I'm living in a four-story townhouse, and I've been struggling with high humidity on the upper two floors, reaching around 65% even when the AC is running. The lower floors stay comfortable at about 48-50%. After a home energy audit that included various fixes like blown insulation and sealing leaks, they assured me the AC was working fine. Despite these improvements, the upper floors still feel damp. I'm trying to pinpoint potential sources of air infiltration before installing a dehumidifier. I suspect the bathroom vent in the top-floor bathroom might be part of the problem. The enclosure seems warm, and when I used an infrared thermometer, it read 90°F, suggesting poor insulation. Could poorly installed bathroom vents be behind the humidity issues I'm facing?
7 Answers
{
r
a
Absolutely! If your bathroom vent duct runs through the attic and isn't properly insulated, it could very well let outside air in—especially if it lacks a flapper to seal it off. If it's routed through bulkheads without insulation, that's also an issue. You've got a good instinct about it being a potential source of humidity.
c
B
That's good to know! Is there an easy fix for someone like me who's not super handy, or would I need a pro for this kind of work?