Madjoints91
Active Member
What do you guys use for air flow?intake fan are extractor fan, and which would you prefer to use and why
Thanks
Thanks
Intake are extractor
- Thread starter Madjoints91
- Start date
0vergrown420
Well-Known Member
Most people run negative pressure (extractor fan). When its hooked up to a carbon filter it keeps nosy neighbors from smelling you treasure lol
420burn420
Well-Known Member
depends on your temperature and what you're trying to accomplish. If your temps are above 90 degrees because of your light etc. I would do the intake /exhaust and periodically open the tent to decrease heat, humidity might drop but should be ok if it's 30% and up. In my case it's turning to fall so temps are dropping and it's good at night , plus the plant is growing so I raised the light and can get it closer to the fans to decrease the heat.
Madjoints91
Active Member
Well that's what I have set up bud, but just came across it on the web, so thought I would ask the question to as what people prefer, they would only think it's my next door neighbor anyway as he's a mega stoner lol
Madjoints91
Active Member
The led light I use only heats it up to around 28 degrees, I feel it's not enough, but the plant is growing, , so I wasn't sure which I would be better off with an intake or extractor, I dod have a heater on to heat it up but found it was getting way to hot and that was on the lowest setting, so I though about buying a smaller heater maybe.
HydroKid239
Well-Known Member
I have a cheap yield lab 4" fan for exhaust. That is changing to be my intake as I have an AC Infinity on the way with temp & humidity control.
Why? because I run temps too hot with my light. LED can run perfectly at 85-88F..above that, and you may have issues.
Madjoints91
Active Member
Yea mine definitely don't go above the 30 mark, it's obviously enough to help the plant grow but would you recommend a slightly higher temperature than that
HydroKid239
Well-Known Member
In veg use the intake to keep your humidity.. as long as the air you pull in isn’t dry. In flower with less humidity needed.. hit the exhaust to help you banish the moisture from the tent.
HydroKid239
Well-Known Member
You will most likely run it to more humidity that you can handle.. that’s when a nice dehumidifier comes in handy.
Madjoints91
Active Member
Sweet thankyou mate, il keep that in mind
Renfro
Well-Known Member
As biomass increases I go from having to run a swamp cooler to raise humidity to running a dehumidifier, especially when the lights are out and the AC isn't pulling any condensate.
So be aware that conditions change as the biomass increases. Monitor the conditions as the plants grow, especially the lights out numbers. When the lights are off we are no longer fighting heat but the humidity can spike quickly after the lights go out. The plants stomata are still open and transpiring for a good 20 - 30 minutes after lights out. Combine that with a temperature drop and the relative humidity is getting a double whammy. Just having a temperature drop can cause a significant change in RH%.
If we have air that is 80F and 50% RH and we allow that same air to cool down to 70F the RH% is now over 70%.
Being able to vent to control humidity will depend greatly on the ambient RH% and air temperature. Obviously we can't lower humidity using humid air. Something to remember, cold air is dry air. So if your intake air is 45F and 100% RH (raining lol) that air only has around 6.5 grams of water per kg of air. At 70F that equates to about 40% RH and at 80F we are down to around 30%. Therefore if I run my intake to cool my grow room during the winter and it's snowing outside, I don't have to worry about the intake air being too moist.
With ambient humidity being very high in some regions it can become pretty much mandatory to have a dehumidified and air conditioned grow. When I grew in Missouri I wouldn't even consider using intake from outside because of the humidity. In Colorado the air is so dry all the time that using cool night air to cool a room became an option.
So be aware that conditions change as the biomass increases. Monitor the conditions as the plants grow, especially the lights out numbers. When the lights are off we are no longer fighting heat but the humidity can spike quickly after the lights go out. The plants stomata are still open and transpiring for a good 20 - 30 minutes after lights out. Combine that with a temperature drop and the relative humidity is getting a double whammy. Just having a temperature drop can cause a significant change in RH%.
If we have air that is 80F and 50% RH and we allow that same air to cool down to 70F the RH% is now over 70%.
Being able to vent to control humidity will depend greatly on the ambient RH% and air temperature. Obviously we can't lower humidity using humid air. Something to remember, cold air is dry air. So if your intake air is 45F and 100% RH (raining lol) that air only has around 6.5 grams of water per kg of air. At 70F that equates to about 40% RH and at 80F we are down to around 30%. Therefore if I run my intake to cool my grow room during the winter and it's snowing outside, I don't have to worry about the intake air being too moist.
With ambient humidity being very high in some regions it can become pretty much mandatory to have a dehumidified and air conditioned grow. When I grew in Missouri I wouldn't even consider using intake from outside because of the humidity. In Colorado the air is so dry all the time that using cool night air to cool a room became an option.
