DataLog Air Conditioner

Hello everyone,

Given the current temperatures, it seems my air conditioning system is running at its performance limit, even though it was recently refilled and there are no apparent issues with the readings.

I would therefore be interested in seeing a data log for comparison.

-> Outside temperature > 30°C
-> Controlling the N280 control valve.
-> Vaporization temperature.
-> Controlling the fresh air ventilation fan.
-> And of course, the information about what temperature was set.

It would be great if someone could send me something like that as a comparison.

Regards,
Sure, here is the translation of the text from German to English:

"Dirk"

Is there anyone out there who ever logs the climate data? Martin is actually a master of data logs:-)h.

Yes, later .

Hello Dirk,

Unfortunately, it's gotten so late today that the outside temperature has only dropped to 25.5-26.5°C. The car was parked for a short time with a hot engine, and then it was driven away.
Set indoor temperature: 21.5°C. Evaporator temperature: approximately 6°C.
The log is from an Audi A3, approximately 5 years old. No work has been done on the air conditioning system, except for replacing the activated carbon filter.

Best regards, Rainer.
Edit: I just noticed that the speed of the fresh air blower is missing... it was at about 1/3 of its maximum value.

Thank you for logging, Rainer!

It would be interesting to essentially perform a "cold start" of the vehicle at outside temperatures above 30°C, and then record a longer log showing how low and how quickly the evaporator temperature drops, and at what power level.
Very happy to pick it up from the A3 again:-).

Sure, here's the translation:

"By the way: How would you subjectively rate the cooling performance in the A3?"

Hi,

Unfortunately, there's no log data, but I still have an empirical value from the G IV, where I often observed the vaporization temperature:

Even with an outside temperature of 35°C, the evaporator temperature quickly rose to 2.5-3 degrees within 10 minutes and remained there. The setpoint was 22°C. Cold start followed by... Highway driving: 90-130 km/h.

Quote:

Is there anyone who ever logs data on the climate? Martin is actually a master of data logging.

Martin is also a "master of going to France" .

Thank you for the additional logs!

I find it interesting that in Martin's logs, the temperature at the evaporator drops to below 5°C within 120 seconds. For me, it takes at least 460 seconds (though this is under 33.5°C and in direct sunlight). The minimum temperature afterwards is approximately 2°C. The compressor remains at its maximum operating level throughout the entire duration.

Hi,

Quote:

By the way: How would you subjectively rate the cooling performance in the A3?

At 35°C, it could be better, but overall, it's okay. Purely subjectively, the target temperature is unlikely to be reached with those outdoor temperatures; today I realized how cold 18°C can actually be...

Best regards, Rainer.

Okay. I see it the same way.
In the parts system at the auto parts store, I saw that there's a different compressor available for use in hot climates. The fresh air blower is always the same. Does anyone know the difference?

Are all compressors/control valves from all manufacturers powered by the same type of current? Is there a variant encoding?

Hello everyone,

Summer is coming, and I'd like to revisit this topic.

Does anyone happen to have an overview of how the adaptation channels (Adaptmap) are configured for an A3 in a hot climate?

I'm still unsure about the difference between the Kimakompressors designed for hot climates and those intended for our region. Does anyone happen to know the Sanden model number for a US A3 compressor?

Thank you & (sunny) regards.

EDIT:
I just did some research. All the components used in the A3 (blower, compressor + control valve, expansion valve + evaporator) are standard parts, also used in much larger vehicles like the Passat and similar models. The evaporator and expansion valve are even used in the Sharan/Alhambra. Therefore, all these parts should be readily available, even for the small interior of the A3. Despite this, the compressor is almost always running at full power.

EDIT 2:
@Martin: Your Passat is supplying more than 800mA to the control valve. That's strange. Rainer's and my A3 only reach a maximum of 700mA. What is the part number/manufacturer of the compressor in the Passat? Can you identify it? Also, who actually determines the maximum control current? Shouldn't it be coming from the climate control unit? That's where the control valve is connected, at least.

I found a compressor in another forum that's installed in a 1.9 TDI Golf V. The current draw is 830mA (!). The same compressor is available for the V6 gasoline engine in the A3. I assume it has the same 630mA current draw as Rainer's and mine, since there's only one climate control variant.

I'm increasingly suspecting that 630mA might simply be too low a current to fully utilize the compressor. I might try externally powering it and see what effect that has on the vaporizing temperature.

Hello!
While the topic is somewhat old, the problem still persists. I would like to see more action taken on climate change. The car was standing in the midday sun, and it took almost 20 minutes to reach the set temperature of approximately 21 degrees Celsius.

Therefore, I externally powered the control valve under absolutely identical conditions. The current draw at 12V is approximately 1A. You can hear a distinct "click" when the valve reaches its maximum position. There is absolutely no change in the evaporator temperature. Therefore, I assume that the current of 700mA is sufficient to fully load the compressor.

If you have any other ideas, please share them!

Regards,
Brezelmann01

Hi,

I've had some hot days here recently, but I can't complain about the air conditioning. Do both fans run when the AC is turned on? The bumper wasn't even repaired, and they forgot to close the openings?

Best regards, Rainer.

Yes, both fans are running. The fresh air intake is completely unrestricted as well.

EDIT: How exactly would the lack of cooling from the condenser manifest itself? Does the high pressure simply increase, or does the cooling capacity also decrease immediately? The HD (high-definition) pressure remains relatively constant, typically between 13 and 16 bar.

It would be interesting to compare it with a similarly equipped A3. It's possible that there isn't a defect, but rather that the system's performance isn't designed to be any stronger.

BTW: Tinted windows starting from the B-pillar can also provide additional support.

Hello everyone!

brezelmann01 wrote:

... how exactly would the lack of cooling from the condenser manifest itself? Does only the high pressure increase, or does the cooling capacity also decrease immediately? HD is consistently between 13 and 16 bar.

@Brezl: The system pressure is increasing, and the cooling performance is decreasing. Before the system reaches a critical pressure, a high-pressure pressure switch will shut off the compressor.
16 bar seems a bit high to me.

The best approach here would be to simply connect a "pressure gauge" to the system and check the pressures - both low pressure (LP) and high pressure (HP) - simultaneously.
It's also possible that your dryer is clogged, which would reduce its cooling efficiency. This would be noticeable by a significant amount of condensation.

Best regards from Passau!