Inline exhaust - Fantech

For comparison, I've installed a Fantech inline exhaust fan for the Powder Room. Its circular plastic housing contrasts with the rectangular metal Panasonic installed in the small bathroom. The instructions for this unit say that any mounting orientation is okay but vertical is best for gravity drainage of condensation. Makes sense. Finding a good spot to do so then becomes the challenge.

I went extreme and mounted it 25 feet away, on the gable wall, using up the entire run of insulated 4" duct. At 100 CFM (their smallest unit), it's oversized for the 156 cubic-foot room anyway, so slight reduction in velocity is okay. Testing reveals sufficient air movement. The only noticeable noise is the "wind" blowing past the dampers. Maybe it'll be totally silent with the grille in place.

Cost for the complete kit with halogen light (model PB 100H) is $203 delivered. Cost of ductwork, wall vent, supplies is $50.

I think the ideal combination would have been using a semi-rigid duct (lower part in photo) for the inlet side as well, instead of the plastic-wrapped-wire type (top in photo), with the Fantech mounted no more than 10 feet away from ceiling grille. Insulation would be necessary in colder climates. The drawback in using very flexible duct is the restriction of air flow when the run is long and/or not fully stretched.