Do You Need a Dehumidifier for Your Grow Room?
By The Budometry TeamPublished Updated
A flowering plant releases nearly all the water you give it back into the air. In a sealed tent in a humid climate, that air has nowhere to go.
Part of our pillar guide: Grow Room Climate: Temperature, Humidity, Airflow and Smell
When you need one
If your late-flower RH sits above 55% overnight, you need dehumidification. Bud rot on a dense cola can destroy weeks of work in 48 hours and it is not recoverable.
Sizing
A 30-pint unit handles a typical 4x4 tent in a moderately humid room. Larger spaces, multiple tents, or coastal climates want 50 pints or more. Undersizing means the unit runs constantly and still loses.
Cheaper options first
Increasing exhaust rate, dehumidifying the room the tent sits in rather than the tent itself, and reducing the lights-off temperature drop all lower RH for less money and less heat.
Frequently asked questions
- Where should the dehumidifier sit?
- Outside the tent, conditioning the room air the tent pulls from, if you have the space. Inside a tent it adds meaningful heat.
The full guide on this topic
Grow Room Climate: Temperature, Humidity, Airflow and Smell
Stage-by-stage temperature and humidity targets, VPD explained simply, how to size an inline fan, and how a carbon filter keeps a flowering tent from being noticed.