The video shows the retrofit of a ventilation system using ebm-papst EC fans. It shows that it is perfectly possible to optimise the energy use of a ventilation system without replacing the ventilation unit.
One way is to look at the fan, the most energy-consuming component in a ventilation system. If the system ism ore than 10 years old, then it is most likely equipped by a belt-driven fan. This can be replaced by a centrifugal fan, which has a combined and optimised impeller and EC motor, making it a highly energy-efficient solution. This also makes frequency converter, shielded cables and motor protection unnecessary. Before replacing and AC fan with an EC fan the airflow and pressure of the existing fan needs to be determined, in order to match the airflow performance of the new fan with the existing one.
The video continues to show the rollout of the retrofit. Replacing an old, belt-driven AC fan with an ebm-papst EC plug fan typically results in a 30-70% energy saving. The power usage in the case shown was more than halved, from 510W usage of the AC fan (already frequency regulated) to 214W usage of the EC fan. This means that the investment is typically recovered in 2 to 2.5 years.