In the structural drying industry, all drying utilizes heat drying in some form or another. Energy is required to clear the latent heat of vaporization—that is, the amount of energy necessary to convert a liquid into a gas. Although this IS why we use heat drying, theory alone does not contextualize the technique. The equipment and effectiveness of heat drying have been hotly debated over the years, and it may be time to properly frame what we mean by “heat drying.”
Our industry has come a long way with equipment in its history. Despite all of the improvements in extractors, air movers, and dehumidifiers, the evaporation process remains the bottleneck. When the molecules escape a wet surface (liquid) in a phase and change to vapor (gas), it takes energy (heat) with it. This cools the surface making it harder for more molecules to change phases. Eventually, evaporation ceases or slows so much that no practical progress is made. Restoration contractors need to make sure that doesn’t happen, so what do they do? We are forced to continuously add energy back to counteract the cooling effect of evaporation until all of the excess moisture is removed. Traditionally, we’ve added dehumidifiers that are producing hot/dry air and air movers to transfer energy into the wet materials (liquid).