The purpose of installing a dehumidifier is to maintain proper humidity levels, slow down or stop mildew/mold growth, and to aid in air filtration. Humidity levels should be no more than 60% in the crawl space. This is an ideal environment because mold requires temperatures of 70 degrees or warmer, 60% relative humidity or higher, and organic material to grow. Keeping the relative humidity below 60% helps prevent the mold/mildew from growing, The Drying Co. uses the SaniDry Sedona as a preferred product to achieve this.