When warm, humid air enters crawl space vents, where is the first place it will give up its moisture? On the coldest surfaces, right? The coldest surface is likely to be your ducts when the air conditioning is on. Water is a conductor, not an insulator. So when a duct is wet, it is warmed by the summer air that came through the crawl space vents.
Houses with dirt crawl spaces have damp air. Damp air uses more energy to heat and cool, and this costs more money. Damp air puts more of a latent (hidden) load on the HVAC system. Everyone knows they need to run their AC more on a humid day, but what if the humidity is coming from inside the building?
The crawl space encapsulation system completely isolates your home from the earth. This dramatically reduces the humidity level in the air which, when combined with sealing outside air and dehumidification, will reduce heating and cooling usage, eliminate condensation, mold growth and wood rot from a crawl space, and make the whole house healthier.