Indoor humidity levels should be kept at 50 percent or lower. Keeping humidity down helps to keep mold and spores at bay, and helps to cool the home.
If the humidity is too low, it can cause problems like dry skin and static electricity. During the winter, indoor air tends to be drier, which is why some households use humidifiers. Nonetheless, it is recommended that home owners not exceed certain humidity levels at certain temperatures to avoid condensation on the windows. For instance, from 20 to 40 degrees Fahrenheit, humidity should not exceed 40 percent, while at 10 to 20 degrees Fahrenheit, it should not exceed 35 percent.