Humidity Help

Man I'm so lost. I'm gonna explain my setup and maybe someone can help me out, cause I really dont know.

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This is my little setup. Veg side on the left (2 x 5ish) flower on the right (4 x 6ish). The flower side is exhausted by a 6" canfan, which is exhausted outside.

Also theres a 4" duct fan blowing from flower to veg. Theres a 6" duct fan blowing from veg to flower. Now during the winter theres another window I'd pop open everything would stay cool and humidity wasnt a problem, even during rain.

Now its 75 outside and I cant just use the window. So I hooked up a dual hose portable ac. Its exhausted on the same window the canfan is.

Temps are no problem. I mean it keeps it icy cold. But the humidity hasnt been below 70% in over a week. Found a few spots of PM and I've accepted ima have to crop a few of these plants until I get this figured out.

But I need to get it figured out. Why wont the humidity go down?? I've tried running my dehuy, ran it all night last night, along with the ac, 84% rh in the closet this morning. The ac/dehuy are in the bathroom the closet is in. I'm stumped. I've tried every combination of the ac hoses, intake hooked to outside, not hooked up. No difference. Even turned on the house ac to try to lower it. After 6 hours of it being on I'm sitting at 70%..

Any advice? I'm ready to toss in the towel, too much fucking stress right now. I just dont understand why the humidity won't fucking go down...

Thanks for any help.

Maybe the fans, and now ac is putting negative pressure on the house pulling the moisture in from outside? I really dont know.

All I know is going from using a window to an ac to cool my grow has fucked me up royaly.

Man but theres no way ^ that's right. I've been running the canfan, and both ducts fans for almost 4 years. Well the canfan used to be an ipower but that's whatever.

I just dont get why the humidity doesnt go down during lights on. Yeah I've had high humidity after the dark period but almost never higher than 60%. During lights on it's usually mid 40s or lower. Dont know what's going on right now.

I would get a second humidity meter... If temps come down, so would humidity.

ANC said:

I would get a second humidity meter... If temps come down, so would humidity.

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Man have 3. Flower room reads 70%, veg is 67%. Third is without a battery right now.

Battery in the third one reads 71% on start up in same location as the other on flower side. Dont know if itd adjust any or not.

Temps are reading 70 across the board. These are under canopy readings, but also where I've been taking reading forever. Its 6-8 degrees higher above the canopy.

Get a dehumidifier or at least put your can fan on a humidity controller. You can't flower like that, it will turn bad for sure.

I've never used a portable. Hope you get it sorted.

https://www.dudegrows.com/convert-portable-air-conditioner-single-dual-hose-design/

https://www.rollitup.org/t/mocked-up-grow-room-for-dual-hose-a-c-think-this-will-work.915138/

No hot or cold showers! (steam - moisture) lol

macsnax said:

Get a dehumidifier or at least put your can fan on a humidity controller. You can't flower like that, it will turn bad for sure.

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It's already turned bad unfortunately. Started this thread to try and stop the bleeding really. Prolly a day or 2 from having to chop the entire room.

Canfan runs 24/7. Been running the dehuy during lights off due to electrical capacities, but it's like it doesnt even do anything. Usually you can tell the dehuy has been going, but was at 84% this morning on flower side. Dont remember veg side but it wasnt any better.

Maybe it has something with the canfan and ac exhaust being on the same window? Wouldn't think it would matter but what do I know. I've checked every point of the ac with the fan on and off and dont notice any difference in fan speed/air leaks from anywhere on the ac.

Man it's just crazy, here I am after buying this ac, like my shit bout to be over the top. Should have total environmental control, which I've never had, always relied on the central ac. And now im about to shut this shit down, man was I wrong.

TintEastwood said:

I've never used a portable. Hope you get it sorted.

https://www.dudegrows.com/convert-portable-air-conditioner-single-dual-hose-design/

https://www.rollitup.org/t/mocked-up-grow-room-for-dual-hose-a-c-think-this-will-work.915138/

No hot or cold showers! (steam - moisture) lol

Click to expand...

I didn't want to but it was my only option. And its even slightly risky. Landlord walkes by the window its hooked up to and hes gonna be like wtf is that, lol. Def no bathing in this bathroom. I've got the shower filled up with my water containers.

Feel like my setup would work if I was rocking something similar to the design in the thread. Unfortunately I can't do anything like that in this closet.

And I guess I need to get that intake hose hooked back up to the wall, huh. I pulled it off thinking its pulling moisture from the canfan. Been running in fucking circles for days now

You've got something fugged up. If this happened when you started using the ac, what else changed at that time? AC takes moisture out of the air. So your humidifier is working over time? Or you're in a humid climate?

macsnax said:

You've got something fugged up. If this happened when you started using the ac, what else changed at that time? AC takes moisture out of the air. So your humidifier is working over time? Or you're in a humid climate?

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Yes def started happening when I started using the ac. Central heat turned off, ac installed, and I quit opening and closing a window on a daily basis. Nothing else has changed. Havent used a humidifier for a couple years, used to need one in the winter. Not really a humid climate, has been raining the past 2 days but usually it's pretty low.

Idk it's almost like the air isnt moving or something, idk if that makes sense. Maybe to much negative pressure on this room? But there was no difference when the intake was hooked up to outside which should have relieved some of the pressure if there was any. Dunno why I'm hooked on negative pressure either.

Got a few things I'm gonna change tomorrow and see what happens. Really just grasping at straws at this point. Idk. I'm going to bed for now. Appreciate the replys.

You need to have an air inlet to exhaust at the rate you want too. Like you've been noticing that the air isn't moving, its probably because you don't have an inlet and outlet. Try opening a house window and keeping the bathroom door open. Open a house window other than the bathroom window. I would take your portable AC out. Only control temps with central air. As air cools RH goes UP! So by keeping it so cool you're fighting the RH.

1. Open house window & create air pathway.
2. Stack exhaust fans if lacking pressure.
3. Try cutting portable AC off.

The easiest most effective way to control RH is exhausting. If your outside climate is dry, exhausting is the best way. If your outside climate is humid, then its only going to be dehuey..

I've stacked 400cfm fans for the exact same reason you might need too, I've also used them in series when filters get tight. They seem to pull harder that way, not sure if its double though. Not any faster, just stronger. If you're having to draw air from one side of your house through and pumped out the bathroom (which is what I recommend if you have less than 70%RH outside climate) you'll need a decent suction, and a reason to stack fans. Also if the breeze is blowing opposite to your suction direction you'll need greater suction then too. Stacking fans seems to do it for me.

I'd also put both veg fans pushing into your bloom to create positive pressure to help it exhaust easier as well.

AC will probably pull no more than 20% of RH out of the air.

RH if 70 is bearable if you also have temps of about 80, provided you have super good air exchange.

ChiefRunningPhist said:

You need to have an air inlet to exhaust at the rate you want too. Like you've been noticing that the air isn't moving, its probably because you don't have an inlet and outlet. Try opening a house window and keeping the bathroom door open. Open a house window other than the bathroom window. I would take your portable AC out. Only control temps with central air. As air cools RH goes UP! So by keeping it so cool you're fighting the RH.

1. Open house window & create air pathway.
2. Stack exhaust fans if lacking pressure.
3. Try cutting portable AC off.

The easiest most effective way to control RH is exhausting. If your outside climate is dry, exhausting is the best way. If your outside climate is humid, then its only going to be dehuey..

I've stacked 400cfm fans for the exact same reason you might need too, I've also used them in series when filters get tight. They seem to pull harder that way, not sure if its double though. Not any faster, just stronger. If you're having to draw air from one side of your house through and pumped out the bathroom (which is what I recommend if you have less than 70%RH outside climate) you'll need a decent suction, and a reason to stack fans. Also if the breeze is blowing opposite to your suction direction you'll need greater suction then too. Stacking fans seems to do it for me.

I'd also put both veg fans pushing into your bloom to create positive pressure to help it exhaust easier as well.

Click to expand...

Cant leave the bathroom door open because of fucking cats. This was my reasoning for getting a dual hose ac. Thinking its adding air to the room should help exhaust better, but def not.

Man I'd love to just use the central air, but not really possible until later in summer. Isnt getting above 75ish out, the ac won't run but 2-3 times a day, and that bathroom only has 1 register.

What exactly do you mean by stacking fans?

Finally done raining and humidity is down to 30% outside. Lights are out so, I popped the window in the room open and turned the ac off. Humidity is dropping already, 1.5 hours until lights on I'll see what it is.

ANC said:

AC will probably pull no more than 20% of RH out of the air.

RH if 70 is bearable if you also have temps of about 80, provided you have super good air exchange.

Click to expand...

I wish 70 was working. I mean my fan game isnt lacking, both exhaust and air movement, but shits not good right now. Not terrible but working on getting there if this isnt curbed soon. Canopy temps run about 78-80 and below canopy 68-70.

Man I dont want to jinx anything but I think I got it. Humidity was at 57%, lowest I've seen in 9 days. Dropped 18% in about 15 mins.

Pretty sure I goofed up the board that everything exhausts through. I made some jank ass vent type deal for tye ac to hook up to, for some unknown reason, I'm sure I had some fucked up idea going on in my head. So, I just remade that board with a new air take off, and put the ac directly on that board, and man you can feel a difference in the air coming outta that window.

Grower899 said:

Man I dont want to jinx anything but I think I got it. Humidity was at 57%, lowest I've seen in 9 days. Dropped 18% in about 15 mins.

Pretty sure I goofed up the board that everything exhausts through. I made some jank ass vent type deal for tye ac to hook up to, for some unknown reason, I'm sure I had some fucked up idea going on in my head. So, I just remade that board with a new air take off, and put the ac directly on that board, and man you can feel a difference in the air coming outta that window.

Click to expand...

Lol good work, glad you got it solved. When I say stacking fans I mean putting 2 in a row on the same line. I wouldn't worry about it though, as it seems you're good now.

Filter -> Fan -> 10ft flexible ducting -> fan -> boot register
(Normally I set the filter ontop of the tent but I'm tearing down and during drying I can't hook the clothes hangers on the cross bars with the filter can sitting on top so I just drop it down, the pillow is to avoid ripping the ducting and trying to avoid sharp 90° turns)


I crack my grow room window and suck the hot air from the top of the room or ceiling and pump it down through my register boot. I have a fan at the filter to help suction and a fan at the register boot to help push. I also crack the kitchen window to facilitate the flow. Now when breezes blow the grow room is less effected, it seems to still have negative pressure. I don't use central air or a heater (only space heaters) so the house ducting is free to exhaust through. With the grow room window cracked as I pump the hot grow ceiling air down and through the house, the grow room window is forced to push air in to replace the stuff Im pumping away and creates negative pressure so I don't have to worry about smell.

ANC said:

I would get a second humidity meter... If temps come down, so would humidity.

Click to expand...

No no no, actual as temp goes down the water capacity of air goes down and the same moisture creates more RH. A/C units dehumidify air as they cool, if your room naturally cools RH generally goes up at night as temp goes down. This is why dew develops in the morning on plants.

ChiefRunningPhist said:

Lol good work, glad you got it solved. When I say stacking fans I mean putting 2 in a row on the same line. I wouldn't worry about it though, as it seems you're good now.

Filter -> Fan -> 10ft flexible ducting -> fan -> boot register
(Normally I set the filter ontop of the tent but I'm tearing down and during drying I can't hook the clothes hangers on the cross bars with the filter can sitting on top so I just drop it down, the pillow is to avoid ripping the ducting and trying to avoid sharp 90° turns)
View attachment 4315456

I crack my grow room window and suck the hot air from the top of the room or ceiling and pump it down through my register boot. I have a fan at the filter to help suction and a fan at the register boot to help push. I also crack the kitchen window to facilitate the flow. Now when breezes blow the grow room is less effected, it seems to still have negative pressure. I don't use central air or a heater (only space heaters) so the house ducting is free to exhaust through. With the grow room window cracked as I pump the hot grow ceiling air down and through the house, the grow room window is forced to push air in to replace the stuff Im pumping away and creates negative pressure so I don't have to worry about smell.

Click to expand...

Ahh I gotcha. Yeah I'm exhausting out of a window and use the register for the central air as my intake. I did take the register cover off and man you can feel a difference in the amount of being pulled into the room. So honestly I'm not sure if my "vent" was even the issue.

Humidity is at 52% over halfway through lights off, that I can deal with. But idk if it's because I took the register cover off or because I turned the ac off over night and just ran the dehuy.