Dehumidifier Question(s)

I have a grow room that is about 8x4. I am only using about a 4x4 space to grow. I currently have a AC Infinity T6 that vents outside. Right now my temps are about 80 and my humidity is 70-75. I have a 4" fan blowing air in.

I am thinking about flower and the fact I may need a dehumidifier. The room is built in the basement. Here are my questions:

I currently have a huge 70 pint dehumidifier, would it better to run that an dehumidify the air that is being sucked into the room?

Is that dehumidifier overkill for a room that small? (even though it is rated for the rest of the basement)

If I decide to get an inkbird controller, would I put the probe inside the grow room to maintain humidity, or in the larger room to maintain humidity (if that makes sense)

I am ok now I think, but once flower starts obviously I need to get that humidity down


I dehumidify the lung room and have an exhaust venting from right next to the dehumidifier into the tent.

Also have the tent exhaust to outside the house.

Can usually keep the humidity in tent to what dehumidifier set to.


Hey brother welcome to the group. When I had a tent I had to hook my intake hose to my dehumidifier like this


It will raise the temp in your tent but it will control the humidity. I never got above 85*f and humidity stayed around 50%.

Temps will go up but you would rather have high temps and low humidity than the opposite.

I have a 5’ x 10 grow room now and have to do the same thing. I run my lights during the night and they sleep during the day. I can keep my RH below 45% with temps around 78 when lights out.
If I don’t run the dehumidifier, the RH will shoot up to 70%. But, I also run an rdwc system.
Keeping your plant pruned and thinned out will also help some.

Good luck! :+1:t2::v::sunglasses:



Do you have the dehumidifier inside your 5*10 room now that you not longer use a tent?

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I have my dehumidifier sitting outside in the adjacent room with a 6”hose attached to the top of the dehumidifier exhaust with a hose that runs down attaches to the wall.

I have two 6” vent intakes vents into my grow room. One is hook up to my dry box which has two 6” vent on that the other to my dehumidifier. Good luck. Ask if you have any other question.

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What is a dry box? Is it just a spot that your getting your intake air from?

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Yeah sorry about that,that’s where we dry our weed, or we can use it for a grow box. I’ve had it about two year but have only used it for drying. I’ll get some pics here in a min and show you what I’m talking about…:+1:t2::wink::sunglasses:

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Is there a way u can box off a smaller area where the intake vents are at. Block off say a 6x6 are and have the dehumid in that area keeping the area in check should help for intake rh purposes. I have issues keeping my room in check during summer time

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I could probably box off only like a 4 sqft area.

So I have the cloudline t6 connected to controller 67. According to the probe that come with it is says I’m at like 78 degrees and 74% rh.

I also have one of the Amazon thermometer/hygrometer combos that see on here and it reads about the same temp but like 65% RH.

Makes me wonder what one is accurate…

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Do u have the probe at canopy level or close to that’s where to get best reading I have a 4x7x8 room and have a infinity t9 with the 67 controller and still. My rh inhouse is pretty high due to running portable ac and window ac units because my central went bad winter had no issues in that room summer is all issues. But winter has furnace that runs and is a whole home dehumidifier also. Basements are a bit more of a pain because of rh issues. Make sure u have plenty of air movement to avoid wpm issues and try an keep rh down as low as possible especially in flower

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Yea typically in the winter here the furnace will kill all the humidity. I’ve moved both the probe and hygrometer around the tent all over ( canopy level, on the pots, above the lights etc) and the both are still anywhere between 7% and 10% different, but both have been consistent in their own readings. I know all of them are within a few percentage points accurate, I just don’t know which one to believe

Like I was saying, I have two intakes into my room. One on the left side of the room,

and one on the right side hooked up to my dry cabinet.

That cabinet has two vents on it like this, one on each side. The wood channels are used to allow air flow while keeping light out.

I left my dehumidifier on, on purpose to show the temp and RH

I have absolutely no problem adjust the temp, and or humidity. Works like a charm.

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That’s sweet! So I just built this room and it’s my first go. So right now I have 2 (6) inch inline fans blowing into my intake

That’s pretty low on the outer layer of drywall.

On the inside about 14" up I have the other side of the intake

My room is located by the stairs, do you think boxing off a section under the stairs and making that a lung area would have the same effect?

Sorry for the mess!

It’s that what your dehumidifier is connected to? I see the elbow and it looks like it goes into some sort of box and then your grow room?

What size room is your dehumidifier in?

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Here is what I currently have going on. This may help you visualize it a little better.

I run lights at night and they sleep during the day. 10 pm lights on, and 10 am lights off.
That gives me time to mess with them in the mornings and helps keep my temps regulated easier.

I have two 6” intake at the bottom and one 6” outlet at the top. My 6” exhaust fan brings air in the bottom and out through the top. The pictures on my journal may help.

Do you have electricity in your grow room?
Do you have an exhaust fan carbon filter (for smell if needed)? You need a way to exhaust the air if you don’t already have one.

My carbon filter is near my ceiling to pull hot air out, right above my light and near my drivers for my lights.

It would help. Not sure that is necessary. I’ve used a hose and just lay the end of the hose next to the intake and it will dehumidify the room. You may have to play with how close the hose is or how high the setting is on your dehumidifier. I have to monitor and adjust all the time but it’s better than having bud rot or mold issues due to high humidity. I grow in hydroponics so if I can control the humidity anybody can. :wink::+1:t2:

My dehumidifier is in a 12x11 room and it’s hooked up to one of my intakes into my grow room. Hope this helps. :+1:t2::v::sunglasses:

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I have a T6 mounted toward the ceiling.

It seems even if I run the T6 on 10 with both intake fans blowing, it still reads 75% humidity lol.

I definitely appreciate all of the help.

My last grow was in a 2*4 tent with 2 plants and it wasn’t an issue. This grow in this built room has 4 plants and it’s definitely much different!


I can guarantee if you hook the dehumidifier up like I have it, you will see a tremendous drop in humidity. Your temps will rise some but like I said, better to have higher temps than high humidity. Good luck! :+1:t2::v::sunglasses:

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Nice room and nice grow. :+1:
Just a thought on your humidity issues.

Are the walls to your room sealed at the top between the joists ?
Would certainly help if they’re not. And if already sealed up then rock on. :+1::grin:



Luckily I have the dehumidifier and some ductwork, so I am going to give it a go, as you can see I need to clean up the area. I was so excited to start growing after the build it’s a bit of a mess!


If you’re asking did I mount drywall to the ceiling joists…I did not. I honestly didn’t feel like hanging drywall above my head lol. However, the walls go all the way up to the joists so it is sealed in that regard. I also have insulated the exterior walls with Rockwool and then used the moisture resistant drywall.

Maybe after this go round I can seal off the ceiling. I’m always looking for ways to improve and automate my environment.



Ha ha. Can’t blame ya there. :joy:

FRP ( foam reinforced panels ) is a good moisture resistant option that’s light weight for when the time comes.
Not sure on pricing tho.
Happy growing. :+1:




Good to know!

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