I have all of my ducts and furnace in a "damp" crawl space. To prevent moisture from coming into the house via the HVAC system I want to seal my ducts as much as possible and would like some advice on the best way to do this. I did have someone seal all of my return ducts with mastic and was wondering if it made sense to do the same with the supply ducts. Is there a better way, etc?
Any advice is appreciated.
George
PS.. BTW.. I did put down 6 mil plastic on the floor of the crawl space to help bring down the moisture it the area.. I also plan on putting a dehumidifier down there with the goal of drying the area somewhat.