A crawl space sizing table in current DOE pints, why sealed vs vented changes the answer more than square footage, and why undersizing here goes unnoticed for months.

Barrier first, dehumidifier second. What a crawl space vapor barrier does, what thickness to use, what encapsulation adds, and when a liner alone is enough.

What crawl space humidity should be, why published targets range from 30% to 60%, and why opening the vents in summer makes a crawl space wetter rather than drier.

Why a portable dehumidifier is the wrong tool for a crawl space, what a real crawl space unit has that household models do not, and why sealing the ground and vents has to come before the machine.