what do you do?

[Spaventa]

Need some help...What can I do to lower humidity in my growroom when its 70%rh outside?
I can't draw the intake from inside or my temps will rocket.
My intake and exhaust fans move around 500 cubic meters through the 3 cubic metre box per hour and the lights on humidity is o.k but during the dark, with lower temps and resulting condensation, it goes into the 90s
Ive been damn lucky not to lose my last harvest to bud rot - that happened last year growing chronic donkeydicks
Any help appreciated, as always

 

[big bang]

dehumidifier. get it at any major retailer.

 

[clowntown]

 

[Spaventa]

I'm surprised at both of these replies - don't you know that a dehumidifier won't work when your ventilating, as I am, with seperate inline exhaust and intake fans that draw air from and to outside of the property...I'm changing ALL the air in the room every 2.5 minutes which isn't long enough for the dehumidifier to get one hundreth of it through it...or are you both suggesting that I get one big enough to dehumidify the whole world? Serious responses only please.
btw - I was silly enough to think it might help myself and bought one and tried it about a year ago lol
I may have to draw dry air from inside the property and use aircon to combat the increase in temps...
bigbang - what A11 do you have? I grow the Genius pheno...

 

[PoppinFresh]

I'm surprised at both of these replies - don't you know that a dehumidifier won't work when your ventilating, as I am, with seperate inline exhaust and intake fans that draw air from and to outside of the property...I'm changing ALL the air in the room every 2.5 minutes which isn't long enough for the dehumidifier to get one hundreth of it through it...or are you both suggesting that I get one big enough to dehumidify the whole world? Serious responses only please.
btw - I was silly enough to think it might help myself and bought one and tried it about a year ago lol
I may have to draw dry air from inside the property and use aircon to combat the increase in temps...
bigbang - what A11 do you have? I grow the Genius pheno...

i'm a super noob and i probably shouldn't even be trying to answer. but i think i read in another thread or in watching urban grower clips, i understood that you don't have to move the air that much. or maybe you can rig something that can remove some of that humidity as the air is coming in that fast. in other words, either figure out how to take out the humidity as fast as air is coming in or move air much slower to give a dehumidifier some time to work.

does the air really have to be renewed that fast?

 

[Guest]

Serious responses only please?Should I dehumidify the world?No,you should quit being an asshole though.You have the correct answer but you find yourself too knowledgable to accept it.Dehumidifiers work to lower a rooms relative humidity.If you are constantly circulating 70% humid air through the room,the RH is 70%.Set a dehumidifier to 40%RH and it certainly will give you buckets of water brainiac..

 

[clowntown]

Spaventa, I'm so sorry my answer wasn't serious enough for you.

You need to build a real fast car? It needs to go real, real fast? But all you have to work with is a tin can and some rubber bands? Sealing the intake and air conditioning the room is too much? (A/C's are also dehumidifiers.)

Sorry, bro. Maybe you should start asking serious questions if you want serious responses.

 

[Spaventa]

If you are constantly circulating 70% humid air through the room,the RH is 70%.Set a dehumidifier to 40%RH and it certainly will give you buckets of water brainiac..

I suggest you think you comments through.
As I pointed out, I replace the air in the room every 2.5 minutes - this is the optimum ventilation requirement - it keeps temps under control, co2 levels high and nitrogen from building up but thats another chapter you should have read elsewhere..I don't just move the same air around.
The point is, a dehumidifier will not beable to lower the humidity of that volume of air at that rate. The humid air is being changed out of the room before the dehumidifier has time to dehumidify it - unless I bought one that uses more power than the rest of my grow combined.

 

[Spaventa]

Spaventa, I'm so sorry my answer wasn't serious enough for you.

You need to build a real fast car? It needs to go real, real fast? But all you have to work with is a tin can and some rubber bands? Sealing the room and air conditioning it is too much?

Sorry, bro. Maybe you should start asking serious questions if you want serious responses.

Dude, what planet are you on??? I'm gonna guess that your trying to say that Ive posed an impossible question in the pursuit of a "free lunch"...why?

I have a $4000 growroom and I spend more on nutes in a year than you have on your growroom - I know you punk from here and elsewhere so stop tagging this - on to other peoples worthless posts.

Look, I know there are growers on here, far more knowledgable than myself (thats why i posted my question) its just that you guys aren't them kay/ so go play and leave it for others.

 

[clowntown]

Wow a $4000 growroom. Wow expensive nutes.

Where do I know you from?

Edit: Actually, nevermind. You can troll yourself. Excuse me from this thread.

 

[Spaventa]

i'm a super noob and i probably shouldn't even be trying to answer. but i think i read in another thread or in watching urban grower clips, i understood that you don't have to move the air that much. or maybe you can rig something that can remove some of that humidity as the air is coming in that fast. in other words, either figure out how to take out the humidity as fast as air is coming in or move air much slower to give a dehumidifier some time to work.

does the air really have to be renewed that fast?

well so far, your the smartest guy to reply so thanks man
You clearly get it about the volume and rate of ventilation making the dehumidifier inefectual but you realy do want to ventilate as much as that if the situation requires it. I calculated my fan sizes based on intake temps, room size, lighting wattage and optimum exstract temp - Less ventilation would cause temps to rise above optimum, co2 to fall below 300ppm and humidity would be dangerously high with lights on and at saturation point during dark which would result in a pretty quick death as they drown because they can no longer transpire through the leaves...

 

[PoppinFresh]

aside from responders being a little rough, i have to agree with The American. you already know the answer. it would seem you've got to use that a/c just like you said and recirculate the air from within. i suppose you would have to do get another fan or rig the tubing to recirculate and maintain some exhaust. i figure at some point you'll have to refresh the air.

keep us updated tho. im still learning myself.

 

[Spaventa]

Lets not get confused, TheAmerican suggested I buy a dehumidifier. This is not the answer, If it was, my problem would have been solved 12mionths ago when I installed a very good one. If I'd applied any logic, I would have known it was not going to work but hey it comes in handy for my drying area...

The closest thing to an answer is the one I provided myself - using aircon and drawing my intake from inside the house (this still isn't recirculating though as your continuosly exhausting to outside. Also, there comes a point when my house will be drawing new damp air from outside to cope with me exhausting it at 390 cubic metres per hour...


Obviously, I came here knowing that it maybe the only solution but I don't walk around thinking I know it all so I came here to see if any of the realy clever, knowledgable guys could think of somthing.

 

[ItsGrowTime]

I have this same thing in my growroom since its heavily influenced by outside conditions. I just have a ton of ventilation (huge intake fan) and that seems to work pretty well. If your room is that heavily influenced by outside air (unsealed) I doubt a dehumidifier would make all that much of a difference. Big circulation is just as important as the humidity level.

 

[Spaventa]

itsgrowtime - totaly man, I took the guy in the growshops advice on that when I started. I have a 4" Vortice centifugal for my intake and a 6" Vortice centrifugal for my exhaust for a room box just 6ft x 4ft x 6ft(h) so I have great ventilation but even with addition air movers in there (2 x 9") you still run a risk of top rot as the they get dense enough at the end of flowering to keep light out and moisture in - a "microclimate" inside the bud provides a stable envoironment for bud rot. I doubt i'd get grey mould on the outside cos the ventilation takes care of the exsternal plant/bud but I know I'm skating on thin ice with things the way they are.
realy its a problem with our weather at the moment - its just not ideal for indoor growing but like someone said recently, it saves the guys having to water theyre outdoor plants
Last year it was temps I was fighting in the heatwave - this year its cool as fuck but damp, the solution ultimately is move to somwhere with better weather.
thanks for replying dude..and guys I'm sorry if I came across badly in the earlier part of the thread, I meant no ill, genuinely.

 

[manitu]

Hmmmm. You do NOT have to change the air each 3minutes during night. you could easily turn down the fan at night, just buy another fan-controller, hook the fan-control for daytime to your light-timer, and the controller for night-time to constant power.
This will give your AC or dehumidifier some time to work.

The only other way to solve this, without cashing out for a closed-loop system, is to cool your intake-air with a heat-exchanger-coil, then drain the condensed water from your intake-air-cooler.
If you find a car heater-core, (looks like a small radiator) you can put it inside your air intake and run ice-cold water through it. Now , the hotter, humid air will condense on the heater-core, and you must find a way to get the condensed water out of the intake. THE AIR WILL STILL HAVE THE SAME RH% , but it will be cooler , and hold less water, when you reheat the air, the RH% will fall big-time ( the air will pick up heat from your room , and the RH% wil fall, but much more so, if you reheat the air.)
Ofcourse, a real A/C unit, with cooling gas, instead of cold water, would work much better

Oh yeah, what is your nighttime temps? You could allso reduce humidity by raising the temps in the room.

.manitu

ps: edit: The man said sorry, Case Closed.

 

[Spaventa]

Thanks manitu but i tried what you suggest...and running a sealed room at night with lots of dehumidiying but even then it could not cope with the rate of transpiration from the plants. Ventilation has provided the best "MAX" reading on my hygrometer...the more ventilation, the lower the r/h, down to a minmum possible - that of the incomijng air.
So, I'm satified after exsperimentation over a year with heaters, dehumdifier, trying ights on at day, off at night - noe of it solved the problem.
I'm thinking about emptying a used carbon filter, and filling it with dishwasher salt and putting that on the end of the ducting to my intake fan. it will reach saturation point eventualy but I'll find out what volume of salt is needed to keep humidity optimal for 24 hours then make 2 so I can have one drying out in the house while i'm using the other.
It will be a while before i do another grow (jars are full and many)so I have nothing better to do than mess around with ideas in the growroom. I'm also gonna make some enclosures from chipboard and speaker baffling around my fans to cut down on noise.
Thanks man..

 

[Jack Crevalle]

or are you both suggesting that I get one big enough to dehumidify the whole world? Serious responses only please.
btw - I was silly enough to think it might help myself and bought one and tried it about a year ago lol

LOL

So why not pull air from inside the house during night cycle?

 

[Spaventa]

Well, venting as much as I am would soon deplete the "buffer" of dry air in my house (its no palace) then i'd be effectively pulling air in through gaps, vents, windows etc at the same rate that i'm exhausting - enough to turn my house cold and damp within a short time at which point I'd be no better off in the growroom and a lot worse off in the house.

What I didn't try that might work, is to draw air from inside the house at night, as you say, but only by humistat AND with the dehumidifier on in there, exstending the time between vents...so that 1 "housefull" of dry air would last all night keeping humidity realy low. Obviously, this would mean I'd have to run my lights during the day. SO fixing the humidity problem would give me more heat to deal with during light on but thats easy tpo fix with a few more air movers, and a bloody miracle
Thanks for all the responses everyone

 

[Jack Crevalle]

That was my next suggestion, use a timer and only vent for 15 minutes on and 30 off or whatever rate it takes for the small dehumidifiers to once again dry the room.
Sick!