How to Read This Analysis
Exterior cellar walls often stay colder than central room air, especially during warmer months. Moisture risk is determined by what happens at the cold wall surface rather than central room humidity alone.
- Dew Point: The temperature at which water vapor in the air condenses into liquid water.
- Wall Surface RH: As air gets closer to cold exterior walls, it cools down and its localized relative humidity rises significantly.
- Mold Risk Threshold: Mold spores germinate when localized relative humidity at the wall surface reaches 70% to 80%, long before visible condensation forms.
- Actionable Insight: Keep the wall surface temperature at least 3°C–4°C above the dew point to keep wall RH safely below 70%.