That 6,500-square-foot rating on the box doesn't survive contact with a real crawl space — piers, ductwork, and corners change the math. Here's why dehumidifier sizing takes an actual inspection, not a formula.

Expect a real drop in humidity within a day and a stable crawl space inside a week. But if the structural wood is soaked, drying it out slowly over several weeks is the better long-term fix.

North Carolina is really three climates, so the answer depends on where you live: run it year-round in the Piedmont and on the coast, where winter warm spells spike humidity. Mountain homes get a break.

You don't need technical know-how to judge a crawl space job — just a flashlight and two minutes. Learn the fastest tells: a flat, tidy barrier, tight sealed seams, and whether the dehumidifier matches the quality of the work.