What Is Dew Point and Why Does It Matter in Drying?

Dew point is a specific measurement of humidity, not just a percentage. It tells you the exact temperature air must reach for water vapor to turn to liquid. This is different from relative humidity, which changes with temperature. Knowing the dew point gives a clearer picture of how much moisture is actually in your indoor air after a leak or flood.

When air holds the maximum amount of moisture it can, it is saturated. The dew point is the saturation temperature. If the air temperature drops to or below this point, you will see condensation on windows, pipes, or walls. This is why a cold soda can "sweats" on a humid day; the can's surface is below the dew point.

Water damage professionals use tools like thermo-hygrometers to track dew point. They take readings of air temperature and relative humidity in different rooms and within wall cavities. These readings let them calculate the current dew point. By comparing it to surface temperatures, they can predict and prevent condensation before it causes more damage.

This monitoring guides their equipment setup. They may adjust air mover placement to warm a cool surface or use a different type of dehumidifier. The process is not static; as drying progresses, the dew point changes. Continuous monitoring allows the pros to adapt their strategy, ensuring efficient drying and protecting your property from secondary issues like mold.

• Thermo-hygrometers measure air temperature and relative humidity.
• Psychrometric charts convert these readings to find the dew point.
• Infrared thermometers check surface temperatures of walls and floors.
• Data loggers can track conditions over many hours or days.
• This data shows if a surface is at risk of condensation.
• Adjustments to equipment are made based on these readings.

While controlling dew point requires professional equipment, you can help by promoting good airflow. Keep interior doors open and avoid piling wet items against cold exterior walls. If you use portable heaters, do so with extreme caution and never leave them unattended, as they can be a fire hazard. Your main job is to report any new damp spots or odors to the pros immediately.

Ventilation is helpful but has limits. Opening windows can sometimes introduce more humid air, raising the dew point indoors. Outdoor humidity changes frequently with the weather and seasons. It is generally better to let the restoration pros manage the indoor climate with their sealed drying system. Trust their measurements and follow their specific advice for your home.