Grow tent dehumidification advice

Alienwidow

Well-Known Member
I also use a dehumidifier since with my portable A/C unit when run on dehumidifier, it doesnt have a temp control. It will just freeze out the room until your turn the dehumidifier off and turn the controls on the A/C back to regular A/C. I use both on those hot muggy days where the RH can jump up from 50 to 80% real quick. Using both units I can drop the RH 30% and cool the room in a matter of minutes.
56% in your tent isnt a bad number at all. Certainly if you have a lot of good air circulation and movement in your tent.
Damn, 56% isnt that good. Ive seen bud rot indoors at 60%. I didn't read the whole post but id take more dehumidifiers and a little heat late in flower, than low heat and high rh. Home depot has a 70 pt for 250. Whats your harvest worth? Actually im going to go get another one i think.
 

ligrow

Well-Known Member
I also use a dehumidifier since with my portable A/C unit when run on dehumidifier, it doesnt have a temp control. It will just freeze out the room until your turn the dehumidifier off and turn the controls on the A/C back to regular A/C. I use both on those hot muggy days where the RH can jump up from 50 to 80% real quick. Using both units I can drop the RH 30% and cool the room in a matter of minutes.
56% in your tent isnt a bad number at all. Certainly if you have a lot of good air circulation and movement in your tent.
I'm not sure I understand what you mean or not..
Are you saying that you use one portable AC with dehu function, and another dehu at the same time? I thought you only have a portable cooling and control RH at the same time, it's not efficient to run Dehu and AC at the same time. Kind of confused right now lol...
So...As window AC that I am using can cool the room well. Do u think I should just add dehu bring down RH? Should I place it in the tent or in the room? After couple days observation, RH cannot be control just use window AC. RH raise to over 70% again. They are about a month after flip. Still Looking for some solution to fix this problem
 

ligrow

Well-Known Member
Damn, 56% isnt that good. Ive seen bud rot indoors at 60%. I didn't read the whole post but id take more dehumidifiers and a little heat late in flower, than low heat and high rh. Home depot has a 70 pt for 250. Whats your harvest worth? Actually im going to go get another one i think.
Thanks for stopping by.
Sorry my English is not good.
Do u think I should add dehu in the tent when AC running? A little heat during late flowering is fine? I thought temp should be even lower in last few week. I have Dehu right now, but haven't use it yet. Looking for some way to fix this problem in most efficient way.
 

Alienwidow

Well-Known Member
Thanks for stopping by.
Sorry my English is not good.
Do u think I should add dehu in the tent when AC running? A little heat during late flowering is fine? I thought temp should be even lower in last few week. I have Dehu right now, but haven't use it yet. Looking for some way to fix this problem in most efficient way.
Ok bud, i checked it out. Sounds like you have one window unit ac cooling the room / tent fresh air intake. Thats where id fix the problem. Get another one in another window if you can. Or get a bigger one. Double it up, run it over the door to inside the house. Whatever. That'll cool the tent via freshair intake through the room? Y/N? And then you can run the dehu and not worry about heat. You could test it to see if you need it in tthe tent or not. It may keep the rh down in the tent even if its just in the room.
 

ligrow

Well-Known Member
Ok bud, i checked it out. Sounds like you have one window unit ac cooling the room / tent fresh air intake. Thats where id fix the problem. Get another one in another window if you can. Or get a bigger one. Double it up, run it over the door to inside the house. Whatever. That'll cool the tent via freshair intake through the room? Y/N? And then you can run the dehu and not worry about heat. You could test it to see if you need it in tthe tent or not. It may keep the rh down in the tent even if its just in the room.
appreciate for the feedback again.
I dont have enough eletricity to run another window AC in the room, and I have no ability to make any wire from box.
right now my AC can cool the tent well, and I havent set to lowest temp on AC. Do you think I need another you to cover it up?
If really need to, I might get a bigger one.

Im not in states, Im not sure the number you mentioned on Dehu.
I have small Dehu it shows 1,85 L/kWh dehu ability: 9L/D
I test it with meter, only use less than 120w. I believed its a very small one.
I tried to put Dehu in the room, It didnt do really well, after a hour runing, only bring down RH by 7%
Now I set it into grow tent to see how it work.

When I setup up Dehu, I turn off the fan in the tent.
I found RH is lower by the time. down to 56% with Dehu.
As soon as I turn on the fan in the tent. RH raise to 60%

I have my intake duct hook on A/C to get the coolest air direct into the tent.
I could be temp different inside and outside of the duct, make lots of water drop on duct.
Do you think this might be where moisture come from?
 

HydroRed

Well-Known Member
Honestly the only way around your humidity issue is to use a dehumidifier in the room that your tent is in. You will need to bump up your A/C size to compensate for the extra heat coming from the dehumidifier at this point. I use both, but I have a A/C unit that is big enough to handle any heat I may encounter from dehumidifier etc. My A/C unit has a built it dehumidifier but when the dehuidifier is on, it doesnt blow hot air like a regular dehumidifier does. Mine blows cold air and there isnt a temp gauge when run in this mode. This is why I use the dehumidifier. So I have total control over my rooms environments both RH and temp. My room doesnt budge above 79* 55%RH in the hottest & humid of days. I run my rooms a bit different than you though too. I use outside air to cool my room in the winter when I run my (2) 1K watt HPS, and I use a closed room in the summer with my A/C and I use LED lights which run far cooler than my HPS. My A/C doesnt have to work too hard and I dont have to vent my lights in the summer either. I use the outside air/temperatures in my favor year round. Its about whatever works best for your room and situation. My ventilation setup for summer/winter each work very good for me and they save me a lot of $ on energy consumption & losses.
 

Alienwidow

Well-Known Member
appreciate for the feedback again.
I dont have enough eletricity to run another window AC in the room, and I have no ability to make any wire from box.
right now my AC can cool the tent well, and I havent set to lowest temp on AC. Do you think I need another you to cover it up?
If really need to, I might get a bigger one.

Im not in states, Im not sure the number you mentioned on Dehu.
I have small Dehu it shows 1,85 L/kWh dehu ability: 9L/D
I test it with meter, only use less than 120w. I believed its a very small one.
I tried to put Dehu in the room, It didnt do really well, after a hour runing, only bring down RH by 7%
Now I set it into grow tent to see how it work.

When I setup up Dehu, I turn off the fan in the tent.
I found RH is lower by the time. down to 56% with Dehu.
As soon as I turn on the fan in the tent. RH raise to 60%

I have my intake duct hook on A/C to get the coolest air direct into the tent.
I could be temp different inside and outside of the duct, make lots of water drop on duct.
Do you think this might be where moisture come from?
That moisture is from having such a high rh in the room it's basically falling out of the air and onto things. If you are maxed out on your availible amps or electricity, find another place in your house thats on a different power breaker circut, and run an extention cord from a different room. Extention cords should be good to 15amps. Dehu usually runs at about 6 amps.
 

ligrow

Well-Known Member
@HydroRed Yes Im using Dehi right now.
Its a smalll unit not bring to much heat.
I put it in the tent I bring down RH to low 50%
The problem is water tank of Dehu is too small.
It fill up and stop running less than 6 hrs.
try do setup some tube drain out water to keep Dehu running all the time.
but it still fill water in the tank that is attach on Dehu.

I use outside air to cook the room too. I usually just give up in summer.
only veg, and wait till Oct. to flip.
This is my first time battling with the heat in flowering stage.
Im sure I will oversize AC unit when Im doing some equipment upgrade.
Also would like to try tent exhaust with thermostat controlled outlet to save some money on electricity

You mentioned you are using portable A/C with Dehu function. Is that all the A/C with dehu running it with less heat than regular Duhu?

single hose portable A/C question for my another room
Do you leave a intake for that room as there is only one hose for A/C?
I kind of sealed up the door leak for that room to keep cold air in there.
Not sure if it that way to using single hose A/C

once again thank for the feedback

@Alienwidow Thanks for your feedback.
Im using small Dehu now can bring down RH to low 50%. Temp highest 82.
I will wait couple days to see how they work.
If Dehu can not bring down RH under 50%, should I be more concern about it?
The one Im using only use 1 amp. I should be good unless i need a bigger unit of Dehu
 

HydroRed

Well-Known Member
The dehu function on my A/C unit doesnt blow any hot air at all. It blows ice cold conditioned air, but the catch to that is I have no control over the temp when it is run on this setting.The heat from the dehu built into my A/C unit blows from the single hot exhaust tube that gets vented outside. It kills the humidity but just gets the room too cold since there is no temp control in this mode. Thats why I run a seperate dehu. The one built into the ac unit works as a backup incase the humidity ever gets higher than my dehu unit can handle or if the temps get too high from the heat of the stand alone dehu unit (which neither has happened yet).

For your second question, I do have multiple in/out I have for my room to leave me plenty of options. If they arent currently being used, they get capped off but are there if I ever need them. I have a carbon filter and an inline 680cfm fan I use when the weather demands it. Basically, the seasons dictate how my room ventilation is set up. Hope this makes sense.

Got a picture of the dehumidifier you are using? I might be able to help you come up with something safe & effective for it to drain into a larger container.
 

ligrow

Well-Known Member
The dehu function on my A/C unit doesnt blow any hot air at all. It blows ice cold conditioned air, but the catch to that is I have no control over the temp when it is run on this setting.The heat from the dehu built into my A/C unit blows from the single hot exhaust tube that gets vented outside. It kills the humidity but just gets the room too cold since there is no temp control in this mode. Thats why I run a seperate dehu. The one built into the ac unit works as a backup incase the humidity ever gets higher than my dehu unit can handle or if the temps get too high from the heat of the stand alone dehu unit (which neither has happened yet).

For your second question, I do have multiple in/out I have for my room to leave me plenty of options. If they arent currently being used, they get capped off but are there if I ever need them. I have a carbon filter and an inline 680cfm fan I use when the weather demands it. Basically, the seasons dictate how my room ventilation is set up. Hope this makes sense.

Got a picture of the dehumidifier you are using? I might be able to help you come up with something safe & effective for it to drain into a larger container.
This is my current setup for Dehu, Can only get RH to low 50% right now.
Here are some pics of my tubing, but it just wont drain from there.
1234.jpg
tubing
123.jpg
small box I set for drain
image.jpeg
 

ligrow

Well-Known Member
I set my Dehu higher make sure water drain out from tubing out of the tent.
I can have Dehu running 24/7 without any off time when water tank is full.
RH in the tent around 50-60% Temp would go high to 84 if I dont turn up A/C
Probably need bigger unit Dehu to lower the RH, but Do I really need to bring RH low like 40% in late flowering stage?
If having bigger Dehu then Im afraid the A/C wont be big enough to cool the tent.
its not even really hot recently, so still long battle with heat this summer
 
The way you have your tent exhausting into the room that you are cooling is wasteful of the energy you are using and isnt working in your favor.
If you can manage to rearrange your inlets to pull air from outside to cool the hps lights, then exhaust that outside, your A/C unit will be more effective and you wont be constantly heating the room you are using to cool your tent with.
Here is a quick example of what I mean:
View attachment 3702748

This should help you get your environment in check and your RH down before running a dehumidifier. The A/C unit will naturally pull humidity from the air once you have everything set up properly and the ac isnt trying to cool "new air" all the time. Hope this helps.
The way you have your tent exhausting into the room that you are cooling is wasteful of the energy you are using and isnt working in your favor.
If you can manage to rearrange your inlets to pull air from outside to cool the hps lights, then exhaust that outside, your A/C unit will be more effective and you wont be constantly heating the room you are using to cool your tent with.
Here is a quick example of what I mean:
View attachment 3702748

This should help you get your environment in check and your RH down before running a dehumidifier. The A/C unit will naturally pull humidity from the air once you have everything set up properly and the ac isnt trying to cool "new air" all the time. Hope this helps.
showed

Hey Red, great advise and diagram, got a question though...
what if your running a carbon filter?
I have a 6" filter on my light being pulled out by an 6"exhaust , that's plenty strong, which blows under my house, helps keep the pipes from freezing in the winter, but probably caused problems in the summer. ( different issue)
My question is do I need another exhaust fan hooked up?
I just open the side vents on my tent to pull in air at this point, but humidity is an issue during the summer and the a.c can't keep up with humidity. It's a 5X5X8 with a 1000 watt HPS..
 
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HydroRed

Well-Known Member
showed

Hey Red, great advise and diagram, got a question though...
what if your running a carbon filter?
I have a 6" filter on my light being pulled out by an 6"exhaust , that's plenty strong, which blows under my house, helps keep the pipes from freezing in the winter, but probably caused problems in the summer. ( different issue)
My question is do I need another exhaust fan hooked up?
I just open the side vents on my tent to pull in air at this point, but humidity is an issue during the summer and the a.c can't keep up with humidity. It's a 5X5X8 with a 1000 watt HPS..
The humidity has to be controlled in the room that you are pulling air from into the tent. The exchange is likely so fast in a 5x5, theres no controlling it "in tent".
 
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The humidity has to be controlled in the room that you are pulling air from into the tent. The exchange is likely so fast in a 5x5, theres no controlling it "in tent".
Got ya...I think lol so my best bet would be to get a dehumidifier for the room the tents in? Which is maybe 11X11
I should add the house has heating and cooling but in the hottest months I still have to run a small window unit, but my humidity gets to high, I haven't had a problem yet, but feel it's only a matter of time. The window unit has a dehumidifier, but it raises the RH.....it is older, and not real big.
I was thinking of switching my exhaust to a window during the summer, not sure if it make a difference in the room, but it should help cost a little, blowing not air under the house during summer has to warm the house some right?
so with a 11X11 room with this set-up, would a 70 pint Dehumidifier be big enough or two big heat wise? Also I'm guess a larger A.C. With a built-in DH wouldn't work huh?
Oh...I might hit 75 TH during the summer, maybe 80 when its bad, but lots of moving air 24/7.....thanks bro ✌
 

HydroRed

Well-Known Member
I would think that the ac unit would naturally work as a dehu too since it pulls water from the air and condensates on the unit and drips outside. I use a 35 pint in my room that is about the same size and it works perfectly during lights off (I use the drain option on mine now since the tray filled up and shut off the dehu within a 12 hr period or less). In the summer, I use just an ac unit in a sealed room no dehu or anything and the ac unit keeps the RH in check. My ac unit is old as hell too.
 

ThaMagnificent

Well-Known Member
I would think that the ac unit would naturally work as a dehu too since it pulls water from the air and condensates on the unit and drips outside. I use a 35 pint in my room that is about the same size and it works perfectly during lights off (I use the drain option on mine now since the tray filled up and shut off the dehu within a 12 hr period or less). In the summer, I use just an ac unit in a sealed room no dehu or anything and the ac unit keeps the RH in check. My ac unit is old as hell too.
I'm guessing that thermostat has to be in the grow?
 
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