Fan speed question

Hi

I have a small tent that is 25 cubic feet (20 x 36 x 62 inches).

I have a 4 inch fan with 189 cfm

I have a 4 inch 45s profilter (18 inch tall filter 150 max cfm at .1 second contact time).

I figure the filter probably takes 15 to 20% of the fan speed through resistance.

I have a veriac controller.

Currently I am using it at about 30 volts (1/4 speed) to keep the light at 75% power and the temp at a max of 76.

Is there an ideal speed to run at or just what it takes to control the temp and smell?

At the current speed it should work pretty damned good. If I put it on full it sounds like an airplane in my wall (I have it on my furnace intake to get the heat out) Damned closet grow.

Let me know what you think. Thanls

I have a 27x27x62" tent and had to MacGyver a cooling solution, which may help you, dunno. For your tent maybe you would need two, one might work.

https://imgur.com/a/ZdNPv
Basically I took a 12v temp control switch ($5) wired it to an old 120mm CPU fan (mine had a small potentiometer on it, but that was a fluke, no idea where to buy one now, but doesn't matter really, just an added bit of fan control) lets say $10,
I took a $1 10" plastic pot, built the fan into the bottom, cut a hole in the bottom obviously. The whole thing drops right into the 8" port on the tents top and the temp sensor hangs inside the tent. My 8" duct goes right outside similar to your setup. Quiet by any standard I would think. The relay clicks audibly , the fan kicks on, hums for a bit, temps go down, clicks off. Every time sucking heat and odour out. Its almost like the tent is alive and breathing. lol

I built this as a temp solution until I could buy a proper temperature controlled variable exhaust fan, but its working fine so just saved myself a few hundred bucks I think. It doesn't run at all if the lights are off, and wouldn't even if it was powered on, as the temps wouldn't be high enough to trigger the switch, but I am thinking of rebuilding it with an override switch and powering it separately just in case I need to run the exhaust fan during dark period.

What ever you gota do to maintain environment.

I wish i would have known how much of a difference environment makes when i was first starting out

lights and nutes are last
imo environment first

then lights and you can grow with chicken shit if you wanted to lol (jk )but nutes should be the last thing you care much about

^disagree, first on the checklist is temp control , so that puts lights and cooling first as a matter of priority, as the light is the thing creating the heat. If thats not working nothing else will.

environment: the surroundings or conditions in which a person, animal, or plant lives or operates

Everything including the medium, nutes , light , water etc etc is "the environment", you cannot really say lights first or last or whatever, its all part of the environment, just saying. But I get what he was driving at.

Ha ha spliting hairs with definitions

Your lights are apart of the environment especially if they require active cooling.

but i would figure a smart guy would know that and would include it in the enviroment that the plant works in lol


Just saying some things are more important at first then others but yes if you need to air cool your hood that goes into the environment section in my book.


Let me rephrase for those smarter then me
Do what ever you have to do to get these things in check

These are the order of importance imo

Temps
Humidty
Air exchange to include any additional air cooling if needed.

Then lights and nutrients .

If your lights require air cooling then duh you still need to get your temps and airflow first checked off the list no matter what light you use

Im still just a noob after 15 years

If I crank the light i find it problematic to get the heat below 80 without having the 747 airplane noise in my closet. But I will screw around with an idea i have and i might be able to deaden that noise and crank it A project for the weekend. In veg they like the current conditions.
Humdity too. It is a PITA here in the winter but i have a dish with water evaporating in the tent which gets me close to 50% and that is better than the basement tent that rarely goes past 38 in the winter.