08/31/2026
đ˝ Is your bathroom exhaust fan actually working? đ˝
Just because you can hear it running doesnât mean itâs doing its job.
During a recent inspection, the homeowner told me their bathroom exhaust fan had been running for a couple of hours after showering. The fan sounded like it was working, and the ducting we could see in the attic appeared to be properly routed.
But the humidity readings told a different story.
Even after running for hours, the bathroom humidity was still well above acceptable levels, and that excess moisture was contributing to mold growth on the ceiling.
Bathroom exhaust fans have one important job: remove warm, humid air from the bathroom and exhaust it outside. If humidity stays elevated long after a shower, something isnât working properly, even if the fan sounds perfectly normal.
This is why we donât just look and listen during an inspection. We measure.
High humidity + time = the perfect environment for mold growth.
If your bathroom stays humid, mirrors remain fogged up, or surfaces stay damp long after showering, your exhaust fan may need some attention.