The Complete Guide to
VPD Management
Vapor Pressure Deficit (VPD) is the single most important environmental metric for cultivation success. This guide teaches you how to measure, maintain, and optimize VPD for maximum yields and zero pathogen outbreaks.
What is VPD?
Vapor Pressure Deficit measures the difference between the amount of moisture in the air and how much moisture the air can hold when saturated. It's expressed in kilopascals (kPa) and directly affects plant transpiration.
Why VPD Matters
- Optimal transpiration: VPD 0.8-1.2 kPa drives nutrient uptake without stressing plants
- Pathogen prevention: VPD below 0.8 kPa creates wet leaf surfaces where PM and botrytis thrive
- Yield maximization: Proper VPD management increases yields 15-25% compared to temperature/RH alone
Optimal VPD Ranges by Growth Stage
Seedling/Clone
kPa
Young plants need lower VPD to reduce transpiration stress while roots develop.
Vegetative
kPa
Vigorous growth phase benefits from higher VPD driving nutrient uptake.
Flowering
kPa
Higher VPD prevents dense flower moisture accumulation and bud rot.
How IOGRU Maintains Optimal VPD
Manual VPD management is nearly impossible—temperature and humidity fluctuate constantly, requiring immediate coordinated responses from multiple systems.
Continuous Monitoring
Sensors measure temp/RH every 30 seconds in every zone, calculating real-time VPD with ±0.05 kPa accuracy.
Predictive Adjustments
Machine learning predicts VPD drift 30 minutes before it happens based on lighting schedules, weather, and historical patterns.
Coordinated Response
IOGRU simultaneously adjusts HVAC, dehumidification, and air circulation to bring VPD back to target in under 60 seconds.
Ready for automated VPD management?
See how IOGRU maintains perfect VPD 24/7 without manual intervention.
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