S-Prihadi

Hi Gang,

I do not have such label on my car, it is not mandated by law.

I have looked at all reputable Hella/Behr and Nissen and others, their table shows R134a at 590 grams, for W212 sedan.
I want to know if that is the same as what USA cars mandated label is showing ?

I want to do some checks on my HVAC as part of preventive maintenance and data gathering and need to make sure I have the correct data.
I want to find :
01 - Shop with R134a gas analyzer to see how many % are air and if any cross contamination at all.
02 - Shop with proper machine, because being a variable displacement compressor our W212 uses, pressure chart does not apply. It has to be weight of R134a and I need to make sure shop
can evacuate my system down to 200-300 microns ( very deep vacuum ) read at the opposite end of the pipe and not at the vacuum pump of the machine only and refill back to get the assumed 590 grams to 1 gram accuracy.



I do not have issue with my HVAC, it is just now 8 years old and I am itchy to know


Model Label as per on my compressor and this seems the default global model W212 uses.



Oil capacity and spec, as per Denso







Great images of the compressor from eBay seller. Brand new. Same P/N.
https://www.ebay.com/itm/313125123621



Thanks so much for the coming R134a label photo..

juststeve

A 2012 wagon for comparison W212.274

chassis

R134a. What is your vehicle designation 212.xxx?


10g, not 1g, is the fill weight tolerance.

S-Prihadi

Thank you thank you guys
Dang, I must be blind, I scrolled too fast on the WIS and only saw oil capacity and not the r134a ha ha ha.
I am on W212.065

So the table from Nissen is good for my car, but no data on 212.274 AMG and the WIS and 212.274 AMG Label is spot on .....awesome !!



Again thank you .....

kajtek1

In last years the refrigerant charges are listed by weight, but for decades I charge by pressure just fine.
The trick with variable output compressors is to force them to max output to read the pressure, but than the system are pretty flexible. I had the system working on single can (12 oz = 360g), although not very efficient, but that was on older car who had 1kg refrigerant capacity.
My W212 says 0.59kg

S-Prihadi

K,

Thanks for the 590 grams confirmation.

We have to use a variable compressor trigger kit if we want to manually control the compressor. There are a few on the market.
I do not know if that will upset the AC computer module or not, but I suspect it will because the AC computer module will loose its connection to the compressor and will
declare open circuit.

Lately I been finding great HVAC information from industrial people who also does work on cars.
Albeit I am not into any refrigerant pressure enthalphy chart, the information of how dryness ( and cleanliness) matter so much on HVAC system reminds me a lot
on my own dive compressor 101 and its air fill system humidity sensor requirement and an old model ( 1990s) oil filled dive computer training seminar I attended.
There is so much similiarity due to the unique gas behaviour and I just realized how unique r134a is compared to regular air.

Left Coast Geek

2016 US model E350 4matic wagon, 212.288

kajtek1

I grew up in Poland and we never had humidity sensor on our scuba compressor. But I was rebuilding engines and mounting the wheels without torque wrench as well.
We did have huge charcoal and other filters though.
When I learned mechanics in Poland, nobody had AC in the country, so moving to California I had to self-learn the trade in a hurry. Thermodynamics classes helped a bit, but freon 30 years ago was dirt cheap, so nobody worry about small leaks.
Now I don't like to force systems to anything unusual. Meaning when you can force the compressor to max by setting the temp to LOW, or using scanners, real life can always surprise you after.
So living in warm climates it doesn't take long to wait for sunny day and parking the car exposed will easy give you 100F/40C inside. That even with very good compressor gives you several minutes of AC going to MAX on its own, so you can play with adjusting the pressure.
Main principal is to never drop low pressure below 30psi or 2 bars.
High limit switch is in high 200's of psi, but as long as you get 200 psi the system is going to work.
Overcharging is worse than undercharging, so go slowly and have fun.

S-Prihadi

Yes, will keep in mind on your advice K on the pressure thingy. Thanks

S-Prihadi

Thank you....

Senecat

Just dump the charge into the atmosphere while giving a middle finger to the EPA, pull the system down with a cheap amazon pump for a few minutes, and throw spec weight 134a in and call it a day.

S-Prihadi

Naughty boy !!! But that is what we do in Indonesia hahaha, there is no such regulation like EPA in USA

S-Prihadi

MB does show reccomended equipment if for y1234yf refrigerant, one of the model and brand is available in my country. The TEXA Konfort 760R or 780R Bi-GAS.
Fortunately my car still uses R134a and reccomendation is only SAE J2788 compliant equipment.

Texa Konfort 760R is available and before Covid, it was purchased by a car HVAC shop. So happened the local Rep of Texa is also the Autel Rep, same company.
So I got first hand information.

However, I am kinda pissed that the 760R purchased does not have the optional refrigerant identfier , see : https://konfort770s.texa.com/ only US$2K can get it.
If I were to be a car HVAC shop owner, I would buy a better refrigerant analyzer, like this one : https://www.mybacharach.com/product/...rant-analyzer/
Its like US$3-4K I read. Fake refrigerant is abundant and poor assembly and/or poor vacuuming procedure ( or weak vacuum pump ) can introduce normal air and that is contamination too.

I been watching this experienced HVAC dude, who does industrial and autotomotive HVAC and I like his informative video and his working attitude. He is a 3rd generation HVAC family.
https://www.youtube.com/user/coldfinger459sub0

I been watching this guy too and already watched to the number 40ish videos on below's playlist
https://www.youtube.com/playlist?lis...oESxNbzHQJ-TIq

I find HVAC interesting, the r134a Pressure-Enthalphy chart is not what interested me, the similarity of cleanliness and dryness to my dive compressor air-filling procedure is the one tickling my fancy.
HVAC is more complicated though, because r134a is unique.
I am accustomed to think hard about regular air we breath (21% oxygen ) , nitrogen narcotic effect at depth and oxygen toxicity at depth and how dive compressor get damaged by
enriched oxygen content ( Nitrox diving, 32 - 36% oxygen encriched air ), but never about refrigerant.

The difference being, HVAC people do drying of their system using vacuum.
Dive compressor, we dry and clean the air we pump into our scuba tank using 13x molecular sieve (dessicant which can go to -70C or -94F dewpoint / dryness )
and activated carbon ( most bad stuff remover ) and hopcalite catalyst ( carbon monoxide converter to C02 )

Drying and cleanliness is so important for both of these industries.
The r134a boiling temperature at 1 ATM is -26.1C or -14.9F , so in term of suitable dryness of the system, I would want no "wetter" than -50C or -58F dewpoint or 24PPM ( weight basis ) in my system.
https://www.asge-online.com/pdf/ASGEpg185.pdf
In RH%, the dryness discussed would be 0.157% at 21.1C or 70F

Now that I find similiarity between my beloved dive air purification 101 to HVAC system, I totally understand why the HVAC hard core will want to vacuum down to
300 microns ( or 0.4 millibar ). As a reference, our 1 ATM or 14.69 psi atmosphere at sea level is 760,000 microns /mTorr

But I still can not find anyone in HVAC ( youtube) using combination of vacuum micron gauge and ultra low moisture meter to verify the dryness result of the deep vacuum.
It will be interesting to see, because drying a copper pipe to drier than -50C dewpoint is a bi-etch, copper is a bit WET material. Aluminum and stainless steel are "drier" material. Hose is super WET material, that is given.
I use this moisture meter for my dive air purification system, the generation 1 : https://www.shawmeters.com/product/model-superdew-3/
Cost me US$3K ish this bloodey sensor, but it brought me knowledge worthwhile its cost.

I shall update when I am done inspecting my HVAC with the Texa 760R.
Too bad the 760R digital vacuum gauge is locked to 1 miilibar only or 750 microns , but its dual stages vacuum pump can do down to like 0.4 millibar or 300 microns/mTorr
Maybe I should buy this first from USA before I visit the HVAC workshop : https://www.fieldpiece.com/product/m...-vacuum-gauge/
US$300 it will land in Jakarta tax included, but I must first buy special fitting to use it on our W212.
Our W212 uses the special R134a quick coupler like this one : That Yellow Jacket QC with male connector to connect to the Fieldpiece vacuum gauge female connector at HP port, and let the Texa 760R evacuate/vacuum via LP port only.



So, this is where the HP port 16mm measurement comes from...aha





I thought the internal female thread was for some sort of fitting, I think it is only to hold the black plastic cap which uses that thread.
Damn, I am HVAC fitting stupid.




I still have my thermocouples installed on the suction line near compressor and at the condensor output, from previous itchy hand experiment.
So, I can check my evap & condensor saturation pressure/temperature when the Texa 760R gives me the gauge pressure values. Double fun. The Autel or Xentry can also read condensor's HP pressure gauge value.
This way I can get my superheat and subcooling values .... not bad.

Yellow tape with red label no 2 is the suction at compressor

Above : No 3 white label is for reading engine bay ambient temperature.








Yellow tape label no 1 is the condensor output.



I have another sensor also reading suction, but at a less hot location. No 4 white label.




I insulated my pipes already back in May 2021, so I decided to leave those 4 sensors there for future use.





Since no refrigerant recycling center exist nor any laws forbiding it being discharged to atmosphere in Indonesia....... also the said 760R not having the optional refrigerant identfier ,
which such identifier sensor is useless too because most customers choose to re-new their r134a anyway ........ so safest bet is to renew my r134a. Vacuum super deep and use new r134a.
I really want to know how clean or what minute regular air is in my system actually....but just too bad.

S-Prihadi

So my itchy hand decided to buy the Fieldpiece vacuum micron gauge & the Yellow Jacket r134a quick coupler HP side.
Since both are shipped out of Amazon USA, it is cheaper by shipping, import duty is a bit cheaper too because duty/tax calculation is based on CIF ( Cost + Insurance + Freight ) value.
So US$360 only for both items, duty included and landed. Will arrrive June 28 to July 8th approx.

This HVAC thingy is getting interesting.
I want to share 2 information which is a good to know as a DIY-er, be it we will be the one doing the HVAC job, or when we assign a HVAC shop to do it.

Information 1
Denso oil for our vaiable displacement compressor is the ND-Oil 8 as explained earlier.
What I did not know is that this PAG 46 ( PAG = polyalkylene glycol) and the 46 is vicosity if from Denso genuine is of DOUBLE END CAPPED type.
https://www.denso-technic.com/images...2-part2-en.pdf
Dang, it sounds like a plumbing stuff, ha ha ha ha.

Below is the most important information pertaining to the oil properties.


Chemistry is always facinating and I hate it . For the chemistry aficionado, enjoy the tech papers on the Double End Capped
https://docs.lib.purdue.edu/cgi/view...0&context=icec
https://www.waeco.com/en/de/news/why...ainst-moisture


Since moisture in oil as bad stuff is not new to me, I know how important ultra dry oil is and technically HVAC oil and refrigerant system is enclosed and not exposed to the atmosphere,
I do not need a degree in chemistry is so happy to see Texa 760R special ultra-dry oil bottle.

The Texa 760R has special oil bottle which goes thru a vacuum process, to remove water vapor in oil.
Go down to : REFILLABLE HERMETICALLY SEALED OIL BOTTLES
https://konfortvas.texa.com/



Above image is from the Indonesian rep for Texa, their local language assisted user manual





Water moisture in oil, removal using vacuum pump.

You Tube

Above utube is the same care and reason for my oldie 1990s dive computer battery change where we need to replace its oil too. Oil filled Uwatec (now is Scubapro) dive computer.
Vacuuming the oil is a must. One is moisture removal and 2nd is to make all micro bubbles go away, thus no air bubble in oil to distort the LCD image display.

In 2013 I was at Uwatec/Scubapro Hong Kong repair facility, the round thingy is the oil bath vacuum chamber and many dive computers inside it.




Information 2
Non condensable gas ( NCG) in HVAC system.
https://hvacrschool.com/non-nonconde...20and%20oxygen.
So, that is what they call even regular air in the system as. Our normal breathing air is 21% oxygen, 78% nitrogen, 0.4% C02 and plus some others.

The Texa 760R system can remove this Non condensable gas ( NCG) for procedure where your r134a will be pumped back to your car HVAC system.
Me will take the easiest approach, use virgin r134a. I don't know how the machine can remove those NCG, but inside it is kinda complex with heater yada yada. Chemistry !!!!





So, non condensable gas is not to be confused with Refrigerant Contamination. Learning everyday ............
Below is contaminated refrigerant


Poor Maersk shipping line, they got whacked big time from contaminated refrigerant 3 Kaboom !!!! , I would say this is money matters by naughty vendors.
https://ozone.unep.org/system/files/...P_May_2012.pdf


This is indeed getting very interesting.
Imagine how sloppy/wrong/bad HVAC workshop can be and we won't even know if they are sloppy, if we do not actually understand the level of care and detail for a true proper HVAC job to be carried out.


That's all for now. Will update when I pick up more know-how.