>>1071566It's probably mostly circulation related or the unit simply isn't running at full cooling capacity. The AU726 is meant to run 120 m^3/min through the main cooling system, with linedeliers just being extra airflow. Usually what happens is they have thresholds above the setpoint where the unit increases speed of the compressors or powers more of them on and it could be unusually high in the particular lineage
The newer trains are meant to also take into account the weight on the bellows to adjust the aircon output
As for platforms, a lot of stations are already cooled even without doors. It would massively increase efficiency, but most stations already have an overkill but underutilised system installed. The Sobu Line platforms at Tokyo Station come to mind. Installed capacity is something like 9060 kW but they only operate at 1/4~1/3 of that to maintain 28°C and a still nasty high humidity (there's a JR East paper on it)
And a lot of Tokyo Metro stations have some sort of installation. There's the ceiling cassette type that can be cold water or refrigerant cooled, the water cooled Daikin Mifujirator style packages (which are pretty good and they go up to ~56 kW and you can just stand in front of them to take in the breeze) and and some newer stations have ducted
All of the misery probably comes from the underutilisation part. It's like seeing all the overkill VRF installations in public and office places and yet the room is hot because someone is penny pinching or wants to appease the ladies
