Serious humidity problems...

Im completley baffled by this, nothing I do seems to work. Im 5 weeks into flowering and when the lights are out my humidity ranges from %50-%80. I know thats bad, no matter what I do I cant lower it. I just checked the room and its at %99! Im going to get rot for sure.

The room is 12x16x7.

I have an 840 CFM fan with a charcoal filter that kicks on to exhaust when the humidity gets above %50 (it doesnt seem to do anything, it creates a huge vaccum in the room so I know its working).

240 cfm intake on bottom of the room.

I only added these fans to try and lower the humidity, I have a 3 ton mini split that is cooling the room fine.

But the AC de humidifies, and I also have two -70 pint de humidifiers in there that kick on when the lights go out, they work, theyre pulling tons of water, but I still cant lower the room humidity at all. Even when I have everything going at once. Does anyone have any suggestions what so ever? Im completley out of ideas. I have the floor lined with plastic and going up a foot or two on the walls, 1 person said thats bad cause it retains water?

what is the temp difference when lights go out? could be condensation forming on your gauge causing a false reading. this would happen if the temps take a fast drop..

basically if there is humidity in the air your going to have a hard time getting rid of it, just make sure theres a fan on the plants at all times to help dry off the "dew" that may be forming on them. only other option is to completely seal the room off from outside air and run your dehumidifiers.

you can try and rig up a heat source to come on and keep the room at a set temp, this will remove the drop temps during the night time hours thus you wont build condensation.

ZerocoolSmith said:

Im completley baffled by this, nothing I do seems to work. Im 5 weeks into flowering and when the lights are out my humidity ranges from %50-%80. I know thats bad, no matter what I do I cant lower it. I just checked the room and its at %99! Im going to get rot for sure.

The room is 12x16x7.

I have an 840 CFM fan with a charcoal filter that kicks on to exhaust when the humidity gets above %50 (it doesnt seem to do anything, it creates a huge vaccum in the room so I know its working).

240 cfm intake on bottom of the room.

I only added these fans to try and lower the humidity, I have a 3 ton mini split that is cooling the room fine.

But the AC de humidifies, and I also have two -70 pint de humidifiers in there that kick on when the lights go out, they work, theyre pulling tons of water, but I still cant lower the room humidity at all. Even when I have everything going at once. Does anyone have any suggestions what so ever? Im completley out of ideas. I have the floor lined with plastic and going up a foot or two on the walls, 1 person said thats bad cause it retains water?

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How long is it taking for each dehumidifer to fill?

I have to agree with the above, it seems your sensor is giving you false readings. Verify it is in a location that is in good air movement and get another small humidistat or 2 and place them around the room and get a "profile" of what is happening. Seems to me if you have enough equipment. Is the air coming through the intake raw outside air? If so, try not using it in a forced sense and let it operate passively for a spell.
Hope this helps M8.

Peace and Great Grows

Asmallvoice

I have 2 humidistats, the de humidifiers have sensors, and the exhaust fan is on a sensor, they all read in the same ball park. Its getting really high with the lights off.

The temp differential is 82-62 degrees when the lights are on and off. Usually lights on its 75-79 degrees and the last hour or two itll raise to 82 sometimes. Lights off is always around 62 which I know is cold but unless I manually change the AC everytime theres nothing I can do. Setting it on auto doesnt work cause it has a heat pump in it.

I orginially had the room sealed and 2 de humidifiers, wasnt cutting it.
With the intake fan, I actually have it turned off and it just pulls air though the hole so its passive.

Someone else just told me that wet air is heavier and rests at the bottom of the room. So Now I have my fans blowing up at the canopy instead of level with them, I turned the passive intake air fan at the bottom around to blow air out of the bottom (wouldnt hurt to get cold air out of there anyways when the lights are off). Im going to lower my big exhaust fan so its on the floor, right now the filter is level with the canopy. Im trying so many things and nothing seems to be working.

Take a step back and take a logical approach. Also, don't listen to someone or some guy unless it makes sense. I know your getting desperate but moving fans down low and removing plastic aren't going to solve the situation.

Humidity that we talk about is RH, relative humidity. So think about that. And think about your massive temp drop which would cause a humidity spike....

So why is your temp getting so low at lights off again?
What temp do you have your minisplit set at?
Where is your intake fan getting its air?
What is the temp from the area the intake fan is getting its air?

Before you installed the fans was it sealed lights out, and 2 dehumidifiers? I would think that should handle the humidity...not saying it will though.

- Jiji

jijiandfarmgang said:

So why is your temp getting so low at lights off again?
What temp do you have your minisplit set at?
Where is your intake fan getting its air?
What is the temp from the area the intake fan is getting its air?

Before you installed the fans was it sealed lights out, and 2 dehumidifiers? I would think that should handle the humidity...not saying it will though.

So why is your temp getting so low at lights off again?
What temp do you have your minisplit set at?
Where is your intake fan getting its air?
What is the temp from the area the intake fan is getting its air?

Before you installed the fans was it sealed lights out, and 2 dehumidifiers? I would think that should handle the humidity...not saying it will though.

- Jiji

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Its getting so low during lights off because the AC is set at 69 degrees on cool mode, if its set any higher then 69 itll get above 82 degrees sometimes during lights on. When lights turn off, the AC is still set to 69 degrees, so it gets down to 62 degrees normally. Sadly I cant put the AC on auto, it has a heat pump and when its on auto the heat pump kicks on out of nowhere and will raise it to 90 degrees. 69 degrees is the best medium I could find.

Intake fan is at the bottom of the room, below the AC. It was pulling in air thats 80 degrees and %40 RH. Doesnt seem to help much though.

Before the fans it was sealed and 2 de humidifiers werent cutting it. Very strange.

Lights on its pretty much 78 degrees, and %50 RH constantly.

Hmmm,

Well shit. lol

Most mini splits have a cool only function. Also, is it a DC inverter model? Most likely its really not helping that much setting it so low, it just kicks on a little earlier.

A little over 82 isn't ideal but it isn't a game changer, over 60 percent RH late in flower is. I'd try kicking it up a couple degrees and take notes.

How big is your intake? I would take the intake fan out, and make the intake twice as big as the exhaust fan and see what happens then.

70 pint dehumidifiers from box stores aren't that efficient and really don't work that well. Santa fe makes some nice ones and if you want to get serious pheonix makes some crazy ones....but they aren't cheap.

Your pulling in pretty dry air though.....a different fan setup may work.

- Jiji

Did a little search look up top ten things aboutair cconditioners states ac controls humidity better when it doesn't have to work as hard I have similar prob but on smaller scale if I dint run ac lower than desired temp on off on off but coming from them if your ac gets some rest not continuously running better control humidity and I'm sure u know raining outside 100 percent humidity might help someone searching this later

$1,200 and up on a de humidifier seems insane, but I get it might be the only option. Im gonna try 1 or 2 more things and see what happens. But I agree, higher temp lights on is better then really high humidity.

Is the air moving through the room so fast that the air or dehumidifier cant really have an effect

Kill the aircon when lights are off and run dehu only.

Turned off the AC, temp raised and humidity lowered. But I cant manually do that every day.

But im 90% sure I fixed the problem, its been fine all day. I should have mentioned this earilier but I didnt know it was an issue. The de humidifiers were raised, 1 was on a 55 gallon drum, to drain right into it. The other, on 5 gallon buckets and draining into another 5 gallon bucket. This was so I didnt have to empty the de humidifiers twice a day each cause I cant be there all the time.

I put the dehumidifiers floor level, I also used a feature on my AC called "follow me." That turns the ac remote into the sensor that controls the AC. I put the remote canopy level, the AC stopped making it so cold (it stays at 69 instead of going to 61-62 degrees now). The sensor on the ac head unit is high up in the room where its probably hotter so it wasnt turning off when it should.

Lights off my temp is now at a constant 68-69 degrees, and humidity with lights off is ranging from %38-%58. Whereas before it was 61 degrees and humiditiy was ranging from %50-%90.

If anyone can learn from my mistakes, put your dehumidifiers at floor level, wet air is heavier. Also the colder it is, the more condensation and wetness when lights are off.

Put the AC feed on a double pole contactor of appropriate ampacity equipped with a coil voltage compatible with your lighting controllers trigger. If your AC resumes proper operation at previous settings after a power outage, this will work. Test by tripping breaker, wait a few minutes and reset, if unit resumes operation this plan will work.

A decent condensate pump for your dehumidifiers is around 60 dollars. After you get it, you'll wonder how you lived without it.


- Jiji

SnapsProvolone said:

Put the AC feed on a double pole contactor of appropriate ampacity equipped with a coil voltage compatible with your lighting controllers trigger. If your AC resumes proper operation at previous settings after a power outage, this will work. Test by tripping breaker, wait a few minutes and reset, if unit resumes operation this plan will work.

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After I get the flux capacitor repaired Ill get that going


Thatas what theyre called, condensate pump. Ill for sure get one of those. Thanks for the replies

seems your sorted now...i was going to suggest setting the AC up on a timer that kicked on/off the same time your lights do. that would get rid of the huge temp drop and maybe cut down on the humidity.

as far as "wet air" being heavier, im not really sure i grasp that..usually the warmer air has a higher RH and warm air rises...but i may be wrong there im no physics major.

yeah did a quick google search and while in theory it sounds good humid air is actually lighter than dry air. I can see why you would think otherwise as it makes sense in theory (air with water in it must weigh more thus making it heavier) but its the opposite.

ZerocoolSmith said:

$1,200 and up on a de humidifier seems insane, but I get it might be the only option. Im gonna try 1 or 2 more things and see what happens. But I agree, higher temp lights on is better then really high humidity.

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I use them. They are insane. They remove an insane amount of water from the air. Which is what you want to do.

clayawesome said:

I use them. They are insane. They remove an insane amount of water from the air. Which is what you want to do.

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I love the Phoenix 200's. Buy 'em new and they last forever.