Our problem is dampness in the crawlspace. In order to correct this situation we are piping the downcomers away from the house and are also doing a minimum of grading away from the house (as much as we can). We are also considering putting two vent fans in existing vent spaces, fans to be humidistatically controlled. What would be a good setting for the humidistats? We live on the Cumberland Plateau in Middle Tennessee, elevation approx. 2200 feet.