exhaust 24/7?

DIRTHAWKER

Well-Known Member
I have an 8x8x8 sealed room, with two passive lightproof intake vents. I just hooked up a 435cfm exhaust fan sucking air and pushing it into the attic.
the negative pressure is awesome (its hard to pry the door open beacuse of the pressure).

Soon i will have 4 600 watt lights and 30-40 small plants inside.

my question is; beacuse airflow is a good thing, shouldnt i leave the fan on 24/7? It seems like bringing in constant fresh air would be great.

I also have a wall mounted oscilating fan running and will probably add one more.
 

offgridgrower

Well-Known Member
dirt I have the same size room for veg, and i have my exhaust set up the same way, i turn my exhaust off 30 after the light goes off and on 30 after it comes on, i do an 18/6 but have the fan come back on for hour in the middle of the off period, to help lower the humidity, i am using panda roll, I think your setup is drywall painted flat white, so your hum may stay a lil lower than mine do to the drywall adsorbing more the moisture than my plastic room. I need a small osccilating fan, went to look for one the other day, and since its fall, no stores have small desk fans right now!!!
 

Boneman

Well-Known Member
Depends on a few things. Is your exhaust used in conjunction with cool tubes or is a filter hooked up to it?
My carbon scrubber is attached to my exhaust fan and I dont use it until flowering or when the stink starts. I have a fan located next to a screened and mostly light proof intake always blowing in fresh air.
My cab isnt sealed quite as well as yours but I dont have any light issues either. No chances for light leaks whatsoever.
 

Jtoth3ustin

Well-Known Member
i dont have no fancy exhaust setup (yet)... but for my tent i just got. im keepin it on 24/7, and its just a floor fan next to the air flap on the bottom, and another fan inside pushin the air up and out..... think bout it..... its like saying the wind wont blow at night. when usualy its the worst?????
 

DIRTHAWKER

Well-Known Member
my exhaust isnt hooked to any hoods, i was gonna aircool the hoods seperatley later when needed ( im only adding one light at a time)
ending with 4.

As far as a filter, i made a carbon filter out of an airconditioning filter and activated carbon, it will attach to the intake of my exhaust with a hose clamp. Of course i wont need to attach it for a while.

Im just thinking ahead, and hopefully within the next few days i can scrape enough money together to get the ballast and bulb so my FAST growing veg plants in my veg chamber can be put into the flower room.

I am still not clear on what the consensus is 24/7? or maybe 5 minutes every hour?
or is this one of those things that you have to kinda monitor and see first hand and then adjust accordingly?
 

offgridgrower

Well-Known Member
well i forgot to ask you, your whole area is going to be used for both veg and bloom?
cause what you need to figure out is, how long it takes for your area to heat up past the ok point, and how long it will take your fan to bring the temps back to normal, then you could setup an on/off time for you fan. but if your using it for both, then 24/7 may be your only option when it comes to smell vs heat.
 

DIRTHAWKER

Well-Known Member
No offgrid... my flower room is just a flower room.

my vegroom is seperate and already dialed in, its not sealed but has constant airflow from a fan and seems to be working great

the reason i am asking is beacuse my flower room is sealed and i think the only way to get constant fresh air is by leaving the exhaust fan on 24/7.

but thanks for answering my question..yes i guess i will need to monitor it to see. but my other qustion still remains.. isnt constant fresh air worth running the fan 24/7?
 

offgridgrower

Well-Known Member
No offgrid... my flower room is just a flower room.

my vegroom is seperate and already dialed in.

but thanks for answering my question..yes i guess i will need to monitor it to see. but my other qustion still remains.. isnt constant fresh air worth running the fan 24/7?
well since you answered that for me, y would you need to run the fan when the lights are off? if you have an oscalating fan in there when the lights are off you should be ok. are you going to run CO2 in there?
have you been to this site?
CO2 Calculator - Greentrees Hydroponics
it was very helpful
 

DIRTHAWKER

Well-Known Member
I see... so im assuming that oxygen levels will be sufficient in a sealed room during lights off inside the room without having to bring any in?

co2 will eventually be added, im babysteppin with the coin of the realm..LOL
 

offgridgrower

Well-Known Member
I see... so im assuming that oxygen levels will be sufficient in a sealed room during lights off inside the room without having to bring any in?

co2 will eventually be added, im babysteppin with the coin of the realm..LOL
your plants dont need oxygen to grow, you are removing oxygen from the room once they have used all the co2 in there, which can take up to about 3 hrs depending on the variables, but they say that you should breath the room at least every 3hrs at min.

brainfart tonite I was mounting fans in the attic to test out the tent with the cool tubes and both 1k's running to see how long they took to heat up the tent, then to see how long it took the fans to cool the lights and the room, this is with out the scrubber and it's fan hooked up. And the neg pressure from both 8in vortex fans was intense!!
then it dawned on me that instead of using 1 fan to cool each light, I should use 1 fan for both lights and run flex duc to connect the bottom of the cool tubes (have my hps vert) that way my fan for cooling the lights draws air from the attic or outside if i install a roof vent, cools the lights and goes back into the attic, that way my scrubber fan vents the co2 out and i can keep my cooling fan running the whole time the lights are on! volia flood co2 and wont be sucked out by the fans cooling the lights!! then scrubber fan can run on intervals during the entire bloom!

sorry for blowing up your thread but like i said it was a brain fart and I felt like kicking myself after doing all the attic work, and now having to go back up and do it again!!! lol
 

DIRTHAWKER

Well-Known Member
Your brainfart just made me realize a few things. THANKS.

And im glad you are blowing up my thread, this is how things get worked out.
 
Top