A passenger train of the Seoul Metro Line No.1 / Korea Times file
As summer temperatures begin to climb, the battle over the thermostat is moving underground.
Inside the packed cars of the Seoul subway, transit officials are facing a paradox: hundreds of thousands of commuters demanding freezing air, while thousands of others beg for relief from the chill.
According to data released Friday by Seoul Metro, the municipal operator handled over 1.01 million rider complaints last year. A staggering 78.4 percent — nearly 790,000 cases — were related to train temperatures, with the vast majority of riders protesting that cars were too hot.
Yet, as customer service centers brace for the seasonal surge, transit officials have a message for frustrated commuters: The conductors cannot help you.
Under environmental regulations mandated by the Ministry of Climate, Energy and Environment, train temperatures are controlled by an automated climate control system programmed to maintain a baseline of 24 to 27 degrees Celsius in the summer.
"Riders often believe train operators can manually crank up the air conditioning on a whim," said Han Ji-hoon, an official at Seoul Metro’s train operations division. "But the system is entirely automated. We cannot simply lower it to 18 degrees Celsius because a specific car feels crowded."
The issue peaks during rush hour, when high passenger density spikes localized humidity. During morning and evening commutes, complaints that cars feel too warm account for 72.8 percent of the daily total. Over half of all "too cold" complaints are logged during these exact same hours, driven by lower-density cars and individual sensitivity to cold.
To mitigate the administrative burden — which officials say distracts from reporting medical emergencies or crime — Seoul Metro is turning to technology. Starting this month, the operator will test an artificial intelligence-driven climate system on Line 4. The system predicts congestion patterns at upcoming stations and proactively adjusts the temperature.
For now, officials recommend tactical seating. Temperatures fluctuate within a single car. The edges near the doors remain the coolest, while the center of the carriage stays warmer.
Source: Korea Times News
