Why do I need crawlspace ventilation?

Why do I need crawlspace ventilation?  (FLYER)  The main source of crawl space moisture is caused by ground evaporation and ventilation allows for dissipation of this evaporation.  Proper ventilation exhaust moisture from the crawlspace and replaces it with fresh drier air.  According to the EPA the way to control mold is to control moisture.  Ventilation allows for effective moisture control.  Ventilation also helps to remove odors and radon from the crawlspace.  (PRODUCTS)  For more information about crawlspaces and ventilation go to www.crawlspacedoors.com