S-Prihadi

Something I must add.
I can't see radiator fan speed, even in actuation mode while doing the HVAC test. The Xentry actuation page explained why.
I did not proceed with the activation test for sure, I was hoping before actuation it will show at least 10% duty , which is OFF. 90% duty is 100% full power.

juanmor40

If I recall correctly, the Fan actuation entry is under M4/7 (Engine module). I have used it before (W211, W212, and W166), and you can make the car sound like an airplane.

S-Prihadi

Yes , but the HVAC N22/7 also has the same actuation page as u can see.
Yep, sound like an airplane indeed

S-Prihadi

Juan,

As promised.
Here is the pressure data for LP-Suction and HP-Liquid line.

Cooling fan at 10% duty cycle = OFF , Maximum is 90% duty cycle.




































Dugghh !!!!!!!



I have to use the Xentry Passsthru, because that laptop has the screen recorder I installed.
Xentry-Ninja I do not want to install any other software for stability and compatibility reason.

Attached is Denso tech material for exact family/series of my compressor, 6SEU16C. But maybe the control valve operating profile is different to the Toyota which the document is based on Toyota.
My compressor ID based on Denso is DCP17165.
Now I know why Amperage is used to show compressor duty cycle in Xentry, because it is true Amperage is what the Denso is using and not duty cycle per se.







Happy reading............

S-Prihadi

I would like to update ;

For those relying on the refrigerant pressure information coming out of the car/Xentry, please be informed that it is using an absolute scale and not gauge scale. Meaning it is higher by 14.7 psi if one is at sea level, when comparing
to another gauge used for HVAC manifold which is gauge pressure and not absolute pressure.





I think MB decided to use absolute pressure sensor is because refrigerant P-h chart or enthalpy chart is using absolute pressure.
If you want to learn of P-h chart, ready here : http://www.rses.org/assets/serviceap...ual/620-28.pdf
Simply put, no HVAC design can work without using P-h chart....PERIOD.

The P-T chart for refrigerant is using gauge pressure and not absolute, this is because HVAC techy uses that on the field and that is easier for them to relate to the gauge pressure they are using
from their pressure gauges. My Fieldpiece JL3PR wireless pressure gauges used for this test are also in psig.

P-T chart is below :





I been going to HVAC night school...so to speak .. LOL

S-Prihadi

I think my N70b1 temperature sensor will soon go bad .... or is it my Xentry passthru went banana after it Lost-COM to the N22/7 HVAC module ?
Communication re-established at video minute 20:45



See what happened even at video minutes 22:20 or 90 seconds later, the N70b1 is still reading 2.5C Duggghh!!!!



I now have more doubt now with Xentry Passthru for its update speed causing data error or super laggy or whatever.
I need to test again with Xentry-Ninja and compare.
I can now record the Xentry-Ninja laptop screen output via HDMI, no need software, today I simply bought a low cost HDMI video signal recorder capable of 1080p 60FPS .... ha ha ha, only US$100 and has its own baby LCD screen.
I got a semi-professional HDMI recorder already from Atomos, The Ninja 2 it is called, back in 2014 but its data bit is insane because its recording format is for professional and I won't use it for Xentry works.

Xentry own logging/graphing is limited, like 120 seconds only albeit the data is super fast at 7.43Hz. 120 seconds is too short. Need at least 1 hour capable and visually 1Hz is good enough.

S-Prihadi

I was looking at the P-H enthalpy chart for r134a.
That chart tell us how much heat energy can r134a remove from the air based on an "X" HVAC system performance, which is our car in this case.
Since we all know cold does not exist per se, more heat removed is what makes cold.
Same as vacuum, vacuum does no exist per se, it is actually the absence of atmospheric air.

In my mind desert must be hot, temperature wise, well it is, but that is not the full story of how HVAC will perform in the desert, temperature information alone is not enough, its far from enough.
The enthalpy chart now starting to make sense. It is a measure of heat energy actually.

"Enthalpy is defined as the amount of internal energy within a system combined with the product of its pressure and volume. When dealing with the term in the HVAC industry, we usually assume that the process is at a constant pressure and, as such, the change in enthalpy is equal to the heat absorbed or released."
Source : https://www.computrols.com/enthalpy-...0or%20released.
For chemistry smart ones : https://chem.libretexts.org/Bookshel...tials/Enthalpy

So, I have to ask myself, if this so called heat energy in the air is what needed to be removed/reduced by HVAC system to make my air less hot aka colder, what are the actual constituents of this heat energy I need to know ?
How is a description of my HVAC system on a similar W212 is not cool enough be understood by someone from a different climate zone, in a way they can relate ?
I need to measure the heat energy of the air in my city and the air in your city, and we can compare a 95-100% similar HVAC system performance between our W212, simply because the HVAC duty is to
remove that heat energy from our cabin air using an EVAP and dump it outside using the condenser.


This is my city ambient heat energy or enthalpy. 96,940 joule per KG or dry air or 41.68 BTU/per pound of dry air in imperial speak at hottest month , April.








This is Miami hottest month, August. 82,063 J/kg dry air or 35.28 BTU/lbs of dry air









This is Las Vegas, in July. Vegas is 610 meters above sea-level. What seems scary hot temperature of 97.3F or 36.3C in July from HVAC system work load perspective is a piece of cake.
Only 59,276 J/Kg dry air or 25.48 BTU/Lbs of dry air heat energy....











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SUMMARY




Holy crap, water moisture has so much energy and is the most evil nemesis for me.
I never ventured that far thinking about water moisture can be so detrimental.



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I would like to update on the intended 120C capable , 12V coolant solenoid valve, it is so BIG !!!! So heavy, yes robust but....... too big.