Understanding Drying Science

Water exists in three different phases- solid, liquid, & vapor. Energy (heat) and air flow applied directly to water (liquid) will speed the phase change to a vapor rapidly evaporating the moisture.

You have experienced this all your life. For example, when you step out of the shower in a steamy bathroom with condensation on all surfaces including the mirror, attempting to wipe the mirror down with a dry towel provides a temporary solution. Due to the high level of humidity still present in the atmosphere the moisture continues to accumulate on the surfaces. However if you were to direct a blow dryer at the mirror it instantly dissipates. The energy from the heat of the blow dryer raises the pressure of the water molecules allowing the molecules to transform from a liquid to a vapor.

Another simple example would be a pot of water on a hot stove vs. a pot of water on a cold stove. Sure the cold pot of water will eventually evaporate, but it will take days or weeks. The hot pot of water will obviously only take minutes, which is a fraction of the time of the cold pot. Although the application of heat while drying a wet structure is not as simple as the listed two examples, the general characteristics justify how much faster evaporation occurs while directly applying heat.