When It Is Not Your Humidity

• Fog between the panes
• One window always worse
• Water after rain, not on cold mornings
• The whole home stays humid no matter what
• Questions worth asking a professional

Sometimes the glass is telling you about hardware or the building envelope, not about last night’s shower.

§Fog between the panes

If droplets sit inside a sealed double- or triple-glazed unit and you cannot wipe them from either side, the sealed unit has failed. Lowering indoor humidity will not clear it. Repair usually means replacing the sealed unit or the sash, not buying another humidifier setting.

§One window always worse

Compare it to similar windows in the same room. Check coverings, furniture, a blocked heat register, drafts at the frame, or a damaged seal. A single chronic offender is often local.

§Water after rain, not on cold mornings

Condensation tracks outdoor cold and indoor moisture. Leaks track weather. Note whether water appears after rain or snowmelt, runs from the top of the frame, or shows on walls below flashing. That path needs weatherproofing diagnosis, not only a dryer bedroom door.

§The whole home stays humid no matter what

If logs show high RH after source control, fans, and humidifier changes, look for hidden damp (basement, crawlspace), undersized or failed ventilation, or building moisture. That is the point to bring in a qualified contractor or HVAC technician with your log in hand.

§Questions worth asking a professional

• Is the water on the room side, between panes, or from a leak path?
• Do bathroom and dryer vents terminate outdoors and flow well?
• Is there an HRV/ERV, and is it set and maintained correctly?
• Are any sealed units failed?
• Is basement moisture contributing to whole-home RH?

Bring your seven-day log. Measurements beat vague descriptions.

Originally published at https://dry-glass-notes.surge.sh/articles/when-it-is-not-humidity.html (AI-assisted, sources cited). If this helped, zaps go to hollisvarrow3753@coinos.io.