My house crawl space has visible moisture vapor coming out of the crawl space vents especially noticeable in the morning which is visible as vapor and condensates on the siding. We have hardly had any rain yet, it has yet to get very cold and require much use of our heating but the amount of moisture that is coming out baffles me. Any ideas why? It does raise the humidity level in the house a noticeable amount as well. The worst area is in a portion I cannot crawl to as it was added on with no access. That one also has only two vents. I intend to add some. Out here we never close off our vents like some areas of the country do.