Gas Fitter Practice Test

If condensation occurs on the inside of a window when the outdoor temperature drops, what should be done with the humidistat?

1. Increased

2. Set to Zero

3. Set to 100%

4. Decreased

The correct answer is: Decreased

The correct action when condensation occurs on the inside of a window, indicating high humidity levels within the home, is to decrease the setting on the humidistat. Lowering the humidistat allows for a reduction in indoor humidity, which can help mitigate condensation problems. Condensation forms when warm, moist air in contact with a cold surface cools and loses its capacity to hold moisture, leading to water droplets forming on surfaces like windows. By decreasing the humidistat setting, you are effectively reducing the moisture level in the air, which helps to maintain a more balanced humidity level conducive to preventing condensation. This is particularly important during colder weather when the temperature difference between indoors and outdoors is more pronounced. The desired outcome is a more comfortable and healthier indoor environment, free from the issues associated with excess humidity, such as mold growth and damage to surfaces. Choosing other settings, like increasing the humidistat or setting it to extremes (zero or 100%), would not address the underlying condensation issue effectively and may even exacerbate humidity-related problems.