The magical 19 degrees – how the BVG’s radiators work
You’ll probably recognize the following situation: you’re sitting in one of our trams, the sun is blazing, and yet the tram’s radiator is still on at full blast, making you feel like you’re in a sauna. At this point you’re probably wondering why the staff won’t do anything about it. The reason: The heaters in our vehicles operate automatically and heat the passenger area according to the external temperature. If the temperature outside drops below 19 °C, the heating automatically turns on. The tram staff can only adjust the temperature for their driver’s cabin.
This is handy for our drivers, as they can fully concentrate on driving and don’t have to constantly keep an eye on the thermometer. For you, it means you don’t have to ask anyone to turn on the heating. Ideally, our vehicles are always heated to a comfortable 19° C. In the example mentioned, however, that is not the case because, despite the bright sun, the outside temperature is too low, meaning that the heating is automatically on instead of air conditioning.
The BVG bus radiator
In our buses the radiators also automatically turn on when the outside temperature drops below 19 °C. The drivers can manually turn the heater on and off but cannot control it beyond that. So, if the bus feels like a sauna, you can always politely ask the driver if the heater can be turned off.
Special case: our subway
In our underground trains, things work a bit differently. On the lines U6, U7, U8, and U9, the heating is currently set to 15 °C instead of 19 °C. This is because these trains run purely underground, meaning they are protected from wind, rain, and the cold and therefore do not cool down as quickly as our above-ground trains. These few degrees of difference are hardly noticeable and allow us to save energy and be more environmentally friendly.
Why was it still so cold on the bus/subway/tram recently?
On very cold days, our vehicles can unfortunately feel chillier than usual. Every stop at which the doors must open and close means cold air flows in and warm air flows out. If it’s particularly frosty outside, the cold air may not be sufficiently warmed up by the next stop before the doors open again and let in more cold air.
It could also be the case that you catch a bus, subway train, or tram that has just left the depot. Our vehicles are parked outside at the depots overnight and therefore cool down quite a bit. Once they start running, it takes a while for everything to warm up again, and it can feel cold despite the heater.
Despite this it will never be colder inside the vehicles than outside. Pro tip: To help us, you can manually close the doors in our subway trains at each stop by pushing the button located at the top left of the door frame, preventing cold air from flowing in.
Conclusion: Be like an onion!
As you can see, our heating systems theoretically ensure that our vehicles always have an optimal comfort temperature. Unfortunately, this doesn’t always work in practice due to various factors beyond our control. Therefore, our tip for you: Dress in layers like an onion!