Well thought out down to the last detail: Why the Sensorbottle needs a fan.
In physics, there is a beautiful theorem: no energy is lost (law of conservation of energy). Not that we want to bore you with physics-based cleverness - on the contrary: the Sensorbottle also consumes electrical energy. In our case, this is primarily used to generate heat and some light for the display. Now you might think that this is very little energy. That is essentially true. In normal operation, it is around 0.8 watts/h. Still sounds low? It is. But even a small LED with 1W, for example, gets quite hot in continuous operation.