The acronym of HAT is used for teaching drying – Humidity, Airflow and Temperature. These three elements make up what is called the drying pie. Increasing any of the “slices” would decrease the need for the others. The inverse would be true, as well.
Humidity and Airflow seem to get the most attention. Temperature control is usually limited to keeping the temperature in optimum range for dehumidifiers and the comfort of the occupants, but when properly applied, temperature, in the form of heat energy, can a very effective drying tool.
Great advances have been made in recent years in drying equipment and methods, but there remains a bottleneck to our current drying systems. This bottleneck is evaporation. We have excellent equipment for removing water vapor from the air, but we have been limited in the ability to get the vapor into the air – evaporation. The surface water evaporates very quickly, but the water contained in the materials (hardwoods, carpet cushion, sub-floors, sill plates and wall boards) can take days to remove. If we could speed that process, we could speed the overall drying process.
How does evaporation work?
Water exists in three different phases – solid, liquid and vapor. What causes it to change from one phase to another? It is the addition of energy or heat. The phase change from liquid to vapor is our main concern and what we call evaporation. Energy (heat) and airflow applied to directly to water (liquid) will speed the phase change to vapor causing evaporation.