Ventilate or Dehumidify?

[kershaw]

Hello,
I just started a room, about 20' by 20' in a basement. Half veg, Half Flower, We have tons of ventilation, 1270 cfm exhaust and a 1270 intake. We went through one cycle and got great yields, very happy. I believe we got such nice yields because of our massive amount of ventilation. Recently though we have been experiencing some powdery mildew, our humidity is 60% in the flower room, about 20% to high. I know we could fix it by getting a dehumidifier but I don't want to sacrifice all the air flow and our awesome ventilation system. I mean it would be pointless to run a dehumidifier, or heaters of any sort if all that air is just getting sucked out in a few seconds. Hopefully someone out there will call me an idiot and tell me the easy fix to lower my humidity and keep my air flow. The RH where I live is about 50% to 70% year round. great for veg, adding more ventilation I don't would work. I have heard a little bit about pre-grow rooms, where you dehumidify the air you are taking in but that air has to come from somewhere, the dehumidifier would not be able to keep up with the fans. I got some HEPA filters on the way but I know we need to eventually get our humidity below 50% or we will constantly be battling mildew. Constructing a pre-filtration room outside is in the realm of possibility. I like building things. Let me know what you think.

 

[Tweaktion]

ohk so instead of running a dehumidifier till it actually works (would only take time)
you'll just redesign it all? if your res is inside the grow could move outside?
color of your pots may make a difference. picture would be like way to nice.

 

[Gadfly]

Sierra Natural Science SNS-244 Best for Powder Mold

Additional fans, a/c, and dehumidifiers will help bring down the rh. You should get on top of this before you go from powder mildew to mold in your flowers. If you're constantly circulating air at 60% rh then you're chasing your tail. You want to control the environment, not simply run outside air through. The intake fan should have a lower cfm than the exhaust so you can create negative pressure and allow for greater control.

 

[kershaw]

, The intake fan goes to two rooms, the exhaust fan is in the flower room, so there should be some negative pressure. So you think that with the air in the room changing every 45 seconds that putting a large dehumidifier in there will still make a difference? OR are you saying just down the intake and run a dehumidifier? The main reason we have so much air flow is to increase the air for the plants instead of buying co2. I have a hard time believing that the humidity will actually drop with the dehumidifier running when the air is changing that fast. I guess we can always try it though.

 

[Gadfly]

If I understand correctly, you're using your bloom room to exhaust everything. I would exhaust each room separately away from your intake source, and go w a passive intake if possible. Dehumidifiers are one tool in the fight to control rh. I've been in rooms that used several dehumidifiers, a/c, oscillating fans galore, and humidity was still a constant fight. It's just something you gotta stay on top of for the bloom room.

 

[trichomes]

If you put the output from the dehumidifier into your fresh air intake, that would constantly put lower humidity air into your area. I have no idea if this is the best solution but I think it would definitely lower the %/level you run w/out it. That's my first thought. Best of luck, I watch for your solution idea.

 

[JJ Bones]

20ft by 20ft, what size ceiling? 1270 cfm seems small for 3200 cubic feet of space?

Dehumidifiers are worth the investment, hands down. When you are gardening in large spaces these things are essential corners cut is only hurting the yield.

I would also recommend a sulfur vaporizer for each room as extra security. Hopefully you're running CO2 as well?

 

[94xjjohn]

I air condition, dehumidify, and carbon filter. To blow it all away would be madness. You have NO control with fast flow through. Change that and you'll be better off. Control and keep!

 

[coolboy]

"If you put the output from the dehumidifier into your fresh air intake, that would constantly put lower humidity air into your area. I have no idea if this is the best solution but I think it would definitely lower the %/level you run w/out it. That's my first thought. Best of luck, I watch for your solution idea."

This sounds a great solution, so dehumidifier is not avoidable