Moisture in POE-oils vs.other installation alternatives

[hkj]

Acc.to standards the max. acceptble level for moisture in POE -oils used in heatpumps is 50ppm.There is an equillibrium in airconditioning systems between the original compounds in POE -oils and the reaction products and the water is one of them.

Has anyone a relevant idea what could be the avg. burden of H2O in the systems resulted from the mere POE-oils?
Nowadays the heat-pumps tend not to have any cleaners to collect this stuff away from the circle.

We are fuzzing over the humdity coming from the installation of Cu-pipes unless not properly vaccumed (air quantity abt. 0,5litres for 2x7,5m 1/4"+3/8"-piping).

Think of purging the piping only by for ex. BBQ-gas ( 95% propane+H2O max.200ppm acc.to a standard + some odour+methanol during winter time).I figure at least 99% of the air will be ventilated away .There will be some moisture left ,but is this a big issue compared to the existing POE-oil`s H2O burden ?

Are we facing here the "tradition" and lobbing from the "faculty" of vaccum-industri?

Are we really using our brains when demanding solely vaccuming-procedure?

[hkj]

Some background to my earlier inquiry:

Assuming Rough H20 BURDEN in a commercial system of 2,5 .. 3,5kW:

Origin H2O in system "standard"
R410a 1000g => 10 mg (max. allowed H2O 10 ppm)
POE 300g => 15 mg ( " " 50 ppm)

Purging alternatives
Propane (R290) 0,5 litres => 1/100 mg (max. allowed H2O 10 ppm,pipeline 2x7,5m)
Propane (95%) 0,5 litres => 20/100 mg (max. allowed H2O 200 ppm,pipeline 2x7,5m)
--------------------------------
AIR 0,5 litres 7,5 mg (air +15degC, 15g moisture in 1m3 of air)
(pipeline(2x7,5m)

There is the basic question left:
WHY on earth we(?) recommend solely to vaccum the installation Cu-pipelines?

If there is some moisture left in the installation pipeline,the POE-oil functions as a dryer!
The quantities of moisture after purging of for ex. propane (95%) is only
0,2mg vs.max.15mg H2O in POE-oil.



Tell me if there is something which I missed .Eventhoug the purging is not 100% complete there is a lot of H2O "dryer-capasity" left in POE-oil before facing the max. standard levels.The vaccuming itself is not 100% proof either!

I repeat my question:
What could be the avg. original moisture content (ppm) in POE-oil (prefilled in compressor )?
Does anyone know more of the chemistry of the acid esterization and decomposition activity of POE-oils during vaccuming?

[Brian_UK]

With vacuuming the 'standard refrigeration engineer' has a set of standards to work too, namely the vacuum level to achieve. He also only needs to carry his vacuum pump and Torr gauge.

With your proposed method of purging, how do you prove that the purge has been successful and the system is dry.?

[hkj]

Quote:
Brian_UK
Re: Moisture in POE-oils vs.other installation alternatives
With vacuuming the 'standard refrigeration engineer' has a set of standards to work too, namely the vacuum level to achieve. He also only needs to carry his vacuum pump and Torr gauge.

With your proposed method of purging, how do you prove that the purge has been successful and the system is dry.?

My point here is to questionize the common practices related to vaccuming of new recidental heat pumps.
If standard Cu-piping ( blanc and dry inside) available,why focuss such heavy procedure as vaccuming to installation?

It is for sure,that purging of the pipelne does not give you any "warranty" rgd. the final moisture content .
But you do not get the "warranty" either through "hasty and professional missinstalation" which is more or less frequent in the business.Is there some sense to chase after the final moisture traces by vaccuming ... it is like shooting a mosquito by heavy artillery!

Which one is the main goal in vaccuming: to get rid of moisture or .. air in the pipeline?
I figure it is nowadays the air.The moisture itself tend to eagerly be swallowed by the POE-oil (without letting it escape after POE- adaption/capture ether).Earlier,when HCFC-componds we prevailing,the moisture was
the poison no: one.

As stated before there could be a "huge" capasity left in POE-oil to clean the system against the traces of moisture even if the piping is only purged even by propane (95%).And this all still inside the standard ppm -levels!

This could be the DIY-man`s safe way not to bother "professional" skils.

I repeat my question:
What could be the avg. original moisture content (ppm) in POE-oil (prefilled in compressor )?
Does anyone know more of the chemistry of the acid esterization and decomposition activity of POE-oils during vaccuming?
------------------------------------------------------------

Sorry,my earlier "table" was screwed up and not clear enough due to RE-software.

Once again in table -form:

Assuming Rough H20 BURDEN in a commercial system of 2,5 .. 3,5kW:



Origin
Quantity
H2O burden

system "standard"




R410a

1000g

=> 10mg
max. allowed H2O 10ppm


POE
300g
=> 15 mg
max. allowed H2O 50ppm


Purging alternatives





Propane (R290)
0,5 litres
=> 1/100 mg
max. allowed H2O
10 ppm,pipeline 2x7,5m


Propane (95%)
0,5 litres
=> 20/100 mg
max. allowed H2O
200 ppm,pipeline 2x7,5m


AIR

0,5 litres
=> 7,5 mg
air +15degC, 15g moisture in 1m3 of air
(pipeline(2x7,5m)

[chillerman2006]

The poe oil does in fact absorb a lot of moisture/water

problem being 'if' not removed when the oil travels around the system

the water can freeze at the metering device to evap and cause a blockage

water in the oil also degrades its ability to lubricate

so yes we do need to remove the water content from oil

http://www.youtube.com/watch?v=Par-jcV2tPc

http://www.youtube.com/watch?gl=GB&h...&v=tlQ5gpbgilo

[hkj]

Chillerman,you do not use common sense!What does the youtube give to us?

We are not going further in this issue.

If the total tolerance for POE in this particular case is ...say ...that 15mg H2O (=absolute maximum or much less) and there is extra 0,2mg H2O ( maximum) coming from propane(95%) due purging the pipeline ,it is for sure it does not block the metering system.Note ,we are all the time on the safe side of the standard.H20 is not flooding in the installation pipes!

Even the recycled R410a (acc.to standard) could give 10mg H2O "raw material " for the blockage. Does someone claim this could cause the blockage?

Do I have to draw the conclusion the proffs(?) do not bother to rethink what they are doing.Is there anyone from the lubricant-
or compressor industri to give a comment?

What could be the avg. original moisture content (ppm) in POE-oil (prefilled in compressor )?
Does anyone know more of the chemistry of the acid esterization and decomposition activity of POE-oils during vaccuming?

I picked up these from the net:


http://www.emersonclimate.eu/literature/eCopeland/EN_C060217_AGL_ZHEVI_0.pdf

One characteristic of POE is that it is far more hygroscopic than mineral oil (Figure 9). Only brief exposure to ambient
air is needed for POE to absorb sufficient moisture to make it unacceptable for use in a refrigeration system. Since
POE retains moisture chemically it is not possible to completely remove it through the use of vacuum.
Compressors supplied by Copeland contain oil with a low moisture content, and this may rise during the system
assembling process. Therefore it is recommended that a properly sized filter-drier is installed in all POE systems. This
will maintain the moisture level in the oil to less than 50 ppm. If oil is charged into a system it is recommended to
charge systems with POE containing no more than 50 ppm moisture content. If the moisture content of the oil in a
refrigeration system reaches unacceptable high levels, corrosion and copper plating may occur.

http://www.qwik.com/qwik_article2.jsp (http://www.qwik.com/qwik_article2.jsp)

Mineral acid has always been a problem because it leads to etching of the insulation off the motor windings and subsequently to compressor burnouts. The formation is accelerated by the presence of water. In the old days, a CFC or HCFC refrigerant’s breakdown into an acid quickly led to system failure. With today’s HFC/POE systems however, rapid compressor burnout worries take a backseat to the threat of a POE oil breaking down into precipitous sludge leading to system failure. In the old days it was the refrigerant breaking down, whereas now it’s the oil breaking down. Today, both forms of acid should warrant consideration.


In general, the refrigerant and oil manufacturers have ensured that their proprietary compositions of additives are compatible with each other. However, combining these chemical additives with acid neutralizers, dyes, or leak stopping chemicals can be a recipe for disaster. Many technicians also fail to realize that water and air in a system are more of a problem with the new synthetic oils.
Acid Issues are Different
Organic acids - which are milder - were once considered to be the only acids that can be formed in HFC/POE systems, however new research has changed that opinion. Mineral acids can still be formed in HFC/POE systems. For example the 2000 ASHRAE paper by K.C. Lilje “The Impact of Chemistry on the Use of Polyol Ester Lubricants in Refrigeration,” examined the effect of various phosphorus antiwear additives on the formation of acid in HFC/POE systems and found strong mineral acids in the system. Therefore while the failure mechanism in HFC/POE systems may be sludge build-up due to precipitation from mild organic acids, these systems can also burn-out from strong mineral (inorganic) acids. In the example cited here a “conventional” mineral-acid (strong-acid) burnout would probably occur in about 40 hours of run-time for this situation. Thus, strong mineral acids and subsequent burn-outs can occur even in POE systems. The statement that HFC/POE systems don’t form dangerous mineral (inorganic) acids is technically true. The problem is that in the real world the systems contain more that just pure HFC refrigerant and pure synthetic oil. The oils can have additives that generate mineral acids when exposed to air and or water.

An understanding of POE oil basics helps explain why the presence of water in the system exacerbates the problem. POE oil is made from organic acid in an esterification reaction. When exposed to water the POE lubricant hydrolytically decomposes back into an acid. The amount of acid generated from POE hydrolysis is dependent on the amount of water available. More water causes more acid to form. Unfortunately, POE, PVE and PAG oils are very hygroscopic with saturation values of 2,500, 6,500 and 10,000 ppm water respectively, compared to only 25 ppm for mineral oil. (That is 100-times to 400-times the water!) While PVE and PAG are different than POE and not subject to hydrolysis, they are still prone to a similar oxidative degradation which also forms sludge.

This Danfoss -file occured to my eye:

http://acma.vn/admin/upload/download/Scroll%20Tech%20Compressor%20-%20Model%20ST%20(R22-R404C-R410A)-Selection%20&%20Application.pdf

Speciality: .pdf-page 9/36 (rgd.scroll R410a -pumps with oil fillings of ca. 1kg ..1,6kg)

Every compressor is dehydrated ,evacuated and charged with dry nitrogen...Max. residual moisture levels are 232mg ... ... 340mg

page 26. ...dryer required

page 28. vacuum recomendation at least 500 micron/= 0,67mbar

-----------------------------
Rgd. Danfoss ,their compressors really seem to flood before shipment ! => dryer needed due this flooding???
Vaccuum recommendation not specially challenging!!!

[chillerman2006]

Well if you want to get personnel, Chair Polisher

I will state fact - you have not got a clue what you are talking about

those video's (by very experienced members here) were ample for you to realise how wrong you are

Now dig your head out of the sand and listen

1: purging can/does leave non condensibles in a system
2: failing to vac properly leaves moisture in a system
3: ''F-Gas'' laws (EU/UK) tell us what is acceptable (NOT YOU) and purging is not.......The End

[hkj]

Hope the dust has settled down ,Mr.Chllerman.

I have to confess I am not a spokesman/lobbiest of the vac-industri.

I really would like to find the clue how wrong I might be in this topic.
I would like to "polish my ass" a while further and state:

1: purging can/does leave non condensibles in a system ...true!
2: failing to vac properly leaves moisture in a system ...true!
-Even "successul vac "leaves moisture
-There is no standard for vac-levels for small units
... you vac as well as your equipment allows!

3: ''F-Gas'' laws (EU/UK) tell us what is acceptable (NOT YOU) and purging is not.......The End
-That law deals with Fluoro-refrig.gasses .
- Purging with such one is illegal .. for sure!

-rgd. HC-gasses/N2 etc.purging ,there is no directive

-new regulations allow 300g HC -systems (residential)

When further digging the POE-dilemma,I found the exellent ,practical US-story below.This is something we all should be aware of to realize the extent of lacking sense of proportions in vaccuming :

http://www.heatinghelp.com/files/posts/2547/POE%20oil.pdf

After reading that story you may realize ,a trace of moisture in the installation piping is not our enemy.The non-condensebles and POE-oil are the ones .
Remedy for cure :Install a properly sized dryer!

In my country we say:
One can commit right things or ... commit things ... right!

Now I ask myself:
To vac or not to vac ... that`s the problem!

[chillerman2006]

1: purging can/does leave non condensibles in a system ...true!
2: failing to vac properly leaves moisture in a system ...true!
-Even "successul vac "leaves moisture
-There is no standard for vac-levels for small units
... you vac as well as your equipment allows!

3: ''F-Gas'' laws (EU/UK) tell us what is acceptable (NOT YOU) and purging is not.......The End
-That law deals with Fluoro-refrig.gasses .
- Purging with such one is illegal .. for sure!

-rgd. HC-gasses/N2 etc.purging ,there is no directive

-new regulations allow 300g HC -systems (residential)

When further digging the POE-dilemma,I found the exellent ,practical US-story below.This is something we all should be aware of to realize the extent of lacking sense of proportions in vaccuming :

http://www.heatinghelp.com/files/posts/2547/POE oil.pdf

After reading that story you may realize ,a trace of moisture in the installation piping is not our enemy.The non-condensebles and POE-oil are the ones .
Remedy for cure :Install a properly sized dryer!

In my country we say:
One can commit right things or ... commit things ... right!

Now I ask myself:
To vac or not to vac ... that`s the problem!

Hi HKJ

one of the video's I put links to are showing an ice/oil/refrigerant mix

that blocked a reclaim unit, this was pulled out of a new installation

the author of that video has set some guidelines for vaccing

they were published in a magazine 'RAC Service Engineer'

which I still do not have a copy of, but will try to make contact

and ask him for either a copy or to join this debate

setting us all on the correct road, with regard to vaccing.......

there is no guidelines for C02/N2 & Hydrocarbons

as the guidelines are based upon refrigerant release with HCFC's

I work with HC's and carry out vaccing as with any other refrigerant

the benefit of HC's is they can be run with 'mineral oil' !

Have not been given updated info on domestic HC system allowance

being upped from 150g to 300g, so can not comment

have yet to read your link, but agreed anyway that a trace of moisture

in a system is not an issue, its just poe is like a sponge to moisture

and some where along the line from manufacture to installation

the oil is being exposed to atmosphere and moisture is getting in

to the extent we would need to be fitting massive driers to systems

than we currently do to equal out the possible moisture holding content

of the volume of oil, some smaller systems we are only talking grams

but larger systems hold litres of oil

R's chillerman

[hkj]

Here below is the link of HC/300g permit to GREE.

http://www.ejarn.jp/Type_news_inside.asp?id=13719&classid=10

"In 2009, the company successfully resolved key problems standing in the way of using R290 in air conditioner applications, including controlling the amount of refrigerant charge, product safety, energy conservation, the need for a specially designed compressor, issues involving manufacturing processes, leak prevention, isolating the ignition source, and improving the safety-oriented control logic. The cooling capacity of the new product is 2,639 W and the refrigerant charge is less than 300 g, which meet the requirements of EU standards."


Rgd. the basic topic ,there could be only estimations given on the quantities of moisture originated from the purging of propane (95%) and the "adhesion" of H2O to the pores of Cu-installation tubing before the purging.

Moisture (see table before) from propane itself (0,2mg) is hardly a problem ... the question is how very well the air (together with moisture) could be pushed/diluted away from the microstructure of Cu-tubing inside surfaces by purging.

Propane is cheap.Vaccuming takes ....,say 30min.

My common sense says the purging rate will easily approach >95% of the air content => < 0,38mg H2O left
from the air volume before purging.

If a droplet of water is 50mg ... we are dealing with a quantity of <0,6mg H2O -trace in this topic.

Acc. to the POE-standard in this topic, 15mg is the "allowed " total burden of H2O in the system.
If POE-oil is already in the begining contaminated to the top of 50ppm/H2O ,then this topic is created in vain.

My simple question is,how far below the top we are ?

[monkey spanners]

Vacuum it while you are doing the wiring, cleaning up, testing the drain etc

Its not like you have to sit and watch the pump while its vacuuming.

Jon :)

[Brian_UK]

One other thought perhaps....

Assuming that you have purged the lines etc with propane, how do you the propane out of the system before you let the refrigerant out of the machine into the lines?

Or do we have to ensure that the propane will always be safe to mix with whichever refrigerant is being used?

[hkj]

One other thought perhaps....

Assuming that you have purged the lines etc with propane, how do you the propane out of the system before you let the refrigerant out of the machine into the lines?

Or do we have to ensure that the propane will always be safe to mix with whichever refrigerant is being used?

Good point ,Brian.

You do not have to worry of the HC-condensebles in the system ,if the standard-limits are not usullally exceeded.
Together with R22,R404 and R407C HC´s even are excellent partners!

Below canadian asset to this POE-topic:

http://www.rses.org/assets/journal/0110_MSAC.pdf (http://www.rses.org/assets/journal/0110_MSAC.pdf)


Depth of vacuum
Question:

I always thought I was going the extra mile pulling
down to 50 microns; yet I recently heard from factory
reps that 500 microns is correct—any deeper and
system components may get ruined. Please describe
all aspects of vacuum so this is clarified.

Answer:
500 microns has been and still is the industry standard. This
ensures that the system is dry and leak-free. Always follow the
manufacturer’s installing and operating instructions.

Pulling a system down to 50 microns will degas particles
from the compressor oil; doing this will change the makeup
and it will no longer be a good lubricating oil. If you pull a
50-micron vacuum on the piping or another component other
than the compressor with oil in it, the amount of extra time
it takes to go from 500 microns to 50 microns may give you a
warm and fuzzy feeling but the end result will probably be the
same as 500 microns held for 24 hours.

ARI 700 standard for Fluorocarbon Refrigerant states that
maximum allowable levels of contaminants are 10 ppm by
weight for water, and 1.5% by volume for air and other noncondensables

A micron level of 1,000 is <10 ppm of moisture.
Moisture will be released from MO and AB oil with a deep
vacuum. POE oil is not as forgiving, as it will hold the moisture
under a deep vacuum. So, the only way to remove moisture
is by using a filter-drier. The higher the moisture level,
the more times the filter may need to be replaced. A moisture
indicator in the liquid line after the drier will show if higherthan-
normal moisture levels are still in the system.
If you pull and hold 500 microns on a system, that system
will have <10 ppm of moisture and be leak-free. A good core
filter-drier will hold moisture and keep it from circulating through
the system.


Below the ARI-standard:

see page 19/24 for R410a ,for ex.

http://www.ahrinet.org/App_Content/ahri/files/standards%20pdfs/AHRI%20standards%20pdfs/AHRI%20700-2006%20with%20addenda%201%20and%202.pdf




All Other Volatile Impurities


% by weight max. 0,5%






Pls,note the standard serves the needs of F-gas reclamation industri/services and gives a huge "forgiving asset" to the players in terms of second-hand market of "slightly contaminated" refridge-gases .

Note, the max. quantity of non-condesebles is also named (1.5% by volume for air and other noncondensables).

You may ask,what the hell this standard is for? Normally there are no AIR-traps in the systems to collect this stuff away!
What could then be the tot. free ,"gaseus" volume in the systems;if you know that you
could calculate ,how much dry air (for ex. as a purging medium !) one could add into the system without violating the standard.


Above the lobbing stinks like conspiracy!

Rgd. Dryers vs. ARI:

Danfoss is also mixing the soup with its equipments;

http://www.danfoss.com/NR/rdonlyres/0FDC77B8-A56B-497B-A1E4-A03DF0ADEE24/0/fdarticle.pdf

"Drier selection is based on the ARI standard 710. Several expressions are used
in the selection process such as the EPD (Equilibrium Point Dryness) This
defines the lowest possible water content in a refrigerant in its liquid phase, after
it has been through a drier. The drying capacity is the quantity of water the filter
drier is able to adsorb at 24ºC and 52ºC liquid temperature. The selection is given
in Kg of refrigerant being dried out. The start and finish figures in PPM vary with
the refrigerant type."

Below the corresponding ARI-standard:

http://www.ahrinet.org/App_Content/ahri/files/standards%20pdfs/ANSI%20standards%20pdfs/ANSI.AHRI%20Standard%20710-2009%20(I-P).pdf

Page 6: Target value for max. H2O in liquid refrigerant (for ex.R410a) 50ppm !!!!!!!!!!!!

In tems of acid removal the standard is toothless:

2.4.1 Acid Removal. It is known that acid in a refrigeration system causes harmful corrosion. Many Liquid-line Driers will remove acids. However, there is no knowledge at the present time as to what concentration of various acids is allowable, nor how to test a liquid-line drier’s ability to remove these acids. Therefore, while noting its importance, no consideration of acid removal is given in this standard at this time.

[chillerman2006]

Hi hkj

the real problem we have in this industry is those sitting in offices and politicians having far too much input

without seeing for themselves the real world issues encountered on the coal face

ideal world does not exist but we still constantly recieve ideal world standards

f-gas for example is just political ball at present and does nothing for the industry

apart from give qualification to those who should be supervised

purging has always been frowned upon and you wont be changing any engineers minds in a hurry

maybe your questions would be better suited somewhere you might find support for your suggestions

R's chillerman

[hkj]

http://www.youtube.com/watch?gl=GB&h...&v=tlQ5gpbgilo

This video made me curious.
I figure out the "deep cold "cristalsl" are coming out from a dryer or filter ,maybe blown out with F-gas together with shaking the tubing?

There is bubbling between the man´s fingers when squeezing and melting the stuff.
Water does not bubble between fingers in those conditions.

The cristals look like dry silica gel (or zeolite),which may turn to sky-blue when saturated by water (dryer-case).Even then it is unbreakable between fingers!Also Al-okside possible (acid trap).Hardness unknown.

Dryer broken through shaking? I do not doubt!

Sludge/precipitation from filter .More obvious ...

Bubbles due evaporation of F-gas in the sludge-cristals.Any visible blisters afterwards in the man´s finger tips?

If the crystals are sludge,the filter is working as it should.The ones are out of the circle,not clogging the metering devise.!Eventual moisture is located in POE-oil (or dryer).

=> At the basis of the video I could only speculate about the initiator of the crystals!
Why this gadget was taken out of "production" in the first place?


The brandname of the gadget? Chinese/Japanese ???

[Grizzly]

hkj.
What do you do for a living?
I am amased you have had such a good responce.
We work to the given Best practice standards within each of our own Countries.
I am fighting the urge to be rude, but suffice to say is there a point to all this?
Other than you can copy and paste woffle?
Grizzly

[chillerman2006]

This video made me curious.
I figure out the "deep cold "cristalsl" are coming out from a dryer or filter ,maybe blown out with F-gas together with shaking the tubing?

There is bubbling between the man´s fingers when squeezing and melting the stuff.
Water does not bubble between fingers in those conditions.

The cristals look like dry silica gel (or zeolite),which may turn to sky-blue when saturated by water (dryer-case).Even then it is unbreakable between fingers!Also Al-okside possible (acid trap).Hardness unknown.

Dryer broken through shaking? I do not doubt!

Sludge/precipitation from filter .More obvious ...

Bubbles due evaporation of F-gas in the sludge-cristals.Any visible blisters afterwards in the man´s finger tips?

If the crystals are sludge,the filter is working as it should.The ones are out of the circle,not clogging the metering devise.!Eventual moisture is located in POE-oil (or dryer).

=> At the basis of the video I could only speculate about the initiator of the crystals!
Why this gadget was taken out of "production" in the first place?


The brandname of the gadget? Chinese/Japanese ???

Hi HKJ

the video shows - Water/Moisture (Solid/Ice) Refrigerant & Oil

nothing else

this was a new a/c installation with poe oil

maybe you will understand now, why we can not consider purging ?

R's chillerman

[Emmett]

hkj,
I'm not sure about your agenda, but perhaps if I keep it simple you will understand. I personally always vacumm to at least 500 microns and hold it there for at least 30 min, why? because this is what I learned in school 20 years ago, and this is what I learned from the journey man who taught me 18 years ago and I have done so with complete suscess of every installation/repair (both POE and mineral oil). I am certain that if you take my 20 years experience along with the x years of experience of every engineer using this site has personally used this method sucessfully then you would have thousands of years of experience to draw the conclusion that this is a very good method of not only removing the necessary moisture from the system, but also proving the system is tight and leak proof, why then would you want to purge?

[Fri3Oil System]

Hi,

Sometimes, the experience is based on bad habits, but we just take it as good, because, "they taught us to do that way", but that does not mean it is the best option, just the one we know.

Getting rid of moisture in a system is extremely important, specially today, with the use of POE. It is not the same for MO, and both oils should not be treated at the same level. Only a deep vaccuum won't remove all moisture, specially if there is oil inside the circuits, but then you should heat all the pipes and break the vac with N2, that will also asorb moisture...

You can pressure test a system, and "tomorrow" you can have a leak through which moisture can enter, and then, you have the problem. With MO, this problem was much smaller, but today, you have to check the acidity levels periodically, and correct the problem in case. (not talking about acid away, obviously).

In summary, are we accurate enough to leave a whole circuit below 50ppm of moisture? can anyone measure that on site? What we can do, is to check and correct problems before you have a burn out.

Regards,

Nando.

[chillerman2006]

Sometimes, the experience is based on bad habits, but we just take it as good, because, "they taught us to do that way", but that does not mean it is the best option, just the one we know.

but then you should heat all the pipes and break the vac with N2, that will also asorb moisture...


Hi Nando

''they'' taught me too that breaking a vacuum with nitrogen absorbs moisture

when in reality all it will do is lower the % of oxygen and other gases that make up the air around us

it will not contribute to the removal of moisture content in oil

am also curious, how you intend to 'heat all the pipes' ?

systems I work on will have a number of circuits which will remain running whilst you carry out the remedials on one circuit, keeping the evaporator and insulated suction line at a low temp

the only partial cure once moisture is in, is to change the oil/drier cores, run the system for a period of time and change the oil and continue doing so along with the drier core each time until compressor oil is at acceptable levels

once moisture is in a large system containing litres of oil, you can vac for a month of sundays and still not get it out

I think the answer is, dont let it get in to start with, good maintenance, checking lp trips ok

and if you have to break into the system, keep it slightly positive, and seal again quickly

I would also like to see suction line filters fitted as standard to all systems that have been opened

R's chillerman

[Fri3Oil System]

Yes, heating all piping is sometimes impossible, I didn't want to create a debate on that, sorry about it! But you have to heat as much as you can.
Anyway, if you still have oil, moisture, or water will remain below the oil and you can't get it out only with vaccuum. Firstly, you have to remove the oil, and then remove the water/moisture. I don't know how many ppm's of moisture could there be, but I've seen (water)flooded circuits apparently 100% dry with this proccess. Maybe you'd like to ask at Business Edge Ltd. about the water case at a major Bank headquarters in London Downtown a few weeks ago.

And yes, you're right, "starting from the begining", avoid air/moisture entering the circuit is the right thing.

Regards,

Nando.

[chillerman2006]

Hi Nando


Circuits flooded from the water circuit when a vessel breaks is another ball game altogether

A system in that state will actually turn out better in the end if correctly treated

Some systems have to be dissmantled and others dont dependant on the layout of tubework

You get in a specialist team who will flush the circuit for you and if needed you reasemble

Or

Use Rx11-Flush which can be used with an oiless recovery unit as in the 'RDA CareMaster type B'

and a recovery cylinders allowing vapour to be re-introduced into the system

http://www.rda-eng.com/specials.html

http://www.nucalgon.com/products/totalsystemprotect_rx11flush.htm

R's chillerman

[Fri3Oil System]

I don't see any advertising there. Maybe you know another way to extract all oil and water from a plant, but that's another discussion. You would probably still blow nitrogen, change filters and cross fingers.

Regards,

Nando.

[chillerman2006]

Hi Nando

always used to use R11 & now days as above Rx11-Flush

your procedure of blow nitrogen & cross fingers

appears to be on par with the original poster

R's chillerman

[Emmett]

Hi,

Sometimes, the experience is based on bad habits, but we just take it as good, because, "they taught us to do that way", but that does not mean it is the best option, just the one we know.

Getting rid of moisture in a system is extremely important, specially today, with the use of POE. It is not the same for MO, and both oils should not be treated at the same level. Only a deep vaccuum won't remove all moisture, specially if there is oil inside the circuits, but then you should heat all the pipes and break the vac with N2, that will also asorb moisture...

You can pressure test a system, and "tomorrow" you can have a leak through which moisture can enter, and then, you have the problem. With MO, this problem was much smaller, but today, you have to check the acidity levels periodically, and correct the problem in case. (not talking about acid away, obviously).

In summary, are we accurate enough to leave a whole circuit below 50ppm of moisture? can anyone measure that on site? What we can do, is to check and correct problems before you have a burn out.

Regards,

Nando.

I agree Nando sometimes we are taught bad habits, however any technician worth his salt will quickly figure out what works and what dosent. I also agree that just because weve been taught a certain way and it works well does not necessarily mean it is the best option, however if it is all you know then it is the best option for you isnt it.

[xxargs]

This video made me curious.
I figure out the "deep cold "cristalsl" are coming out from a dryer or filter ,maybe blown out with F-gas together with shaking the tubing?

There is bubbling between the man´s fingers when squeezing and melting the stuff.
Water does not bubble between fingers in those conditions.



I think movie show clathrate hydrate make from water and refrigerant together and make 'ice' together in some situation and stay in 'ice' form up to pretty high, near room temperature before melting back to water and refrigerant again. Of course this can make big trouble in refrigeration equipment and plug capillaries, filters and TXV in some situation if system have to wet refrigerant circulating inside.

In nature we have enormous amount of methane clathrate hydrate as 'methane ice' deep on sea in many places and possible usable in future as energy source if we can mine this _or_ make us in very big trouble of whole world if this melting and bubble up deep from sea as consequences of global warming...

ASHRAE RP-923 (cannot find this document longer on google) cover this problem and for short conclusion of long report they recommend:

"
Maximum Amount of Water Tolerable in Systems at -40°F (-40°C)
Based on Clathrate Formation:

Refrigerant Water (ppm)
R-134a 30
R-32 10
R-143a 15
R-125 200
R-152a 150
R410A 15
R407C 15
R507A 40
R404A 40
"

and conclude is very good idea to try to stay with recommendation of hold max 10 ppm water content in refrigerant...

Report have also picture evidence above clathrate Formation with refrigerant is stable and not melted on +50 degree F or +10 degree C.

[hkj]

Exxellent conclutions ,xxargs.

I hope You did not have to polish your ass into blisters due to the researsch!


I think movie show clathrate hydrate make from water and refrigerant together and make 'ice' together in some situation and stay in 'ice' form up to pretty high, near room temperature before melting back to water and refrigerant again.

Maximum Amount of Water Tolerable in Systems at -40°F (-40°C)
Based on Clathrate Formation:

Refrigerant Water (ppm)
R-134a 30
R-32 10
R-143a 15
R-125 200
R-152a 150
R410A 15
R407C 15
R507A 40
R404A 40
"

and conclude is very good idea to try to stay with recommendation of hold max 10 ppm water content in refrigerant...

Report have also picture evidence above clathrate Formation with refrigerant is stable and not melted on +50 degree F or +10 degree C.

I wonder whether this phenomina could be used as a "cleaner/dryer " of the system ,if the clathrates are somewhat stable in the system conditions ....

"recommendation of hold max 10 ppm water content in refrigerant..."
This is propably set by the reclamation industry of F-gases to ensure the second-hand market
for the rechargable gases.Totally ok despite of H20-cumulation -risk,if dryers not rechanged simultaneusly as well.

________________---

But back to the basic topic.

The moisture content of POE (<30ppm) seems to be the industry limit just for fully-halogenated ,fluorinated and chlorinated hydrocarbons

Quote:

http://www.fuchs-europe.de/uploads/media/RENISO_Refrigeration_Oils_2010-2011.pdf

Refrigeration oils for partly and fully-halogenatedfluorinated and chlorinated hydrocarbons (CFC,HCFC) – as a rule, mineral oils and alkyl benzene(in some cases ester oils also possible).Mostly, highly-refined, naphthenic mineral oilsand specially-treated alkyl benzene (alkylates) areused. The water content of fresh KC oils shouldbe < 30 ppm. If the water content is higher, thereis a danger of undesirable reactions with the refrigerantwhich can lead to the decomposition ofthe oil-refrigerant mixture.


RGd. HFC´s , the limit is ... suprise,suprise ... 100ppm!


Refrigeration oils for partly and fully-fluorinatedhydrocarbons (HFC, FC) – as a rule, polyol esters(POE) or polyalkylene glycol (PAG). The refrigerationoils described in group KD are polar productswith pronounced hygroscopic characteristics.For fresh polyol esters (POE), the water contentshould not exceed 100 ppm. Polyalkylene glycol(PAG) are often used in aircon systems. Their maximumfresh-oil water content should not exceed350 ppm.


and further

http://hvac-talk.com/vbb/showthread.php?t=150330 (http://hvac-talk.com/vbb/showthread.php?t=150330)

"Quote:

50 ppm moisture with POE is about as low as you should expect for virgin POE in drums. In bulk 6000 gallon trailers delivered direct from the POE manufacturer, it normally runs about 30 ppm. When it is put into a system the level of moisture usually increases. 100 ppm is not out of the norm.

The moisture in the POE will redistribute itself into the refrigerant very quickly once the system is running. If there are filter driers in the system, the desiccant will grab the moisture from the refrigerant. Circulating moisture levels below 120 ppm are not a concern, unless you know the discharge or condensing temperatures run very hot where the moisture could damage the POE. If the moisture is doing any damage to the POE, you can track it by the increase in TAN (acidity). At room temperature, the chemical reaction between POE and moisture is extremely slow. Unless something very strange has happened, the TAN on the POE in your machine should be very low, and the POE is just fine. If your oil analysis shows the TAN is below 0.05 mg/g KOH, then nothing bad has happened to the virgin POE because of moisture.

If you want lower moisture levels in the system after it is started up, change out the filter driers after the refrigerant dehydrates the POE and the drier dehydrates the refrigerant. This will prevent any ice problems in the expansion device if the temperatures go below minus 100 F. ;- /=-38C)

I personally think changing out virgin POE because it is slightly wet is a waste when you could easily just change out the filter driers after the unit starts up.

Rob Yost
National Refrigerants "
------------------------------------

Against the above two versions ,our "moisture window-limits " in R410a -systems are suddenly dubbled from 50ppm =>100ppm of H20 in POE-oil.


Now there is the question existing:

"HOW VERY WELL THE MINI_SPLIT INDUSTRY (=using no dryers) IS ABLE TO PROTECT THEIR SYSTEMS AGAINST POE_OIL CONTAMINATION THROUGH H2O IN THEIR PRODUCTION LINES?

Probably we will never get the answer!