Conditioned Crawl Space

Since there is no return in the crawlspace the supply of conditioned air creates a positive pressure in the crawl area driving any moist air attempting to enter the crawl area back out.
Conditioned crawl space. Thermally sealed from the outdoor elements insulated and integrated into the home s hvac. A conditioned crawl space also known as a sealed unvented or closed crawl space significantly reduces or eliminates many of the problems of the traditional ventilated crawl space. What you end up with is a completely dry mold free bug free environment that will remain roughly the same temperature as the rest of the house. It does this by allowing conditioned air from your home to flow through it in a sealed space which then vents the used air to the outside of your house.
If you are using air conditioning in your home and your home has a crawl space that is not also conditioned you are spending hard earned money that you don t need to. It also puts your ductwork in conditioned space where it belongs and will perform at its best. Adding conditioned air either heated cooled or dehumidified to the crawl space will help maintain. This type of crawl space uses all of the positive parts of the other crawl space designs and leaves.
If you take a look in your crawl space and it has foundation vents dirt floor and insulation in the floor joist or on the walls you have a major leak in your air conditioning. The sheets are glued right at the overlap seams then to the foundation wall. Conditioned crawl space includes a ground completely covered with a vapor barrier with the barrier s seams and junctions as well. You still need to seal the ducts though.
Its band joist and foundation walls are usually insulated too. In a conditioned crawl space a 10 mil polyethylene barrier covers the entire floor with the sheets extending up to 12 to 18 inches up space s foundation wall. A conditioned crawlspace is really no different from a properly built dry basement. For example a fan blowing 30 40 cubic feet per minute of air from upstairs conditioned space into the crawl space provides air exchange and drying while pressurizing the crawl space.
To get the air back upstairs install several transfer grilles in the floor.