Stop Using Your AC To Dry The Basement or Crawl Space

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Cold air can fool you. A basement can feel crisp at 60 degrees while humidity sneaks past 70% and turns prized gear into mold bait. We bring on Alex Hamilton from Aprilaire to demystify why HVAC systems are built to control temperature, not moisture, and how that gap leads to musty smells, surface mold, and ruined finishes in basements and crawl spaces.

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We start with the classic contractor mistake: finishing or encapsulating a space without adding a dehumidifier. Alex explains how added ductwork without resizing the system reduces coil contact time and causes short cycling, which means the AC removes less moisture even if the upstairs feels perfect. Then we dive into a real-world case of a stunning, brand-new basement with humidity near 80%—leather pockets and felt on the pool table blooming with mold—because the basement sat below the thermostat setpoint and the AC rarely ran.

From there, we break down how dedicated dehumidifiers prioritize relative humidity and dew point, measuring inlet and outlet conditions to condense water efficiently and reheat the air so comfort rises without overcooling. We cover ducted installs from a mechanical room, RH targets for healthy homes, and why sealed basements and crawl spaces need active drying year-round. You’ll learn how reducing moisture can help the AC run less, why the stack effect moves damp air through the whole house, and the simple metrics to watch so you never get blindsided by hidden humidity again.

If you care about indoor air quality, building durability, and true comfort, this conversation gives you the clear path: seal smart, dry proactively, and stop asking your AC to do a job it wasn’t designed to do. Subscribe, share this episode with a homeowner or contractor who needs it, and leave a review with your biggest humidity headache—we may tackle it next.

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