Views: 2 Author: Site Editor Publish Time: 2025-11-05 Origin: Site
In densely planted indoor growing rooms, a large number of plants release moisture through the process of transpiration. This process significantly increases humidity levels, creating an unstable environment that can cause mold growth, disease outbreaks, and yield reduction.
Dehumidifiers are therefore essential equipment to maintain optimal environmental balance and plant health.
Excess humidity affects both plant physiology and facility operation:
Mold and Mildew: High relative humidity (RH > 70%) promotes Botrytis, powdery mildew, and root rot.
Poor Climate Control: Air conditioners remove heat but not enough moisture, causing condensation on leaves and walls.
Reduced Growth Efficiency: Fluctuating humidity disturbs the vapor pressure deficit (VPD), slowing transpiration and nutrient uptake.
Equipment Stress: Continuous condensation damages lighting fixtures, fans, and HVAC coils.
The grow room dehumidifier helps maintain a stable and healthy microclimate by:
Removing excess water vapor released by plants.
Maintaining target RH between 45–65%, depending on the growth stage.
Stabilizing VPD to enhance nutrient absorption and photosynthesis.
Reducing the microbial load and improving air hygiene.
Supporting HVAC systems to achieve energy-efficient climate control.
Type | Working Principle | Advantages | Typical Use |
Condenses moisture by cooling the air | Efficient at ≥20 °C | Common for vegetative & flowering stages | |
Desiccant Dehumidifier | Uses a moisture-absorbing wheel | Effective in cool or dry rooms | Ideal for low-temp or post-harvest areas |
Integrated HVAC Dehumidifier | Combines cooling, heating, and moisture control | Precise, automated climate management | Large commercial grow facilities |
Capacity Sizing:
Estimate total moisture load using transpiration rate per plant:
Moisture Load = Number of plants * Water loss per plant/day.
Example: 200 plants * 0.7 L = 140 L/day (≈ 300 pints/day capacity).
Air Circulation:
Ensure even air mixing around dense canopies; avoid stagnant zones.
Placement:
The wall mounted dehumidifier saves floor space and ensures balanced RH.
Automation:
Integrate RH and temperature sensors with smart controllers to maintain setpoints across light/dark cycles.
Drainage:
Provide continuous drainage to prevent overflow and bacterial growth.
Growth Stage | Temperature | Relative Humidity | VPD |
Vegetative | 24–28 °C | 60–70% | 0.8–1.0 kPa |
Flowering | 22–26 °C | 45–55% | 1.0–1.2 kPa |
Late Flower / Drying | 20–24 °C | 40–50% | 1.2–1.4 kPa |
Consistent plant growth and higher yields
Reduced risk of mold, mildew, and disease
Improved energy efficiency of HVAC systems
Stable climate even during dark periods
Better product quality and aroma retention
In densely planted planting rooms, dehumidifiers are not optional—they are critical components of environmental control. By stabilizing humidity, improving air quality, and protecting against mold, they directly contribute to stronger plants, higher yields, and safer operations.
