As I progress in modding and repairing (leaks!) our 1996 Casita
Sprit. I'm doing away with the original noise box...I mean, range hood. Among other things I'm installing an Endura range vent. I've modified the louvered (not original type) Ventline range vent, that was on the exterior, to be my interior piece. It's flange fits in the flange of the Endura. It just so happens that three-3" muffin/computer fans fit "just right" in the Ventline louvered vent.
So my question is...do I NEED three fans? Or will two do fine? Two would; be cheaper, use less power, and allow my to make an internal lever for propping open the exterior vent flap. But, if I NEED three? I'll do three.