Is POE bad for R407C ?

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19-12-2008, 07:00 PM
Acrisoft

Is POE bad for R407C ?

I read some scientific articles that states POE is the right lubrificant for R407C.

Now, I found an article that states the other way around.

I would like you guys opinon about the lines below

Moises

(1) Avoids use of POE:
(a) Lower costs: POE lubricants cost some 4 or 5 times more than mineral (MO) & alkyl benzene (AB) oils.
(b) No moisture pick up: POE lubricants are very hygroscopic which causes corrosion of the system.
(c) Production lines using mineral oil would require no changes either in equipment or lubricant
(d) No changes in assembly time with the compressor open to atmosphere

Article from: refsols..com
19-12-2008, 07:16 PM
nike123

Re: Is POE bad for R407C ?

On same site:
Lubricants

RS-45 is suitable for use with mineral, alkylbenzene & polyol ester lubricants. R134a, R407C & R410A should not be used with MO & AB oils.

http://www.refsols.com/RS-45_OEM.html

http://refrigerants.dupont.com/Suva/...suva407c.html#
19-12-2008, 07:29 PM
Acrisoft

Re: Is POE bad for R407C ?

Thanks for quick reply. Now I understood.

So, is R434A a good choice, rather than R407 when retrotifing from R22 ?
19-12-2008, 08:07 PM
nike123

Re: Is POE bad for R407C ?

Quote:

Originally Posted by Acrisoft

Thanks for quick reply. Now I understood.

So, is R434A a good choice, rather than R407 when retrotifing from R22 ?

For retrofitting, best choice, for air conditioning purpose, is still R407.
But, there is available some drop-ins. I personally don't have any experience with drop-ins.
Search this forum for drop-ins. There are some good posts about that subject.

http://www.refrigeration-engineer.co...php/t-661.html
http://www.refrigeration-engineer.co...hlight=drop-in
19-12-2008, 08:19 PM
jcook1982

Re: Is POE bad for R407C ?

I work in ultra low. We use AB oil with 407C/ or 407 D. We use HPLC Grade Pentane as a sweeping agent to keep the Oil and Refrigerant from mixing.
19-12-2008, 08:36 PM
nike123

Re: Is POE bad for R407C ?

Quote:

Originally Posted by jcook1982

I work in ultra low. We use AB oil with 407C/ or 407 D. We use HPLC Grade Pentane as a sweeping agent to keep the Oil and Refrigerant from mixing.

Main reason for "refrigerant oil compatibility" is ability of refrigerant to mix with oil and carry oil back to compressor where it belongs.
So use of something to keep oil and refrigerant from mixing is stupid.
In your case, HPLC Grade Pentane is used to swept oil and carry oil back in compressor instead of R407 (because of his bad miscibility with AB oil).
22-12-2008, 03:34 PM
jcook1982

Re: Is POE bad for R407C ?

Quote:

Originally Posted by nike123

Main reason for "refrigerant oil compatibility" is ability of refrigerant to mix with oil and carry oil back to compressor where it belongs.
So use of something to keep oil and refrigerant from mixing is stupid.
In your case, HPLC Grade Pentane is used to swept oil and carry oil back in compressor instead of R407 (because of his bad miscibility with AB oil).

Why would you want oil to get into your evaporator? Keeping oil out of refrigerant will keep your evaporator from becoming oil logged or you cap tubes from getting clogged with wax in the oils. The sweeping agent keeps the oil flowing in a circuit dedicated to oil going back the compressor bringing a high level of sustainability to your compressor. :cool:
22-12-2008, 03:36 PM
jcook1982

Re: Is POE bad for R407C ?

all depends on the context my. No need to get all demeaning about it NIke
24-09-2009, 03:37 AM
michaelm

Re: Is POE bad for R407C ?

Quote:

Originally Posted by nike123

Main reason for "refrigerant oil compatibility" is ability of refrigerant to mix with oil and carry oil back to compressor where it belongs.
So use of something to keep oil and refrigerant from mixing is stupid.
In your case, HPLC Grade Pentane is used to swept oil and carry oil back in compressor instead of R407 (because of his bad miscibility with AB oil).

NIKE123,

Would HPLC Grade Pentane work with any type refrigerant and oils to help oil to come back to compressor?
24-09-2009, 10:25 AM
norseman

Re: Oil return

Logging has been a problem on ultra low temperature freezers due to the sub cooled refrigerant working for the low stage. In earlier days back 20 Years or more, several makers of ULT units used Pentane to bring back the oil from the capillary tubes. It works like a solvent. Several makers was concerend by the "feature" of the Pentane in the way that it collect moisture very fast from any opened dewar who contains it. The way to fill it into the system should be by feeding it through a filterdryer. A lot of hassle and also difficult to measure the amount. Most makers have the last 20Years or more used Propane R290 as the "solvent". The hydrocarbon works very good to dissolve oil which layer up into cold cap. tubes. Strange to see that Pentane is still used instead of the easy go Propane. I remember without working with commercial or bigger system that at the time the blends was into the market, many was into huge problems since big evaporators had a lot of oil trapped. The new blends had some R290 Propane into the mix: after a retrofit, the all oil got back due to the Propane and filled up the compressors to the neck with returning oil.
Anyway, Propane never let you down on oil return and you really dont need to much to make the wonder to happen.:D Pedro
24-09-2009, 02:45 PM
michaelm

Re: Oil return

Quote:

Originally Posted by norseman

Logging has been a problem on ultra low temperature freezers due to the sub cooled refrigerant working for the low stage. In earlier days back 20 Years or more, several makers of ULT units used Pentane to bring back the oil from the capillary tubes. It works like a solvent. Several makers was concerend by the "feature" of the Pentane in the way that it collect moisture very fast from any opened dewar who contains it. The way to fill it into the system should be by feeding it through a filterdryer. A lot of hassle and also difficult to measure the amount. Most makers have the last 20Years or more used Propane R290 as the "solvent". The hydrocarbon works very good to dissolve oil which layer up into cold cap. tubes. Strange to see that Pentane is still used instead of the easy go Propane. I remember without working with commercial or bigger system that at the time the blends was into the market, many was into huge problems since big evaporators had a lot of oil trapped. The new blends had some R290 Propane into the mix: after a retrofit, the all oil got back due to the Propane and filled up the compressors to the neck with returning oil.
Anyway, Propane never let you down on oil return and you really dont need to much to make the wonder to happen.:D Pedro

B"H

Thank you Pedro,

In what proportion propane/refrigerant you should add it to the system? Would you do it with semi-hermetic compressor?
Regards.
24-09-2009, 02:48 PM
jcook1982

Re: Is POE bad for R407C ?

Quote:

Originally Posted by nike123

On same site:
Lubricants

RS-45 is suitable for use with mineral, alkylbenzene & polyol ester lubricants. R134a, R407C & R410A should not be used with MO & AB oils.

http://www.refsols.com/RS-45_OEM.html

http://refrigerants.dupont.com/Suva/...suva407c.html#

Dupont says here "[IMG]file:///C:/DOCUME%7E1/JCOOK%7E1.SEE/LOCALS%7E1/Temp/moz-screenshot.png[/IMG][IMG]file:///C:/DOCUME%7E1/JCOOK%7E1.SEE/LOCALS%7E1/Temp/moz-screenshot-1.png[/IMG]Q: What type lubricant should be
used with R-407C?
A: A high-quality POE (polyol ester) lubricant is
recommended. Always consult the compressor
or system OEM.":rolleyes:
24-09-2009, 02:52 PM
jcook1982

Re: Is POE bad for R407C ?

Quote:

Originally Posted by michaelm

NIKE123,

Would HPLC Grade Pentane work with any type refrigerant and oils to help oil to come back to compressor?

It's Always important to refer back to what the Manufacturer of the product recommends. Go back to the compressor or system manufacturer to get the data!!:)
24-09-2009, 03:09 PM
jcook1982

Re: Is POE bad for R407C ?

Quote:

Originally Posted by nike123

On same site:
Lubricants

RS-45 is suitable for use with mineral, alkylbenzene & polyol ester lubricants. R134a, R407C & R410A should not be used with MO & AB oils.

http://www.refsols.com/RS-45_OEM.html

http://refrigerants.dupont.com/Suva/...suva407c.html#

We have been using R407D in our systems since the early 90's with no problems. R407 D is 70% R134A and 30% R410A. R407C is 52% R134A and 48% R410A. The oil we use is AB very similar to Zerol 150.
We have had no problems with this mix RSL web site has no basis for these statements besides the fact that Dupont says what is recommended. Dupont also says that you should refer to compressor manufacturer or system manufacturer specifications on oil...:o
24-09-2009, 05:24 PM
cryogentech

Re: Oil return

Quote:

Originally Posted by norseman

Logging has been a problem on ultra low temperature freezers due to the sub cooled refrigerant working for the low stage. In earlier days back 20 Years or more, several makers of ULT units used Pentane to bring back the oil from the capillary tubes. It works like a solvent. Several makers was concerend by the "feature" of the Pentane in the way that it collect moisture very fast from any opened dewar who contains it. The way to fill it into the system should be by feeding it through a filterdryer. A lot of hassle and also difficult to measure the amount. Most makers have the last 20Years or more used Propane R290 as the "solvent". The hydrocarbon works very good to dissolve oil which layer up into cold cap. tubes. Strange to see that Pentane is still used instead of the easy go Propane. I remember without working with commercial or bigger system that at the time the blends was into the market, many was into huge problems since big evaporators had a lot of oil trapped. The new blends had some R290 Propane into the mix: after a retrofit, the all oil got back due to the Propane and filled up the compressors to the neck with returning oil.
Anyway, Propane never let you down on oil return and you really dont need to much to make the wonder to happen.:D Pedro

There's a lot of debate these days about what is the best sweeping agent for ultra-low freezers. Pentane was used 20 years ago but in a different application. Back then it was used in systems using CFC refrigerants like R13 or R503. Pure CFCs (although 503 was not a pure CFC)were a lot more forgiving than the HFCs are.These days it's used in applications using HFC refrigerants. It's true that pentane is hygroscopic and has to be charge by weight or volume, but POE oil is hygroscopic as well. The applications I've seen where pentane is used is with AB oil. Propane can be easier to use as it's under pressure at room temp so it can be added to the system by watching your gauge pressure to get the right amount. The whole debate comes down to whether it works well in freezers using HFC refrigerants. Ultra low freezers typically have narrow diameter cap tubes which are easy to restrict at low temps so the choice and amount of the sweeping agent becomes critical. In this new application as opposed to how it was used 20 years ago pentane works well. I have seen restriction issues these days with systems that use propane but it may not be related to the use of propane. The jury is still out.