Hey Nik, 25l/s or 90 cm p/h for an intermittent bathroom fan is what’s recommended. Some of the three in one units say they can do over 90 cm p/h hour but my understanding is the fan units are too small and easily clogged for efficiency. And those units are never really going to be placed above the moisture source, so single fan units are the better choice.

Apparently there are new/efficient three in one units on the market now though. Ian Mayes?