A320 ventilation skin temperature threshold
 

Hello

I am very confused with logic Airbus has provided for ventilation- open configuration and closed configuration based on the skin air temperature

FCOM mentions
ON GROUND OPEN CONFIGURATION is when:
Skin temperature is above the on ground threshold

• 12Degree C and increasing
• 9 Degree C and decreasing

QUESTION 1 : What happens if the temperature is at 10 degree C or 11 degree C and increasing ??

ON GROUND CLOSED CONFIGURATION is when:
Skin temperature is beneath the on ground threshold

• 12 degree C and increasing
• 9 Degree C and decreasing

QUESTION 2: What happens if the temperature is at 10 degree C or 11 degree C and decreasing ??


QUESTION 3: Is there any other way to understand this temperature logic in a simple way ??


QUESTION 4: In a closed configuration the ventilation air goes to cargo underfloor through the SKIN EXCH INLET BYPASS VALVE . Where does this air go from here (from the cargo underfloor) . Does go out of the aircraft through the outflow valve from here ?

QUESTION 5: Why is it called a SKIN EXCH INLET BY PASS VALVE, when the ventilated air is actually go out of the ventilation duct to cargo underfloor,. Should it be not called an OUTLET valve?

QUESTION 6: In a closed configuration the AVIONIC BAY air is taken in the ventilation duct through the SKIN EXCH OUTLET BYPASS VALVE. I though the avionics bay air will be warm , if that's true why is warm air being recirculated to cool avionics equipment in a closed configuration ?

QUESTION 7: If air is coming in the ventilation duct from SKIN EXCH OUTLET BY PASS VALVE , should it be not called an inlet valve?


Please help me with my confusion
Appreciate your help

Thank you
Regards
OWL

Q1 and Q2.
A. It stays in whatever position it was last moved to. This is to stop it continually opening and closing if the threshold was a single temp. EG 10°C.

Very confusing system. You’ll land in the Caribbean and find it in the closed configuration.

I think that is to prevent warm (moist) air getting in and leading to condensation on the cold avionics.