Dehumidifier causing heat issues

psychadelibud

psychadelibud

Well-Known Member
I am 3 weeks into flower currently. My dehumidifier is putting out far too much heat inside my room. I have 4 1000 watt lights and running a 25,000 btu mini split which keeps the temps around 77-78 degrees... However, when my dehumidifier kicks on which it does often, it can raise the temps as high as 87 degrees and that is just too much heat. So lately I have had the dehumidifier set around 60 so that it does not kick on as often. But once I get to mid-end of flower, I'll need to bring that humidity on down to around 45%.

So I wanna get ahead of this problem quickly, before I'm making last minute decisions. I have thought of 2 different things so far...

1) build a cardboard enclosure around the top of the dehumidifier where it vents out the hot air, and vent it outside of the room. I have heard good and bad things about this... Basically some say they had success with it, some said they didn't. It's worth a try.

2) Buy a decent little portable ac and throw in there during the summer months. I know they suck, but I already have my minisplit doing its thing in there, all the portable ac would be doing is assisting the cooling by a few degrees. If adding a portable can get me around 78 degrees while dehumidifier is running I'd be perfectly happy with that.

Anyone that can throw their ideas out here or advice, would be greatly appreciated!
 
Nizza

Nizza

Well-Known Member
Try setting the mini splits to the dry mode and maybe put the dehumidifier on a little bit of a higher setting so it doesn’t kick on as often

the dry mode will not cool as quickly because it uses a lower fan speed to dehumidify faster, and hopefully this will make the dehumidifier not run and add any more heat
I would test it out and see how it works
 
psychadelibud

psychadelibud

Well-Known Member
Nizza said:
Try setting the mini splits to the dry mode and maybe put the dehumidifier on a little bit of a higher setting so it doesn’t kick on as often

the dry mode will not cool as quickly because it uses a lower fan speed to dehumidify faster, and hopefully this will make the dehumidifier not run and add any more heat
I would test it out and see how it works
Click to expand...
I'll give it a shot... thanks for the advice.
 
psychadelibud

psychadelibud

Well-Known Member
Nizza said:
Also maybe investing in some leds for the summer could be an option
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I have considered this, and may go with that next year... But need to sort out what I have for now... My crop is looking way too good right now go switch things up and I can't afford the lights at the moment.

Even CMH's would be more manageable...
 
Nizza

Nizza

Well-Known Member
psychadelibud said:
I have considered this, and may go with that next year... But need to sort out what I have for now... My crop is looking way too good right now go switch things up and I can't afford the lights at the moment.

Even CMH's would be more manageable...
Click to expand...
How old is the dehumidifier and minisplit? Maybe with a cleaning they will be able to keep up . If the coils aren’t clean they won’t work as efficient

glad to help man!
 
psychadelibud

psychadelibud

Well-Known Member
Nizza said:
How old is the dehumidifier and minisplit? Maybe with a cleaning they will be able to keep up . If the coils aren’t clean they won’t work as efficient

glad to help man!
Click to expand...
I just cleaned the coils out a couple of days ago. Its only 2 and a half years old. The dehumidifier is 3 years old and still works like a charm. I try to keep everything up to maintenance the best I can. Do you think adding like a 8,000 btu portable would help? I know they use a shit ton of electric, but I think they are making them much more energy efficient nowadays.
 
Nizza

Nizza

Well-Known Member
If you bought a portable do you think if you fix the problem you can use it somewhere else? Dual port portables are the way to go because you can vent the compressor and condensor coil heat faster.

with LEDS, 85 degrees is perfect, so that's a thought as well, it will make your ac not run as often and give you a better yield per watt (with a learning curve)
The HIDS are great though for adding heat when you need it in the winter. I would get the portable if you need to but ideally get some LEDS to swap out in the summer

is this a sealed room with co2? I am wondering how you ventilate it too, but I might be opening a big can of worms here. Plants look happy man!
Perhaps getting air cooled hoods and putting them in a sealed loop vented outside will be a great fix for the summer

Is the real problem the Humidity? I didn't see what humidity you're working with but I understand you're worried about the Dehu running more often later into flower and causing more heat issues
 
friedguy

friedguy

Well-Known Member
Can you water cool it?

I water cooled my dehumidifier by blowing the output through a computer radiator (actually 2, stacked) to pick up the heat, then a small water pump pumps the water (and heat) outside the grow room, then it goes through another radiator (actually 2, stacked) with a fan blowing cooler air through it (to remove the heat), repeat.

I don't notice any additional heat in my grow area due to the dehumidifier any more.

Previous to this, it would SIGNIFICANTLY raise my grow temps whenever it was on.
 
Renfro

Renfro

Well-Known Member
friedguy said:
Can you water cool it?

I water cooled my dehumidifier by blowing the output through a computer radiator (actually 2, stacked) to pick up the heat, then a small water pump pumps the water (and heat) outside the grow room, then it goes through another radiator (actually 2, stacked) with a fan blowing cooler air through it (to remove the heat), repeat.

I don't notice any additional heat in my grow area due to the dehumidifier any more.

Previous to this, it would SIGNIFICANTLY raise my grow temps whenever it was on.
Click to expand...
TBH this is the only real "work around" that I would consider. If done well it could remove the heat with less cost than running a portable AC unit. Simply locating the condenser coil in a container that has a float valve connected to cold tap water through a solenoid valve that opens when the dehumidifier would run it's fan. Then run a drain line from just below the water level so and use a valve to restrict flow to the floor drain. So when the dehumidifier kicks on the solenoid valve opens and cold water maintains the level say 1 inch above the drain line with the condenser coil submerged. Warmer water rises and slowly drains to waste and cold water comes in to replace it. The drain line restriction setting would be used to limit the water flow to just enough to maintain cool enough temperatures in the container.
 
Keesje

Keesje

Well-Known Member
psychadelibud said:
So lately I have had the dehumidifier set around 60 so that it does not kick on as often. But once I get to mid-end of flower, I'll need to bring that humidity on down to around 45%.
Click to expand...
It is not an answer to your question.
But I do have a question myself: why do you want your humidity to be 45% when it is 78 degrees in your room?
And did you think about getting your temperature around 83? Then the higher humidity would also be ok.
 
N

newbplantgrower420

Well-Known Member
now that u guys mention it. When I keep my temps at norm temps (~80F with co2) after w4ish my leaves start to taco up. ive had multiple strains do that to me. they grow perfectly fine so i never bothered changing the temps during the ripening stage.

they pray to the light like w1-3 or 4ish. then the leaves start to taco up as they ripen.

i think ill try lowering the temps during the ripening next run. Will 5 degrees will be enough? ive always ran the room pretty hot just to get good use of the co2.
 
Keesje

Keesje

Well-Known Member
Renfro said:
It is IMO desirable to have cooler temperatures and lower RH% during ripening.
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I you have good experiences with it, do it.
But there is IMO no scientific reason to do it.
I also think it will slow down processes in the plant.

And with a temperature of 78 and a humidity of 45, you have a VPD of over 1.5/1.6
Which is quite high. Too high according to most charts.
It also depends on your leaf temperature of course.
 
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