After sealing and insulating this crawl space, we need to make sure we control the relative humidity. This is achieved by installing a dehumidifier with a hygrometer. The dehumidifier will be set to cut to on when the humidity reaches about 55% our goal is to prevent it from getting high enough that microbial growth can occur in the crawl space. We don't want the space to be too dry either because that can be damaging to the home's structure as well. A hygrometer is provided to the homeowner that allows them to monitor the temperature and relative humidity in the crawl space from inside their home.