Final answer:
When condensation forms on the inside of a window due to outdoor temperatures dropping, the humidistat should be decreased to prevent further condensation and maintain indoor humidity levels between 30 and 50 percent.
Step-by-step explanation:
If condensation occurs on the inside of the window when the outdoor temperature drops, the humidistat should be decreased. Condensation on the inside of the glass typically occurs when the warm, moist air inside the room comes in contact with the cold pane of glass, causing water vapor to condense. To prevent this condensation and maintain indoor humidity between 30 and 50 percent, reducing the humidity setting on the humidistat is necessary. This helps reach a lower humidity level inside the room, which reduces the likelihood of condensation on the windows. Remember that the dew point is the temperature at which relative humidity is 100%; it's the temperature at which water starts to condense out of the air.