSI nitro test maybe:gah: tonnage has to be effected with the higher pressures in what could be considered a low pressure original install

[ga-hvac-tech]

Seems to me a lot of similar refrigerants to R22 are available. I would be seriously worried about the system not handling the higher pressures.

Your prep sounds good... however a refrigerant that both operates at similar pressures and uses mineral oil would be my choice.

Let us know how this works out.

[allstar08]

I will say this job got dropped in my lap to wrap up and fire off. I have checked the majority of all the brazed joints and have a 450 psi test on it right now. I am just trying to make the best of a bad situation. I had heard there were some new schools of thought about actually leaving oil in the system. I am curious if anyone had done it. The job has to be fired of on Tuesday regardless of what I want, it is out of my hands.

[allstar08]

You need to take a step back and think about this.
UNDER NO CIRCUMSTANCES START THIS UNIT UP WITH R410A.
None of the components will be rated for R410A and are likely to fail using R410A.
If you want to change out R22 then you need to change to a compatible refrigerant USING SIMILAR PRESSURES such as R417A R422D depending on size of unit.

This is an accident waiting to happen.

condensing unit is installed and is 410. I think we have to use 410 t this point.

[allstar08]

Recently did a conversion on two 20 ton units as the condensers needed replaced. Warned the customer not to do it turns out we were right chasing refrigerant leaks on the indoor coil that were not there when the conversion was done. Big mess

have you had any acid problems? did you reuse the line sets as well as the coils? did you flush the indoor coils?

[ascj]

I will say this job got dropped in my lap to wrap up and fire off. I have checked the majority of all the brazed joints and have a 450 psi test on it right now. I am just trying to make the best of a bad situation. I had heard there were some new schools of thought about actually leaving oil in the system. I am curious if anyone had done it. The job has to be fired of on Tuesday regardless of what I want, it is out of my hands.

I haven't done a 22 to a 410a conversion using a unknown rated coil. But with that said, I have done conversions from a mineral to a POE refrigerant. From what you have said, I would skip the flush kit, but change the accumulator for good measure.

Why is there is an accumulator? And you only have one......is this a single lineset?

[allstar08]

I haven't done a 22 to a 410a conversion using a unknown rated coil. But with that said, I have done conversions from a mineral to a POE refrigerant. From what you have said, I would skip the flush kit, but change the accumulator for good measure.

Why is there is an accumulator? And you only have one......is this a single lineset?

original with the old system, I don't think it is needed with the new system. safety for low ambient operation I assume, the line set isn't very long.

[acwizard]

Pretty sure this is a huge mistake.

I tend to agree.The coil parameters are not even close between R-22 and 410. As far as accumulators goes, it needs to be resized for the change in refrigerant. Accumulators are inexpensive compared to compressors.These are the types of jobs that any good service company would love to chase. Lots of problems, and there is nothing like doing the job twice.

[ga-hvac-tech]

I tend to agree.The coil parameters are not even close between R-22 and 410. As far as accumulators goes, it needs to be resized for the change in refrigerant. Accumulators are inexpensive compared to compressors.These are the types of jobs that any good service company would love to chase. Lots of problems, and there is nothing like doing the job twice.

Seems I end up doing it the second time... after the first contractor has a phone number change... :whistle:

I appreciate hacks (not referencing anyone)... they make me lots of $$$ :grin2:

[just_opinion]

30 ton split system using existing 30 year old coils. All lines left in as well as accumulator. Txv's were replaced as well as liquid line solenoids. Suction line filter added and lines blown with nitrogen. How much left over oil in the system is acceptable? The coils had to stay I wish it could have been replaced. Holes were drilled in the traps and taps were added so oil could be drained and blown out with nitro. Thoughts and feelings? Unit is not fired off yet. I am thinking of removing accumulator, and flushing with a flush kit.

If you ask this question on the refrigeration forum, they will laugh at it. Because they have done it for years.

Look like you have done your home work on oil flushing. Let her ripe. How many SEER can you loose? This 30 tons comes off the factory with 9 SEER :grin2:.

I agree with you about the accumulator.

[AiResearch]

If you ask this question on the refrigeration forum, they will laugh at it. Because they have done it for years.

Look like you have done your home work on oil flushing. Let her ripe. How many SEER can you loose? This 30 tons comes off the factory with 9 SEER :grin2:.

I agree with you about the accumulator.

Yes they have done refrigerant retrofits , and the replacement gas usually has similiar operating characteristics and pressures.

It is downright foolish to install refrigerant 410a in equipment designed for 22.

It should be a no-brainer.

[acwizard]

If you ask this question on the refrigeration forum, they will laugh at it. Because they have done it for years.

Look like you have done your home work on oil flushing. Let her ripe. How many SEER can you loose? This 30 tons comes off the factory with 9 SEER :grin2:.

I agree with you about the accumulator.

I have never seen a 30 ton rated in SEER, maybe EER. Let her ripe, It certainly will like a bad apple falling from a tree. I will be waiting to see the disaster unfold.

[WorkHardThenDie]

this whole scenario goes against what alot of us have learned.. different pressures .. diff oils .. different manufacturing applications - for 410a .. poe oild tolerates NO OTHER oil .. between evap. acc. how can you be sure its all out before retrofitting? and whats the point of all this .. god forbid this thing goes byebye.. now you back to replacing EVERYTHING .. and at that point you have now costed yourself and customer way more money and time then if you just replaced it which.. like it said .. god forbid.. you may wind up doing neway.. how come i never hear if at all maybe slightly .. why NOONE uses 407c? i may post that question .. i know it fractionates but its what i keep reading is a perfect drop in for r22.. still uses poe i believe tho.. sorry to go off topic .. good luck and please post the result ..

[ga-hvac-tech]

this whole scenario goes against what alot of us have learned.. different pressures .. diff oils .. different manufacturing applications - for 410a .. poe oild tolerates NO OTHER oil .. between evap. acc. how can you be sure its all out before retrofitting? and whats the point of all this .. god forbid this thing goes byebye.. now you back to replacing EVERYTHING .. and at that point you have now costed yourself and customer way more money and time then if you just replaced it which.. like it said .. god forbid.. you may wind up doing neway.. how come i never hear if at all maybe slightly .. why NOONE uses 407c? i may post that question .. i know it fractionates but its what i keep reading is a perfect drop in for r22.. still uses poe i believe tho.. sorry to go off topic .. good luck and please post the result ..

I wonder about the R-407 also... given the pressures being very similar. MeThinks it is about the cost of refrigerant...

I hope it works... if not... Some sales guy and/or co guy(s) will be 'on the hook' so to say.

I do remember reading the OP is not the decision maker... rather the worker-bee... lets not crucify the worker for doing as he was told.

Please DO let us know what happens... THX!

[ascj]

poe oil tolerates NO OTHER oil I would disagree....a little mineral or allylbenzene is finewhy NOONE uses 407c? Tons of manufactures and contractors use it.....only manufacture that has a problem with it is Carrier(wonder why?)i know it fractionates but its what i keep reading is a perfect drop in for r22It's not perfect but very good.....there are others that claim better, but don't have much experience with them.

Last I checked 410a and 407c is not far off in price.

[allstar08]

it's up and running! cycling and doing just fine. I will keep you posted on how it lasts.

[AiResearch]

Interesting. I guess it would cycle considering the pounds per hour of refrigerant circulated -vs- 22.

The capacity may have went up significantly.

It may end up like swiss cheese shortly.

We have trouble keeping gas in equip. designed for 22 running 22.

Good Luck~

[ga-hvac-tech]

Interesting. I guess it would cycle considering the pounds per hour of refrigerant circulated -vs- 22.

The capacity may have went up significantly.

It may end up like swiss cheese shortly.

We have trouble keeping gas in equip. designed for 22 running 22.

Good Luck~

Yeah, I am interested to hear what issues this repair/upgrade/modification encounters.

AirResearch.. For those of us that do not work with large equipment.. what is that in your avatar (picture) THX.

[AiResearch]

Yeah, I am interested to hear what issues this repair/upgrade/modification encounters.

AirResearch.. For those of us that do not work with large equipment.. what is that in your avatar (picture) THX.

That is a variable pitch vaneaxial fan manufactured by Joy.

They can be used for conditioned supply air or ventilation.

They have high static pressure and volume capabilities.

Generally applied when airflows and pressures exceed 40,000 cfm or more and 3.5 in. or more.

Straight line airflow and use less space than a housed backward incline fan.

Vanes downstream of the fan blades will staighten the circular air motion before entering the duct.

Seen a few , never touched one.

[kneehigh]

Interesting thread, how is the equipement operating. An update would be great!

[jiffypop]

What's the address and startup date, I want to see this!

[allstar08]

Well things were working well, then compressor noise started recently, and then mechanical failure. Looks as if Trane is having some problems with their 15 ton scrolls. The factory is running out of them, there have been several replacements around the country. I have to replace both compressors, Trane is covering the compressors, but not any labor allowance. Has anybody else run into this?

[Rifenme]

Have you thought about the new lubricant? It will wash all the old wax left over from the mineral oil into the expansion devices. The higher pressures are also a huge concern.

[beenthere]

Moved to Tech to Tech commercial forum.

[Dallas Duster]

Last I checked 410a and 407c is not far off in price.

How about today's prices?

[alcomech]

I guess that that my prayer for you is a little too late. But now you must continue with a little hope.
As for the failure this was to be expected. As the others have stated, R-22 and 410A components should never be mixed. The equipment is not interchangeable. You now have a monster out of control.
It sounds like you have a tandem scroll compressor arrangement which will normally require replacement of both compressors. Sounds easy enough Huh?

I don't think so. Your compressor failed because a lack of oil. This was evident from the noise and the locking up of the scrolls. Now you will have to first clean up the mess. There are now fine metal micron fragments in the system which must be removed or expect another quick failure. You know the routine with a high capacity clean up suction filter/drier. You will also need to perform an acid test.

Having left behind some mineral oil and mixing with POE oil has resulted in the form of two liquids. This is a direct result of oil loss.

As for the remedy you will need to consider operation in a part loaded condition. The installation of a hot gas bypass line will need to be installed so that proper circulation of oil can be maintained and returned to the compressor. Liquid line size will need to be evaluated so as to maintain a minimum velocity of 260 feet per minute and a recommended maximum of 400 feet per minute. Suction Line size may need to be at least 1-5/8 or maybe even 2-1/8 so as to maintain proper oil return

REMEMBER: With 2 stage units you must look at the suction line velocity at reduced capacity to insure velocity remains above 1000fpm on suction risers. If it does not, reducing the riser size by one size will correct the problem


I will send you a sizing chart as an example for your use in the next post:
If you want I can email it as an excel file.

In addition I would remove the suction accumulator and install one sized correctly for your application. It sounds like you have a single circuit with one TXV.

The other problem that you will have is that when one compressor is running it will have the tendency to draw oil from the compressor which is off by means of oil misting. You will have to install a crankcase heater and possibly two so as to prevent this from happening.

The head pressure will also need to be maintained at a minimum set point and controlled by a speed controller such as a Penn/Johnson VFD 66 Drive and with the use of a pressure transducer P499.

I can go on but not tonight.

Troubleshooting is not part of the repair..............understand the symptoms and you will find a solution.

[mikeacman]

I know of some that were supposed to have POE and accidentally shipped with mineral ....

Trans paid 100% and provided the labor as well....

Shhhhhh....

[mikeacman]

I think the biggest point missed here is R22 equipment and components are NOT safety rated for the higher pressure of R410a...

I'm converting my service van from gasoline to diesel to save money ...any ideas ....

Everybody who continues to perform work like this ,thanks for the future work....

And yes ,I know the OP.had his hands tied ,,,as I have in in the past....

[beenthere]

I think the biggest point missed here is R22 equipment and components are NOT safety rated for the higher pressure of R410a...

I'm converting my service van from gasoline to diesel to save money ...any ideas ....

Everybody who continues to perform work like this ,thanks for the future work....

And yes ,I know the OP.had his hands tied ,,,as I have in in the past....

The evap coils that were made 30 years go, and most other evap coils made pre 13 SEER min were made thicker then a coil made/rated for R410A today.
Line sets today, aren't made any thicker then line sets 10, 20, 30 or more years ago.

The condenser coil of a new R410A unit has a thinner wall then the old evap coils do.

[mikeacman]

Your more than likely correct ...

but they still aren't rated from a liability standpoint ...
most evaps like that I've seen are pressure rated at 150 to 300 psig .
Dump a full charge in a room from a blowout and make people sick and see what happens when lawyers get involved....
That will never happen .... Famous last words

Absolutely no disrespect intended ,just my personal opinion

[mikeacman]

And with R22 options why go 410a???

[dunkman]

Well things were working well, then compressor noise started recently, and then mechanical failure. Looks as if Trane is having some problems with their 15 ton scrolls. The factory is running out of them, there have been several replacements around the country. I have to replace both compressors, Trane is covering the compressors, but not any labor allowance. Has anybody else run into this?

Thank you for this thread, it's been educational.

[beenthere]

Your more than likely correct ...

but they still aren't rated from a liability standpoint ...
most evaps like that I've seen are pressure rated at 150 to 300 psig .
Dump a full charge in a room from a blowout and make people sick and see what happens when lawyers get involved....
That will never happen .... Famous last words

Absolutely no disrespect intended ,just my personal opinion

They were only tested to that pressure since with R22 higher wasn't needed. Doesn't mean they could take more. And York and some other manufacturers admit they simply took their old r22 designed evap coils and retested them at higher pressure. they held, and they said ok, they're R410A rated. So a blow out wouldn't be as liable as you may think. As far as because it was from an "unapproved" coil. Same liability as a listed R410A coil.

Why stick with R22, when its becoming more and more expensive.

[mikeacman]

Never said stick with R22,,,I said there are other options out there ....

Being called in the office one day with several other techs and being told that we were being sued over something we considered frivolous , or no big deal, has made me a little gun-shy..

[Shophound]

Well things were working well, then compressor noise started recently, and then mechanical failure. Looks as if Trane is having some problems with their 15 ton scrolls. The factory is running out of them, there have been several replacements around the country. I have to replace both compressors, Trane is covering the compressors, but not any labor allowance. Has anybody else run into this?

Did you hear "looks as if Trane is having problems with their 15 ton scrolls" directly from Trane? Or is this wishful thinking/supply house rumor?

I think your words above would have more street cred if these 15 ton scroll failures were occurring in brand new 410A systems (the entire system, including evap, coils, linesets) at a rapid pace, systems that had not been converted from R22. Perhaps they are, but I personally would be asking that question were I told "we're seeing a lot of failures with these 15 ton scrolls and the factory is running of them" with no other qualifiers.

In your case I'm wondering if some time and $$ spent on RX11 flush may have made the difference between your scrolls failing or staying alive.

[Jimmyhat 597]

Sounds like a job bid by someone with just enough knowledge to put the car in Drive but not enough to check the brakes. Any AC DX job with an Accumulator or an Oil sep. Is a bad system wich has been band aided already suggest T&M only

[allstar08]

Did you hear "looks as if Trane is having problems with their 15 ton scrolls" directly from Trane? Or is this wishful thinking/supply house rumor?

I think your words above would have more street cred if these 15 ton scroll failures were occurring in brand new 410A systems (the entire system, including evap, coils, linesets) at a rapid pace, systems that had not been converted from R22. Perhaps they are, but I personally would be asking that question were I told "we're seeing a lot of failures with these 15 ton scrolls and the factory is running of them" with no other qualifiers.

In your case I'm wondering if some time and $$ spent on RX11 flush may have made the difference between your scrolls failing or staying alive.

I heard it on this site and around the water cooler. I know what you are getting at, and I see your point. None the less I have heard mutterings about the compressors made south of the border and how they perform running 410. Why else would it take over a month to get replacements? I can call my local supplier and can count on my right hand how many times they have not had a compressor, including the three of these I have ordered.

If you read the Trane installation manual it does not recommend using R-11 flush kits.

[allstar08]

I guess that that my prayer for you is a little too late. But now you must continue with a little hope.
As for the failure this was to be expected. As the others have stated, R-22 and 410A components should never be mixed. The equipment is not interchangeable. You now have a monster out of control.
It sounds like you have a tandem scroll compressor arrangement which will normally require replacement of both compressors. Sounds easy enough Huh?

I don't think so. Your compressor failed because a lack of oil. This was evident from the noise and the locking up of the scrolls. Now you will have to first clean up the mess. There are now fine metal micron fragments in the system which must be removed or expect another quick failure. You know the routine with a high capacity clean up suction filter/drier. You will also need to perform an acid test.

Having left behind some mineral oil and mixing with POE oil has resulted in the form of two liquids. This is a direct result of oil loss.

As for the remedy you will need to consider operation in a part loaded condition. The installation of a hot gas bypass line will need to be installed so that proper circulation of oil can be maintained and returned to the compressor. Liquid line size will need to be evaluated so as to maintain a minimum velocity of 260 feet per minute and a recommended maximum of 400 feet per minute. Suction Line size may need to be at least 1-5/8 or maybe even 2-1/8 so as to maintain proper oil return

REMEMBER: With 2 stage units you must look at the suction line velocity at reduced capacity to insure velocity remains above 1000fpm on suction risers. If it does not, reducing the riser size by one size will correct the problem


I will send you a sizing chart as an example for your use in the next post:
If you want I can email it as an excel file.

In addition I would remove the suction accumulator and install one sized correctly for your application. It sounds like you have a single circuit with one TXV.

The other problem that you will have is that when one compressor is running it will have the tendency to draw oil from the compressor which is off by means of oil misting. You will have to install a crankcase heater and possibly two so as to prevent this from happening.

The head pressure will also need to be maintained at a minimum set point and controlled by a speed controller such as a Penn/Johnson VFD 66 Drive and with the use of a pressure transducer P499.

I can go on but not tonight.

Troubleshooting is not part of the repair..............understand the symptoms and you will find a solution.

I can tell you love this stuff. Thanks for the input.
System has hot gas bypass and two txv's. Each txv has a check valve and a liquid line solenoid.
Compressors come with 1 1/8 equalizing line between them. There is a head pressure control, a Trane original, a damper controlled by an actuator on top of the fan discharge.

[Cmstech]

Never let the customer, your company, or anyone else cause you to sacrifice your integrity and quality of work.

[Armament]

I find this thread very interesting. Everyone seems to be incredibly worried about the "components" not being rated for 410. I don't like Soft tubing running 410a, 500psi behind flares and new thin aluminum coils because they're cheaper to make but manufactuers seem to think this is still dandy. Are the coils 30 years ago really not rated for the higher pressures? Liability aside I'd be very interested to see if anyone has proof that the coils are (and I repeat in reality) not able to withstand 410A. As mentioned yes, not rated for 410 but when it the age where it was unrealistic to rate a coil for that pressure why would they?

I do understand the concern over liability and there is something to be said if another company (which can be compared to some of the worry warts in this thread) came in and started running their mouth about how it's not a 410 coil. Is type m copper? Is it still silphos? Yeah ok, if the coil is soft solder I understand. The evaporator and the existing piping is the only issue.

It's recommended (by dupont anyways) that it have no more than a 5% mineral oil left in the system. Drilling the traps was a good idea. Definitely changing the suction accumulator. My "personal" opinion is that this thread is filled with a slight air of hysteria but we all know what they say about opinions :whistle: . There is always the "absolute right" thing to do but frankly in some cases it's unrealistic in financial terms. You could have had a coil to match that air handler manufactured, repiped the entire run and done it that way but was that realistic? Is it still going to work in the fashion you described?

Time will tell. :)

[cy]

interesting thread....

[allstar08]

I agree, I have never been concerned with the integrity of the components. I have been concerned with the need of the accumulator. The indoor coil is in the basement and the outdoor unit is about 8-10ft above it. I don't think we even need it.

[alcomech]

I find this thread very interesting. Everyone seems to be incredibly worried about the "components" not being rated for 410. I don't like Soft tubing running 410a, 500psi behind flares and new thin aluminum coils because they're cheaper to make but manufactuers seem to think this is still dandy. Are the coils 30 years ago really not rated for the higher pressures? Liability aside I'd be very interested to see if anyone has proof that the coils are (and I repeat in reality) not able to withstand 410A. As mentioned yes, not rated for 410 but when it the age where it was unrealistic to rate a coil for that pressure why would they?

I do understand the concern over liability and there is something to be said if another company (which can be compared to some of the worry warts in this thread) came in and started running their mouth about how it's not a 410 coil. Is type m copper? Is it still silphos? Yeah ok, if the coil is soft solder I understand. The evaporator and the existing piping is the only issue.

It's recommended (by dupont anyways) that it have no more than a 5% mineral oil left in the system. Drilling the traps was a good idea. Definitely changing the suction accumulator. My "personal" opinion is that this thread is filled with a slight air of hysteria but we all know what they say about opinions :whistle: . There is always the "absolute right" thing to do but frankly in some cases it's unrealistic in financial terms. You could have had a coil to match that air handler manufactured, repiped the entire run and done it that way but was that realistic? Is it still going to work in the fashion you described?

Time will tell. :)

So what are you trying to say about preventing a future failure. Its obvious that he has an issue. It is true that its any one's guess as to why he has experienced such a sudden failure, but unless he covers the basics- it is guaranteed that it will happen again..
As for myself I am not concerned with the fact that its a mismatched system, however if the components are not compatible they must then be replaced. It is not likely that his piping is type "M" copper and most likely it is at least type "L".

There are not too many people here blurting.... just stating the facts.
To down play this situation at hand and to not give a positive solution is not "realistic".

Trouble shooting is not part of the repair..........understand the symptoms and you will find a solution.

[Ohio 614]

Had a customer that did this. We gave them a quote to replace the evap coils but they went with a mom and pop operation that reused everything except the txv's. Well, 4 compressor replacements later I think it has finally run for 3 months straight. I noticed the suction line is always warm but I won't work on it because this customer is one of those that thinks " you touched it, its your problem now".

[Jimmyhat 597]

Salesman called me asked why i figured so much time to replace a compresser on a Desert Air unit. Says another shop beat us by 2k
"first I never saw it run, the customers maint. condemed it. Unit should be replaced. Every time I work there the Maintanence staff tells me how sharp they are and why am I here. Good luck to who got it" I figured 2 days for making it work right but go ahead cut the bid I'll slap a new Comp in and hit the button and walk away then wait for the customer wanting warranty after maint staff works on it.

[toocoolforschool]

Salesman called me asked why i figured so much time to replace a compresser on a Desert Air unit. Says another shop beat us by 2k
"first I never saw it run, the customers maint. condemed it. Unit should be replaced. Every time I work there the Maintanence staff tells me how sharp they are and why am I here. Good luck to who got it" I figured 2 days for making it work right but go ahead cut the bid I'll slap a new Comp in and hit the button and walk away then wait for the customer wanting warranty after maint staff works on it.
I think this is a new thread

[B1978]

I ran into this situation. Another contractor had the factory approve the huge slab coils from 22 to 410A. I went higher up and had it looked at and they said no. I quoted it the right way and lost out. Now its someone elses mess for life!
Didnt make the money from the job, but we also didnt risk the consequences of a lifetime of leaks.
Keep us updated if things start going bad?
You can also have a custom coil built once this one fails, etc.

[dunkman]

Had a customer that did this. We gave them a quote to replace the evap coils but they went with a mom and pop operation that reused everything except the txv's. Well, 4 compressor replacements later I think it has finally run for 3 months straight. I noticed the suction line is always warm but I won't work on it because this customer is one of those that thinks " you touched it, its your problem now".

Ha! Aren't they all???