VPD = leaf ↔ air moisture gap
Higher temp + lower RH
→ High VPD (dry)
Higher RH
→ Low VPD (humid)
Grow stage
1.51
kPaToo dry — raise RHTarget: 0.8–1.2 kPa · Vegetative
Action steps
- VPD is too high — air is dry · run humidifier or ease AC dehumidifying
- Raise RH during lights-on · verify humidifier / mister output
- Avoid harsh direct fan on leaves — leaf edge burn risk when VPD is high
VPD control gear
Sensors + RH tuning for the grow space
Temp + humidity sensor
Monitor room RH and temp — baseline before tuning VPD
Dehumidifier
Use when RH is high / VPD too low
Humidifier
Use when RH is low / VPD too high
Inline / exhaust fan
Air exchange · helps lower RH and even humidity
Humidity / temp controller
Auto on/off for humidifier or dehumidifier
AI guidance only — not scientific certification. Consult an expert before major decisions.
