The Cultivation CanonTabatabaei Advising
Water-Activity Science & Dry-Room Engineering

Dry-Room Engineering — Load, Dehumidification & Air-Change Design

Sizing the moisture load a hanging harvest dumps into the room, matching dehu/cooling capacity to it, and engineering laminar airflow that dries evenly without over-drying the surface.

9 min read

A dry room is a moisture-removal machine, sized to a known load

A hanging harvest is not passive — it is a large, slow evaporator dumping water into the room air. At the cut, flower is 75–80% water; the chain removes ~75–80% of wet weight before the endpoint. A 400 lb wet harvest that finishes at ~100 lb dry sheds roughly 300 lb (~36 gallons) of water into room air over 10–14 days, front-loaded into the first 3–5 days when the surface is wettest. If the HVAC and dehumidification can't pull that water out as fast as the flower releases it, RH spikes, VPD collapses, the pull stalls, and you are hours from mold. Engineering the room means matching removal capacity to that release curve.

The rest of this lesson is for members

Unlock every department, SOP, calculator, and setpoint table — plus Leaf, your AI consultant, and interactive diagnostics.

  • All 11 departments
  • Coco & rockwool tracks
  • The full SOP library
  • Leaf AI consultant
Unlock full access membership from $490/yr · or own it for life