Psychrometrics
The science of how air holds moisture at different temperatures, the technical basis restoration technicians use to actually plan and monitor a structural drying job, rather than just running fans and dehumidifiers and hoping for the best.
Why it matters
Advanced restoration credentials like IICRC's Applied Structural Drying (ASD) teach this directly, since a drying plan built on real psychrometric readings, temperature, relative humidity, and grains per pound of moisture, catches hidden moisture that a purely visual inspection misses.
On a real project
A technician tracks relative humidity and grains per pound at set intervals throughout a drying job, using the readings to confirm the structure is actually approaching a dry standard rather than just assuming it is because the carpet feels dry to the touch.
Who this matters most to
A Restoration Project Manager relies on psychrometric readings to decide when a job is genuinely finished and walls can be safely closed back up, rather than guessing based on how the space looks or feels.
Where this goes wrong
A drying technician runs equipment on a job without tracking psychrometric readings at set intervals, so nobody can prove the structure actually reached a dry standard before the walls go back up. Hidden moisture left behind grows mold weeks later, reopening a claim that should have been closed clean the first time.