In Japan, summers seem to get hotter every year. One step out of the door, and you’re immediately wrapped with moist, hot air. The lingering heat of late summer seems likely to continue this year as well.
As the hot days stretch on, one thing that becomes more noticeable is the air conditioning on trains. Sometimes it offers a moment of relief away from the heat outside, while other times it feels excessively cold. Lately, during the intense heat waves, “mildly air-conditioned cars” on trains have been a topic of criticism on social media. It raises the question: given climate change, are some of Japan’s trains just too damn warm?
A slightly higher temperature for the sensitive
Railway companies are making various efforts to provide a comfortable temperature for passengers. Still, they continue to receive feedback from passengers saying it’s both “too cold” and “too hot.”
People took to X (formerly Twitter) to complain. “Do we really need mildly air-conditioned cars?” “If we have mildly air-conditioned cars, we should have strongly air-conditioned ones too.”
On the other hand, some people comment that “the regular cars are too cold without mildly air-conditioned ones.” Someone else commented, “Even the mildly air-conditioned cars have plenty of cooling.” At times, the debate heats up so much that the phrase “mildly air-conditioned car” (弱冷房車; jakureibousha) trends on social media.
Just as some people are more sensitive to heat or the cold, perceived temperature varies from person to person. The major railway companies in the Tokyo metropolitan area, such as Odakyu Electric Railway, Keio Corporation, Tobu Railway, Seibu Railway, Keikyu Corporation, Tokyu Corporation, and Tokyo Metro, all set their regular cars at 26°C and mildly air-conditioned cars at 28°C. JR East, on the other hand, varies by line. For example, on the Yamanote Line, regular cars are set at 25°C and mildly air-conditioned cars at 27°C.
The Tokyo Metropolitan Bureau of Transportation (Toei Subway) sets the temperature on the Asakusa, Mita, and Shinjuku lines at 25°C for regular cars and 28°C for mildly air-conditioned cars. However, the Oedo Line sets its temperatures significantly lower, at 22°C for regular cars and 24°C for mildly air-conditioned cars. This adjustment is necessary because Oedo Line trains are smaller than those on other lines. The reduced interior space makes it harder for cool air to circulate effectively, so the temperature is set lower to compensate.
But why those temps?
According to JR East, they introduced mildly air-conditioned cars “to ensure a comfortable experience for passengers who are sensitive to air conditioning.”
Private railways in the Tokyo metropolitan area set their regular cars at 26°C and mildly air-conditioned cars at 28°C. However, different railway companies don’t coordinate on this temperature setting.
Seibu Railway explained, “We made our decision based on customer feedback and requests.” Since many lines in the region are interconnected, maintaining the same temperature settings is practical for operational purposes.
In April 2011, following the Great East Japan Earthquake, Tokyo Metro raised the temperature of all train cars to 28°C as part of energy-saving efforts. However, this led to a flood of complaints that it was “too hot.” By July of that year, they reverted to their usual temperature settings.
A spokesperson from the public relations department noted, “Energy conservation is difficult to achieve through air conditioning alone. We’re aiming for significant energy savings across the entire vehicle, including switching to LED lighting and improving control systems while balancing a comfortable interior environment with energy efficiency.”
Regularly monitored and adjusted
However, factors such as weather and crowd density can affect passengers’ perceived temperature.
To address this, for example, Tobu Railway has conductors “periodically turning air conditioning switches on and off to maintain appropriate temperatures.” Seibu Railway says that “conductors are instructed to regularly check the situation and manage temperatures with precision.” Tokyo Metro also mentions that “crew members adjust the air conditioning based on outside temperature and crowd density.”
All companies strive to ensure that conductors, by stepping out from the conductor’s cabin to the passenger areas, can personally assess adequate temperatures. However, with some lines having trains with more than ten carriages, monitoring crowd conditions in every carriage is challenging.
To overcome this, an increasing number of railway companies are equipping newly manufactured trains with systems that automatically regulate air conditioning.
Seibu Railway explains, “By automating the air conditioning systems, we adjust temperatures automatically based on the train’s crowding and the outside temperature. The system can also perform dehumidification automatically if the humidity is high, even if the temperature is set below the target.” Toei Subway adds, “Sensors automatically adjust the air conditioning to maintain the set temperature.”
Complaints go both ways
Railway companies seem to be aware of the debates on social media to varying degrees, and it’s evident that they are struggling with how to respond.
JR East stated, “We have been paying close attention to the recent extreme heat internally. However, we receive not only complaints about the interior being too hot but also feedback that it’s too cold. Therefore, we believe the need for mildly air-conditioned cars remains unchanged.”
Tokyu Corporation also shared, “While we receive feedback that the cars are ‘too hot,’ we also hear complaints about the air conditioning being ‘too cold,’ indicating that we are struggling to provide a comfortable environment for all passengers. We are considering adjustments to the temperature settings based on passenger feedback.”
As temperatures rise, advancements in vehicle and air conditioning technology continue. It’s crucial to consider not only passenger comfort but also the integration with other railways, the connection between lines, and the overall train composition. Operating mildly air-conditioned cars is proving to be more challenging than expected.
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Sources
それでも「弱冷房車」が必要なワケ 首都圏の鉄道事業者、設定温度や運用方法の違いは AERA dot.
寒い？暑い？電車の冷房 毎日新聞生活報道部
最も設定温度が低い路線は？首都圏電車の冷房事情 ウェザーニュース
