It is a worldwide problem for which three students (5 vwo) from De Nieuwe Veste in Coevorden are trying to find a solution in the coming months: the noise that heat pumps make. Well, during the day the noise is often not too bad. But especially in the evening and at night the hum of installations can be clearly heard. Especially close to the bedroom window. And even more so if it concerns the heat pump of the neighbours.