Seems like the galley air cooling system is designed for cooling the equipment and food in the galley, not the general air supply for the passengers.

https://aviateai.com/efficient-galley-cooling-system-optimiz...

Maybe the refrigeration is shared with the galley (food storage), and/or is only needed when the plane is on the ground?

Or just… computer controlled air vents?

At altitude you can reject heat straight to the aircraft skin. Some designs run an internal heat sink on the ground and during climb, watch altitude, and only switch on the skin-exchanger coolant pump once outside is cold enough to cool the loop for free.

The reason it stays a refrigeration unit and not just vents is the ground case. Gate on a hot day, doors open, no ram air, warm soak: that's the worst case, and where the compressor has to work. One published point-of-use chiller design specs roughly double the load on the ground vs in cruise (order of 700 W vs 300 to 400 W per unit). So the vapor cycle is sized for the ground, and most of a 20 hour flight is spent in the regime where you barely need it.

And these aren't fridge boxes at each cart. It's a central vapor-cycle chiller cooling a glycol/water loop piped to air chillers at the galleys; the carts get chilled air. The heat comes off the condenser and goes to ram air, a skin exchanger, the cargo hold, or back into the ECS, depending on the aircraft. Which one the new ULR units use, Airbus hasn't said. For a 22 hour flight the interesting number isn't peak capacity, it's efficiency and weight in cruise, which is probably what "lighter and more efficient for very long flights" is pointing at.