Should you keep crawl space vents open or closed? 'If you close unsealed ones without a dehumidifier, you're in trouble' – experts reveal how and when to close for less moisture, mold, and better energy efficiency in your home

Clean and tidy luxury living room with working fireplace, dining table and snow view.

Knowing whether to keep your crawl space vents open or closed at particular times of year will transform the moisture levels in your home. But get it wrong, and it could lead to wider structural issues needing expensive repairs or mold remediation.

Knowing how to reduce humidity in a house and in a crawl space will help eliminate these issues and bring with it plenty of benefits including lower bills and less time spent on maintenance or dealing with mold.