Why are Planus Toilets absolutely the most silent?
The noise of the vortex pump is due to the cavitation issue, caused by the presence of some air in the pump, that is inevitably sucked through the toilet drainage hole at the end of each discharge sequence. That air remains caught in the upper part of the pump.
PLANUS worked radically the problem out by adding, in the upper part of the pump, the "automatic vent air discharge". This innovation, for whom a patent has been duly deposited, has practically solved the noise problem enabling the pump to run imperceptibly and increasing considerably its performances.