How do we eleminate an odor coming from our crawlspace? The space is dry, with 2 layers of 6mm plastic on the dirt floor. There is no water in the crawlspace, and all walls are dry. But in spots mositure has a accumlated under the plastic. In the summer we open the vents to the space and we recently installed a small exhaust fan to help move air through the space. This has helped reduce the odor a lot. We live in the Upper Ohio Valley, where the summers can be quite hot and humid, and the winters very cold. Since the heating systems and all utility lines are in the crawlspace the vents must be closed in the winter to prevent freezing of the utillity lines. We are very concerned that the odor will be a problem in the winter months. Any help would be appreciated.