Efficiency please!

[Night713]

I used to run an air cooled hps and I’ve recently switched to led so I’m learning a bit. I currently am having trouble getting my humidity down. At night it can be upper 70s% rh . Hovering around 60-63 during day. There are no ducting ports on the bottom so I realize intake placement isn’t ideal.

1.I live in a humid climate.

2.I have a wall ac that I can duct into my tent(first pic and yellow circle in third pic)

3.I have a 6inch exhaust fan in my attic with a speed controller (second pic blue circle third pic )

4.The tent does not have intake options on the bottom just a flap I can open but not duct into really, only on the top of the tent

5 the room the tent is in is a laundry room with no central ac just the window unit as mentioned

I feel like I’m doing a dance between pulling cool air in but also getting rid of it but not the humidity. If anyone has any input on how I can keep my humidity down and not keep my ac running constantly that would be great. I’m not getting my overnight dry backs and I believe it’s partially due to my high humidity.


View attachment IMG_2297.jpeg View attachment IMG_2298.jpeg

 

[Rocket Soul]

Warming the space you are drawing air from will decrease RH.
If youre looking for a "energy free" way to decrease humidity which doesnt involve venting in drier air I don't know about one.

If you want to extract less heat and humidity from your tent extract from the bottom.

 

[troutman]

I vent out at the top on one side and vent in from the bottom on the other end.
Heat rises and this creates a more natural air flow. At the end of day, I also open
the tent door just minutes before lights out and don't enter the room until the
lights goes on the next day.

 

[Rocket Soul]

Looking at your numbers again, to me they seem ok yet a bit high for your dark cycle. Whats your temps like? If you grow with high RH its usually fine as long as you dont go down to much in temps and if you have sufficient air movement, especially when rh is high at night.
Terps dont like the higher rh though, maybe a little bit of heat during the main part of flower and then ACed cool and dry air during the last 2-3 weeks.

 

[Onboard]

Switch the AC back on, until you figure something out?

Does that sort out your temp/humidity issues? In that case, it may be worth it, even if it costs a lot in electricity.

EDIT: Looking at it again I think I would suggest you go warmer, not drier. If your temperatures have dropped, the plants may be unable to convert all that strong LED light, and that may be the explanation for them not drying back as they used to. In that case, you could dim down the light a bit until they start drinking, and you get you temps back up.
If this is indeed the case, a radiator inside or outside the tent may do the whole trick for you - getting the temps up and RH down at the same time.

The AC, as well as the attic duct fan will, most likely, just make things worse (by removing even more heat from the room).

At least my plants like it much better at 80-85F / 26-29C than at 75F/24C. Yes 63% RH is a bit high in flower, but mostly for the risk of bud rot at the end. Most plants won't mind 63% RH at all, IME.

 

[Rocket Soul]

Switch the AC back on, until you figure something out?

Does that sort out your temp/humidity issues? In that case, it may be worth it, even if it costs a lot in electricity.

EDIT: Looking at it again I think I would suggest you go warmer, not drier. If your temperatures have dropped, the plants may be unable to convert all that strong LED light, and that may be the explanation for them not drying back as they used to. In that case, you could dim down the light a bit until they start drinking, and you get you temps back up.
If this is indeed the case, a radiator inside or outside the tent may do the whole trick for you - getting the temps up and RH down at the same time.

The AC, as well as the attic duct fan will, most likely, just make things worse (by removing even more heat from the room).

At least my plants like it much better at 80-85F / 26-29C than at 75F/24C. Yes 63% RH is a bit high in flower, but mostly for the risk of bud rot at the end. Most plants won't mind 63% RH at all, IME.

63 seems ok to me as long as you maintain temps and have a lot of air movement even though ideally a bit lower at the end. But basicly agree, no need to worry too much

 

[Stone]

I would thoroughly research PPFD for light decisions, and VPD (more important for your question).
Then design your optimal plan.
VPD is far more telling for what a plant experiences than temp or humidity alone.
Not that those factors alone don’t have significance. But that’s mostly when they are way out of bounds enough to cause problem alone.
All the suggestions to raise heat are essentially telling you to alter your vpd that way.
And generally that’s a good suggestion, especially for LED.

 

[Stone]

Ok I reread, and the super obvious simple solution my have passed is all.
Dehumidifier

Specifically a small in tent unit.
This will both drop humidity and raise temp.
Although with it it might be one or the other needed.
Still advise going with higher temps and co2 especially.

 

[CaffeineAI]

Ok I reread, and the super obvious simple solution my have passed is all.
Dehumidifier

living in a high humidity area, they'll need to invest in a good dehumidifier.. most of the budget consumer models will fall apart with chronic usage (frankly, even just casual usage in humid area) and produce minimal results.

In any case, they should supplement with making baking soda & charcoal filters... you can 'box' in a thin frame wrap with a breathable fabric and pour in, create several of these filters and place around in varied spots or box it in. It'll help reduce some as well. Needs to be changed out regularly, maybe once or twice a month. Additionally, separate to the grow area - if one is allowed to renovate.. this is where it's nice to modify your walls facing outwards on the regular. . so, able to open and change out insulation as needed. Ah, yeah, additional additives are varied types of salt (rock, silca, calcium chloride, etc) - obviously, you don't want to effect your grow space, but lining the interior of the exterior walls (ceilings too, if it's accessible) with the salts will help reduce humidity (they may need to be replaced every few months) while placing a vapor barrier over it (seal/foam around the edges if paranoid) should reduce salt risk to the grow space while also lowering humidity to a degree..

 

[Grapefruitroop]

I’ve recently switched to led so I’m learning a bit

Hi there! Those numbers are totally fine with LED lights....
You want slightly higher temps and rh compared to HPS....