I had my Aprilaire Model 700 Humidifier Mounted on Return duct next to the furnace. Now I can her that sucker every time it is on. It is loud and annoying. The sounds just carries through the return duct all the way to my return grille. The return is about 20ft long. Rigid metal duct.
Besides having my humidifier moved back to the supply side, what are my options here?