For most managers of critical cleaning operations, drying is synonymous with evaporation.

YOU HAVE TO HEAT THE PART, TOO
Consider this example of evaporative drying of water, which should be an easy task. Assume: a one quart stainless steel saucepan, half-full of water, on an electric stove. It is desired to evaporate all that water in five minutes.

The energy demand to evaporate this water is equivalent to one ton of refrigeration (12,000 BTU/hr). But since it is necessary to heat the stainless steel saucepan as well, to evaporate the contained water, the energy requirement is equivalent to the refrigeration requirement to cool a large home.

In other words, not only does water have a huge heat of vaporization vs. solvents (~1,000 BTU/lb vs. ~250 BTU/lb), but one can’t just evaporate the water from surfaces without wasting heat in heating the surface material too.

AIR AND WATER
Drying generally means evaporation of water. It takes a lot of energy, and a lot of time, to evaporate a little water. The rate of drying parts is limited by the rate at which heat can be transferred from hot air to the water, causing it to evaporate. Slow heat transfer from heated air to wet parts is normally the rate-limiting process step. Even worse, air doesn’t have a high capacity to carry heat or water. Consequently, huge volumes of hot air can be required.