Fans are essential to ensure proper ventilation in increasingly airtight buildings, whereby the energy consumption is immense. In order to adapt the volume flow to the demand, the centrally built-up pressure is usually throttled in volume flow controllers, thereby dissipating energy. Alternatively, energy can be supplied through distributed fans in order to reduce the overall energy consumption. We show the potential of the approach in several generic examples and give a calculation rule for the savings. Finally, we show a real case study and analyse the trade-off between number of distributed fans and energy savings.