4 Locations
We always want to select a location for our equipment based off having the shortest duct run possible. For example, a furnace or air handler should be located as close to center of the building as possible. Having two short runs in both directions is better than one long one.
For equipment like a bathroom fan, we are limited on where it can be place, but we need to be mindful of where the duct will terminate outside. It may exit the home on the roof or and an exterior wall, but we always want to choose the closest practical location. 17Running the ductwork to the opposite end of the home would not be a wise decision, but may be necessary in some instances. A booster fan would probably be required for that case as the bathroom fan itself would not be enough to overcome the restriction of a long duct run.