One fixed number does not fit every day
As outdoor temperature falls, some homes need a lower indoor humidity setting to avoid condensation on windows or other cold surfaces.
The building provides feedback
Persistent window moisture, musty areas or condensation are signals to reduce humidity and investigate. Dry skin and static alone do not prove the correct setting.
Whole-home equipment needs maintenance
Water panels, valves, drains and controls should be checked. A humidifier should add moisture only when the heating system and control logic call for it.