At a home & garden show today, I saw a number of vendors pushing their
encapsulated crawl space, mostly CleanSpace brand. In some ways it sounds
attractive but they claim you need no vents and no dehumidifier. It seems
to me that with no air movement there will be inevitable humidity build up
due to small leaks, air conditioning ducts etc. and that the mold problem
could be increased rather than eliminated (dark, moist, little to no air
movement).

Does anyone have experience with these? Good or bad experiences? If so,
how long has it been installed?