Condensation on walls inside cabinet

Hello to everybody.
This is my first post, been here for a while but mostly lurking and learning :wink:
Anyway here is my story. I started growing a few years ago with a tent, then stopped for a few years and started again a few months ago. I bought a stealth cabinet made of steel, led lights, hydroponic system etc…I am happy with the setup, the cabinet is well made with electrical sockets inside, exhaust fan etc…
The problem I am having is high humidity inside the cabinet and when I say high humidity I mean drops of water on inside walls. Of course “special conditions” must be met for the water drops to occur.
The cabinet is in a room in my basement where the temperature during winter is around 10-12 degrees celsius (50-55F). When my exhaust fan is on there is no problem with humidity at all but temperature inside the cabinet drops to 13-15 degrees (55-60) so I cannot keep it on 24/7. So the method I am using now (3rd week of flowering) is as follows:

  • when the lights go off (8 AM) the exhaust fan goes on for 8 hours dropping the humidity to 50% but also dropping the temperature too much (I guess because outside room is quite cold)
  • after that a dehumidifier inside the cabinet starts working until I get home (usually around 7 PM) and sometimes I’ll leave it one for a few more hours (10-11 PM)…the temperature rises to 25-27 degrees (75-80F) with humidity around 50% when I only use the dehumidifier without the exhaust fan
  • after that I slightly open the cabinet door and turn off the dehumidifer, the temperature drops to 18 (65F) and the humidity rises to 65-70%;
    If I turn off the exhaust fan and the dehumidifier the humidity inside the cabinet rises to 90% in one hour and drops of water form on the walls inside which is absolutely something that I don’t want.

In the next weeks I’ll be leaving for a holiday and wont be home for 7 days. I cannot leave the exhaust fan for 7 days continuously because the plants will suffer the low temperatures. I cannot leave the dehumidifier on for more than 36 hours because it has a small reservoir (1 L) and then it stops working. One of the possible solutions for me would be in buying a new dehumidifer with a bigger tank (5l) that could work continuously for a 5-6 days or do something to remove the condensation inside the cabinet.
Is the cause of high humidity the lower temperature outside, the cold walls of the cabinet inside and the higher temperature inside?
Would it be enough to make the basement room a little bit warmer? Or should I just use some sort of isolation material on the cabinet walls to make ti warmer?

Thanks for your support…


Sounds like a good application for a recycle timer. You just set the timer to run for something like 1 minute, and then off for a few minutes.

Another thought would be to use something like an oil filled space heater in the room to keep the temp up, and then leave your fan on 24/7.

I’m sure there are other things you can do, those just come to mind as easy fixes.


Thanks for your answer. I don’t want to sound like a newbie but should I rub the exhaust fan at the suggested intervals or the dehumidifier?

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I would probably opt for the fan. Those intervals I suggested were just ballpark. You should probably tinker with them a little and see what fits your area the best.

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My friend …this might not seemlike a gooday idea but you can modify the dehumidifier by drilling a hole in the tank and attaching a small hose to drain it into a 5 gal bucket, allowing for more capacity and runtime.


I would suggest leaving fan on 24/7 to prevent mold issues
So tiu uave a carbon filter set up on exhaust if so recycle air back to basement and dont discharge outside
I run a heater to keep my grow space temps in the 69-65 f range
Another this you can do to help with temps and all is run light at night and off durning the day when its warmer