Make sure that crawl space vents work and are not blocked. If your cooling ductwork runs through the crawl space, consider closing crawl space vents during summer cooling months. Using vent fans in crawl spaces during the summer when humidity is high may increase the relative humidity in the crawl space and inside the home. Use fans only when outside humidity is well below 50 percent. Mechanical dehumidifiers reduce humidity in basements, but they should not be used in crawl spaces when vents are open.
Some firms advertise disinfectants and sealants to prevent further fungal growth.
It is uncertain whether these processes are appropriate for most homes. Have microbial contamination verified by an industrial hygienist or other environmental testing agency before sanitizing products are used in your ductwork. Commercial fogging or misting agents should not be used because of possible health problems from breathing these chemicals. Use of a sealant in the ductwork is generally not appropriate unless the mold, mildew, or dust source has been removed. Dust Mites It is not known how well any single measure controls dust mite populations.