The temperature of the air determines its moisture-carrying capacity.
Warm air absorbs more moisture than does cooler air.
Therefore, some of the moisture may be condensed out of the air and condensation forms on the cold surface. This phenomenon is illustrated by the condensation on an ice-filled glass in hot weather or condensation on windows in cold weather. Basic construction techniques and procedures can prevent or minimize most household moisture problems. Insulation, weatherstripping, storm doors, and windows used with ventilation can help homeowners maintain comfortable levels of temperature and relative humidity within the house without annoying problems associated with excess moisture levels. Normally, mildew is a problem at a maintained relative humidity level above 60 percent, and static electricity is noticeable in cold weather at levels of 20 percent or lower.