Oscillating fan causing high humidity during flower!

[hazeluv69]

As the title says, my oscillating fan is causing my humidity to rise too high in my grow tent and I’m like a month into flower so I tend to leave my extraction on 24/7 but no blowing air on the leaves as it’s raising humidity as I don’t want no Mold or rot. Is this okay that I’ve got my extraction running and no oscillating fan? I only have oscillating fans and the one extraction, nothing else. Help appreciated

 

[Stormblessed]

I’m not positive but I feel like if the humidity is rising due to it being removed from the leaves, it might b beneficial to have the oscillating fan on, better the humidity not b on the leaves, that’s there mold and rot comes from

 

[hazeluv69]

I’m not positive but I feel like if the humidity is rising due to it being removed from the leaves, it might b beneficial to have the oscillating fan on, better the humidity not b on the leaves, that’s there mold and rot comes from

Yeah I understand that, I’ve even hung my tower fan from the top of the tent ffs because I figured the fan being on the floor was pushing humidity up from the bottom but it’s also occurring when it’s hanging in the air, shall I just stick the fan on the ground?

 

[NuttyProfessor]

have you a fresh air intake you need to change the air a lot in flower

 

[hazeluv69]

have you a fresh air intake you need to change the air a lot in flower

Second grow, no excuse but I only have an outtake exhaust pulling air out the tent and I open the tent a few times a day and oscillating fan, all holes closed as I do not want any bugs etc entering my tent

 

[Emilya Green]

I have never seen an oscillating fan cause an increase in RH unless you have a lot of water sitting around in the tent, such as in the drip trays. By not having strong fan action in your tent, you ARE inviting mold and mildew to grow in there, because the leaves throw off moisture... that is what they do. The moving air is the only way to get rid of that moisture on the leaves, and your extraction fan is the best way to send that air away, by totally exchanging all the air in your tent several times an hour.

 

[hazeluv69]

I have never seen an oscillating fan cause an increase in RH unless you have a lot of water sitting around in the tent, such as in the drip trays. By not having strong fan action in your tent, you ARE inviting mold and mildew to grow in there, because the leaves throw off moisture... that is what they do. The moving air is the only way to get rid of that moisture on the leaves, and your extraction fan is the best way to send that air away, by totally exchanging all the air in your tent several times an hour.

When my oscillating fan is on, my humidity will go from 49/50 all the way up to maybe 75? But if that’s ok as it’s the moisture throwing off the leaves then I’m ok with the fan on?

 

[hazeluv69]

Up to 80 RH now with the oscillating fan on high speed!

 

[Emilya Green]

When my oscillating fan is on, my humidity will go from 49/50 all the way up to maybe 75? But if that’s ok as it’s the moisture throwing off the leaves then I’m ok with the fan on?

I suspect that after it has been on for a while and the air exchange has had its chance to do its thing, the RH will drop dramatically. That must be quite the sensitive instrument you have there!

 

[hazeluv69]

I suspect that after it has been on for a while and the air exchange has had its chance to do its thing, the RH will drop dramatically. That must be quite the sensitive instrument you have there!

Yes I turned it off will put it back on now and check in an hour

 

[hazeluv69]

RH did not gradually drop but reached around 82, so I just switched the fan off as it had been on for a while

 

[HutchBenedict]

Can you tel if your extraction fan is actually extracting? Also, open one of the vents at least so it can suck air in. Intake fan would help but at least open a vent.

 

[hazeluv69]

Can you tel if your extraction fan is actually extracting? Also, open one of the vents at least so it can suck air in. Intake fan would help but at least open a vent.

Yes I can tell lol as the other end of the extraction the air is humid, etc & if I open the vents I don’t want any pests?

 

[Herby Paisley]

Hi Hazeluv69... Just curious is your oscillating fan motor producing heat? Being in a closed off tent that could raise the humidity over time, always vent in new cool air and vent out old air no matter what ,you need negative pressure in tent to push old air out.

 

[Calvados]

Second grow, no excuse but I only have an outtake exhaust pulling air out the tent and I open the tent a few times a day and oscillating fan, all holes closed as I do not want any bugs etc entering my tent

This sounds like the problem. How does air get into your tent when it is closed? What size/type tent is this? Pic would help.

 

[hazeluv69]

This sounds like the problem. How does air get into your tent when it is closed? What size/type tent is this? Pic would help.

1.2x1.2m I don’t have any intake atm!

Hi Hazeluv69... Just curious is your oscillating fan motor producing heat? Being in a closed off tent that could raise the humidity over time.

The fan doesn’t seem to produce heat , the humidity rises within a few minutes of it being on

 

[Herby Paisley]

1.2x1.2m I don’t have any intake atm!


The fan doesn’t seem to produce heat , the humidity rises within a few minutes of it being on

Calvados Is right I believe your humidity problems are being caused by no fresh air intake wish I had seen that post earlier about no air intake. You need it cool and breezy in there, don't worry about the bugs there are ways to prevent and battle them if an issue arises.

 

[Fuzzy Duck]

Some thing wrong with the set up of the grow area !

If you can post pic's of your grow tent & what ya growing in will help to find a solution as some of us do have an insight into problems & yes it is a guessing game some days depending on information we have to work with


Fuzzy Wuzzy madness...

I think it is extraction & to that point as in the same room to which you are just recycling the same air via passive intakes on your tent ?

Either that ya growing in a garage or shed with ambient RH of air being high... Perhaps it could timing of lights on or off in the natural day cycle when in real life RH go's up in real life night time ?... you can check this out on any decent online weather forecast.

This may lead me to think about type of light source you are using, any one using Hps or Mh the Rh will lower due to heat created from bulbs but you will get less heat from cfl T5/8 tubes and even led.


If any of that rings true we just need details to help... fans don't increase RH.

 

[hazeluv69]

Calvados Is right I believe your humidity problems are being caused by no fresh air intake wish I had seen that post earlier about no air intake. You need it cool and breezy in there, don't worry about the bugs there are ways to prevent and battle them if an issue arises.

So I’ll open a vent of the vents? Top or bottom of the tent?

 

[Fuzzy Duck]

Calvados Is right I believe your humidity problems are being caused by no fresh air intake wish I had seen that post earlier about no air intake. You need it cool and breezy in there, don't worry about the bugs there are ways to prevent and battle them if an issue arises.

Does your tent have passive intake vents which can be opened up.