R-22 TO 407C

[valdelocc]

York produced several YCAS units that was shipped with 407c. The only differences I remember seeing was they had a liquid line to suction line heat exchanger, The micro-processor has option built into it to run on either R22 or R407c with just a push of the button. If circumstances warranted it I wouldn't hesitant to convert to R407 including a couple of oil changes.

Why change the oil? I challenged engineers to give me a good reason and none of them could, just because somebody wrote "change the oil" on a piece of paper, doesn't mean you have to do it. R-22 is 33% miscible with mineral oil, the oil separator removes 98% of the 33% oil that travels with the refrigerant, 407c is 4%to 10% miscible with mineral oil and the oil separator removers 98% of the 4% of the oil that travels with the refrigerant,the capacity of the oil separator would be enhanced by an non-miscible refrigerant, in a package chiller the little oil that is carried away by velocity will be brought back by the same forces.

[ryan79]

have you looked into the new MO99 ?

[klove]

Why change the oil? I challenged engineers to give me a good reason and none of them could, just because somebody wrote "change the oil" on a piece of paper, doesn't mean you have to do it. R-22 is 33% miscible with mineral oil, the oil separator removes 98% of the 33% oil that travels with the refrigerant, 407c is 4%to 10% miscible with mineral oil and the oil separator removers 98% of the 4% of the oil that travels with the refrigerant,the capacity of the oil separator would be enhanced by an non-miscible refrigerant, in a package chiller the little oil that is carried away by velocity will be brought back by the same forces.

Have to say that I agree with you for the most part. The only real issue that comes up is the oil that carries out into the condenser is in blobs, sort of like the stuff in an old Lava Lamp, since the oil doesn't mix with the refrigerant. This can lead to somewhat erratic feed thru the expansion valve. Something that can be done to skirt the issue is to drain part of the mineral and replace with POE, since the POE will mix with the mineral and the refrigerant. We've done this and had very good success.

Back to the original question by the OP, unless this is a first run YCAS, it already has POE and shouldn't be an issue.

[sargent york]

Amen to the mineral oil clumping up in high side when using 407c! You can see it in sight glasses!

[jayguy]

Why change the oil? I challenged engineers to give me a good reason and none of them could, just because somebody wrote "change the oil" on a piece of paper, doesn't mean you have to do it...

if you want the unit to work in EVERY case, you need to change the oil. just because it worked OK in your unit and in your application, doesn't mean that it will for people in hotter or colder climates than what you use your unit for. what about an ice arena or ice bank? it may not work there without a change of oil. will the old mineral oil work in the majority of units? probably. but to give wholesale advice saying NOT to change the oil without knowing the application is inappropriate.

oil separator efficiency is not constant. changes in velocity make a big difference. changes in suction superheat change how much oil travels out of the compressor and into the oil separator. number of starts per hour makes a big difference. cleanliness of the condenser makes a big difference in how well the oil travels with the refrigerant, etc.

[valdelocc]

if you want the unit to work in EVERY case, you need to change the oil. just because it worked OK in your unit and in your application, doesn't mean that it will for people in hotter or colder climates than what you use your unit for. what about an ice arena or ice bank? it may not work there without a change of oil. will the old mineral oil work in the majority of units? probably. but to give wholesale advice saying NOT to change the oil without knowing the application is inappropriate.

oil separator efficiency is not constant. changes in velocity make a big difference. changes in suction superheat change how much oil travels out of the compressor and into the oil separator. number of starts per hour makes a big difference. cleanliness of the condenser makes a big difference in how well the oil travels with the refrigerant, etc.

I agree with you! the change or not to change the oil rule applies in some circumstance only!, now that we made such great discovery, I would like to know if changing the refrigerant configuration in the adaptive control would set the machine to run in r134a or 404a mode? with some modifications of course

[Nuclrchiller]

I agree with you! the change or not to change the oil rule applies in some circumstance only!, now that we made such great discovery, I would like to know if changing the refrigerant configuration in the adaptive control would set the machine to run in r134a or 404a mode? with some modifications of course

Are you asking about that RTAA you converted? I'm not so sure I can help with your question, but it would help anyone to know what control panel is on it. If you don't recall that, then what tonnage is it? Or you can describe the panel.

[valdelocc]

Are you asking about that RTAA you converted? I'm not so sure I can help with your question, but it would help anyone to know what control panel is on it. If you don't recall that, then what tonnage is it? Or you can describe the panel.

In the password protected menu there a "refrigerant type" point, the choices are "r22 134a and 404a" if one was to change the settings from r-22 to any of the other 2, would the control reconfigure itself and the chiller to run in such refrigerant?

[Carlos Daniel]

Have to say that I agree with you for the most part. The only real issue that comes up is the oil that carries out into the condenser is in blobs, sort of like the stuff in an old Lava Lamp, since the oil doesn't mix with the refrigerant. This can lead to somewhat erratic feed thru the expansion valve. Something that can be done to skirt the issue is to drain part of the mineral and replace with POE, since the POE will mix with the mineral and the refrigerant. We've done this and had very good success.

Back to the original question by the OP, unless this is a first run YCAS, it already has POE and shouldn't be an issue.

Are you sure what you saying.....because I´ve done retrofits from R22 to R407C, most of the times when the compressor failed and then changed. Even the new compressor comes with POE oil, when we start it, after 2 minutes we could see in the oil sightglass all white, looks like snow, We had to make 2 more changes of oil for it became clear.
My conclusion was R407C does not admit any mineral oil.

Other 2 situations that you should take in care is that when you changed MIN to POE, the POE is more acid then MIN, so it will work as a solvent in refrigerant circuit, all rust will be dissolved in oil, other is, old compressors have the winding not prepared for the POE, it will damage the winding isolation bacause of the same problem.

[valdelocc]

Are you sure what you saying.....because I´ve done retrofits from R22 to R407C, most of the times when the compressor failed and then changed. Even the new compressor comes with POE oil, when we start it, after 2 minutes we could see in the oil sightglass all white, looks like snow, We had to make 2 more changes of oil for it became clear.
My conclusion was R407C does not admit any mineral oil.

Other 2 situations that you should take in care is that when you changed MIN to POE, the POE is more acid then MIN, so it will work as a solvent in refrigerant circuit, all rust will be dissolved in oil, other is, old compressors have the winding not prepared for the POE, it will damage the winding isolation bacause of the same problem.

POE is not acidic,they oil sight glass was "white" cause of the refrigerant traveling with the oil, 407C is 7% miscible with mineral oil. In a chiller equipped with an oil separator, the oil travels by means of pressures differentials.
The compressors windings are the same with POE or MO, POE is a strong solvent thats all.

[GT1980]

There are a few examples of a couple years success on line searching 407 from 22. and you can call those successful comm/inds service cos.

[EMETH]

Why change the oil? I challenged engineers to give me a good reason and none of them could, just because somebody wrote "change the oil" on a piece of paper, doesn't mean you have to do it. R-22 is 33% miscible with mineral oil, the oil separator removes 98% of the 33% oil that travels with the refrigerant, 407c is 4%to 10% miscible with mineral oil and the oil separator removers 98% of the 4% of the oil that travels with the refrigerant,the capacity of the oil separator would be enhanced by an non-miscible refrigerant, in a package chiller the little oil that is carried away by velocity will be brought back by the same forces.

I have heard this before on the limited miscibility of R22 but have not been able to locate citations on this; can you provide sources?

Thanks

[valdelocc]

I have heard this before on the limited miscibility of R22 but have not been able to locate citations on this; can you provide sources?

Thanks

I actually got the numbers from an article written by Wes Taylor, he was an old time RSES member and senior engineer with Carlyle compressors. I dont have a link to it.