Heyo!
We'll I'm about 45 days into my new grow, this is my second grow. 1st grow started in March of '20, although it was cold, it was not as cold and condensation did not appear as much of a problem as it now. My grow tents are in my insulated attic.
I' ve added a 2nd 3x5 tent along with the original 4x4 tent. I have Y's for both the 6" intake and 8" exhaust. This allows me to use the same two roof vents, one for dedicated fresh air and one dedicated for exhaust and are shared between the two tents. The intake & exhaust are NOT mixed, they are both separate and dedicated to their purpose.
I've also made some modifications to the tent by adding insulated foam board, to the 3 primary sides and roof and adds an R6 value. I cut holes in the foam board for the 6" intake and 8" exhaust. For the front door of the tent, I zipped up two sleeping bags as a drape for the front entrance for both tents. It's a pretty nice setup, I'll be certain to add pictures once it's complete.
On to my problem. Last week I went up to water, and noticed water on the floor, outside of the 4x4 tent. That tent sits on a 6x6 platform over the insulated floor of the attic.
Initially, I noticed it was coming from the outside flex duct of the 6" intake, closest to the tent. I dismantled the flex duct and noticed it had a wet interior throughout. Then I checked the 8" exhaust, and felt weight of actual water inside the flex duct, which thankfully, I was able to drain without further issue.
The issue is easy to understand, hot air escaping into non-insulted ductwork that is just above freezing, gets you condensation. I didn't have this problem on my first run, because the temps were more mild and 3 internal fans for air movement.
I purchased 25' of both 6" and 8" R8 insulated flex duct and also picked up 3 - 6" & 3 - 8" spring loaded dampers. My plan is to add the dampers at the initial exits of tent and roof (for both tents). The galvanized Y's are closest to the roof, and the dampers are before the Y at the roof, and before the inline fans at the exits of the tents. I'll include a drawing of this as well.
Once completed, I hope to achieve airflow that doesn't create condensation build up in the ductwork. When I inspected the original flex duct, there was a lot of dust inside and in the original inline 6" fan had mold. I cleaned the inline fan with bleach, and thankfully wasn't using it, as the temps were just to cold to add cold fresh air. But so glad I'm doing this as I've discovered a lot of issues as a result.
I'm currently using one tent at the moment, not taking in fresh air from the outside, only from inside my home using a 6" inline fan with insulated ductwork. Thankfully, I had the knowledge to buy insulated duct for this single run, because it pulls both AC as well as heat - no condensation issues - but I will be inspecting to confirm this.
It's a battle, but I'm committed to making it work. Please let me know if you have additional ideas for me to implement.
Thanks,
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