Dehumidifiers and heat

whitewidow2

whitewidow2

Well-Known Member
Ok so i just bought myself a 12L dehumidifier for my flowering tent and it works as it should - happily collecting moisture from the air...

It brings humidity down to between 45-50% sitting in my grow tent with no lights or fans on

The problem is it brings the ambient temperature inside the tent up to 85F

Im worrried that when the lights go on this will push temperatures into an unaccaptable level for my plants... is there any way around this without using ac?

The setup goes filter>ducting>hood>ducting>up out the top of the tent>window with passive inlets for intake built into the tent
 
M

mydixiewrecked

New Member
whitewidow2 said:
Ok so i just bought myself a 12L dehumidifier for my flowering tent and it works as it should - happily collecting moisture from the air...

It brings humidity down to between 45-50% sitting in my grow tent with no lights or fans on

The problem is it brings the ambient temperature inside the tent up to 85F

Im worrried that when the lights go on this will push temperatures into an unaccaptable level for my plants... is there any way around this without using ac?

The setup goes filter>ducting>hood>ducting>up out the top of the tent>window with passive inlets for intake built into the tent
Click to expand...
i only run my dehu. when the lights are off, but I also have a very good a/c
 
whitewidow2

whitewidow2

Well-Known Member
im just experimenting just now to see what effect it has on temps and humidity without the lights on as its a brand new setup...

Need to get flowering sson though as my girls are 3 1/2 ft high in the veg tent at present!

Ive heard that night time is the problem where the humidity goes through the roof - i was just planning on running it constantly - does 45-50% seem ok for a dehumidifier, im in the uk climate
 
M

mydixiewrecked

New Member
whitewidow2 said:
im just experimenting just now to see what effect it has on temps and humidity without the lights on as its a brand new setup...

Need to get flowering sson though as my girls are 3 1/2 ft high in the veg tent at present!

Ive heard that night time is the problem where the humidity goes through the roof - i was just planning on running it constantly - does 45-50% seem ok for a dehumidifier, im in the uk climate
Click to expand...
yeah,during flowering 40-50% is perfect
 
whitewidow2

whitewidow2

Well-Known Member
Ok so if ive got perfect humidity... how do i get those temps down?

Do i have to add an ac unit to my grow tent

My hood is an air cooled one but from experience i know that when that light is on and the dehumidifier - the temps are going to soar
 
D

dark leaf

Well-Known Member
WOW, this is the thread I've been looking for. So I take it you guys just have two timers, one for lights and on for the dehuidifier? What is the RH in your guys areas like, mine is upwards of 75-85% so that damn dehumidifier pumps the heat out.
 
whitewidow2

whitewidow2

Well-Known Member
the problem is the dehumidifiers - whilst they lower the humidity - also put off heat and blow out warm air into the tent
 
whitewidow2

whitewidow2

Well-Known Member
If the dehumidifier is going to take the temps to 85F how do i get them down to 70-75F?

Do i HAVE to run air conditioning?
 
W Dragon

W Dragon

Well-Known Member
i've been wondering the same thing i'm in the uk aswell and gonna get a dehumidifier as my rh is nearly hitting 90 some days with the rain outside i've been in flower a couple of weeks and goona get 1 on the weekend but shifting the heat off it has had me concerned i'm in a 1.2x2.4x2 xxxl bud box with 2 air cooled 600s the only way i've been able to get around it mentally is to remove the carbon filter to help the exhaust, it's all theory so far but it's had me head scratching the last 2 wks
 
whitewidow2

whitewidow2

Well-Known Member
those mini splits look awesome - sadly not practical for where i stay currently

WDragon the dehumidifiers do put off plenty heat - mine has the ambient tent temp at 85F

I did my last grow without one and the day humidity was about 50% with the lights on so it makes me wonder if i need one - i only got one as i heard that they are a good idea to have - but it seems to come at a cost in terms of additional heat
 
W Dragon

W Dragon

Well-Known Member
whitewidow2 said:
those mini splits look awesome - sadly not practical for where i stay currently

WDragon the dehumidifiers do put off plenty heat - mine has the ambient tent temp at 85F

I did my last grow without one and the day humidity was about 50% with the lights on so it makes me wonder if i need one - i only got one as i heard that they are a good idea to have - but it seems to come at a cost in terms of additional heat
Click to expand...
i see the problem mate if you keep your rh down i'd say don't bother but i'm gonna have to get 1 i looked at them last night a couple of hours into lights on and my rh was 82 and i'm growing chronic and heavy duty fruity 2 large yeilding strains that come with warnings of mould and bud rot. i'd rather not use 1 but i've tried everything to get it down and come up wanting so i guess it's gonna be a plug it in and hope job for me the other prob i have is that it's not at my house it's in a large concrete shed with the lights on at night 7-7 so i won't be able to empty it every couple of hours at best i'll be able to do it once a day at 7pm, i'm off to check on them now and see what numbers i got there waiting for me also feeding them today and that pushes rh up slightly. bring winter back at least it stays cold then constantly lol
 
homebrewer

homebrewer

Well-Known Member
A good dehumidifier won't kick out a lot of heat and shouldn't affect your temps by more than a few degrees. Residential dehumidifiers are generally pretty junky and inefficient (which is what you have). I recently had to upgrade to a 200 pint dehumidifier (100L) that is commercial grade because my crappy little LG was pumping out HOT air 24/7. It was working and collecting water, but it raised my temps by 10* and only took out 5% humidity. If you don't want to spend $ on a better dehumidifier, look into some inline fans to vent your heat.
 
whitewidow2

whitewidow2

Well-Known Member
so do i really need a dehumidifier in my grow, my last grow turned out ok without one - i only got one to better my next one

thoughts - opinions?
 
W Dragon

W Dragon

Well-Known Member
if you can keep your rh down mate then no, but if it is high i'd get 1, well i'm going to got no choice after i just been up to water them the rh is now sitting at 86 it was 82 when i first walked in.
Homebrewer thanks for the suggestion mate i'll check the larger models out i'm also going to add a 4inch inline but i don't think it'll help as the rh outside is high and i have a 4inch in line for intake direct from outside and the difference between outside rh and inside is almost negligable
 
homebrewer

homebrewer

Well-Known Member
Humidity can be an issue when it comes to bud mold. One of my strains is fine with higher humidity, the other isn't and molds pretty easily due to the dense, resinous product. Check these guys out for commercial grade dehumidifiers:

http://www.sylvane.com/basement-dehumidifier.html

I'd recommend the $1000+ models. These may seem a little expensive, but they are extremely efficient, hardly ever run and keep humidity as low as you need it.
 
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