I would like to report a possible issue with the air-conditioning temperature indications and thermal model. I can reproduce the same behaviour in both MSFS 2020 and MSFS 2024.

Test conditions

• Airport: Barcelona El Prat – LEBL
• Time: 12:00 UTC
• Simulator MSL temperature: 40 °C
• Aircraft doors: Closed
• APU: Running and available
• Bleed pressure: approximately 26 PSI
• ECON: OFF
• Recirculation fans: ON
• Both temperature selectors: COLD
• TEMP CTL channels: Automatic
• Test duration: approximately 10 minutes
• Actual behaviour

After approximately ten minutes, the three temperature indications stabilise at:

F-DK SUPPLY: 29 °C
CABIN: 22 °C
CABIN SUPPLY: 30 °C

I have attached three screenshots showing each of the three selector positions and their respective readings.

The values appear thermally inconsistent. With the cabin temperature at 22 °C, the system indicates that cabin supply air is entering at 30 °C. With the cabin temperature selector set to full COLD, this warmer supply air should not continue cooling the cabin or maintain it at 22 °C.

The flight deck selector is also set to COLD, but the indicated flight deck supply temperature remains at approximately 29 °C.

Expected behaviour:
With both temperature selectors set to COLD, the supply temperatures should react accordingly and should be lower than the zone temperatures while active cooling is taking place.

If the cabin is stabilised at 22 °C while the selected temperature is full COLD, the indicated cabin supply temperature should not remain at 30 °C unless the cabin temperature subsequently starts increasing.

Could you please check whether:

• the displayed supply temperatures are using the correct variables;
• the temperature selectors are correctly affecting each zone;
• and the cabin thermal model is properly linked to the indicated supply-air temperatures?

This behaviour is reproducible in both simulator versions under the same conditions.

Thank you.