It can also discolor leather and paper. Molds which cause mildew need moisture and certain temperatures in order to grow. Mildew is most likely to develop in closed houses during humid summer weather. The best way to prevent mildew problems is to control the source. Mold spores are present in the air and will settle onto surfaces if there is sufficient moisture.
Warm air can hold more moisture than cool air.
By air conditioning potential mildew areas, you can effectively cool and circulate the warm air. If an area of the house lacks air conditioning, an alternative might be a mechanical dehumidifier. Doors and windows should be kept shut in the areas where the dehumidifiers and air conditioners are in use. Dampness in homes also can be removed by turning on the heat for a short time. After turning the heat off, open the doors and windows to let out the moist air.