Cheap & Easy Inline fan - under $30

reverof

Active Member
Alright... So I needed more airflow into my flower room, I do hav ea small 4" inline fan hooked up to one of my lights and pulls a good amount of air out, but my intake to the room was horrible, especially when I zipped closed my door... so I decided to look aorund for some air flow and had come up with some ideas... the one I finalized on was a 7" Honeywell fan, an 8"x24" metal duct. I took the metal duct which almost fit purfect in the outflow rim of the fan, used a single screw to make a perm attachment, screwing through the rim of the fan into the metal duct, then I took black duct tape and ran around the rim of the fan and worked my way onto the duct. This basically created a single unit of a fan with a 2 foot tube extension, which I cut a whole in an out of the way area of my room and slid the duct in leaving the fan outside the room. i dont know exact cfm of this fan, but my 80cfm 4" inline from home depot isnt enough to keep up, the airflow is pushing my panda film door open out like a bubble... looking at others and comparing then I would say this is probably a 800cfm fan.

Honewell 7" fan $16.00 at walmart
8"x24" metal duct $5.96 @ Home Depot
Large roll of Black Duct Tape $7.96
single metal self taping scew $0.08

Here is exact pictures of the items I used, I will post a picture of the final product once I can get one.

duct_tape.jpghoneywell-fan.jpgView attachment 1749379

DSCN1233.jpgDSCN1232.jpg
 

reverof

Active Member
I plan on making one more of these for taking out heat form the room. The second one will be mounted on the ceiling (as heat rises) and cut a whole in the wall to the attic just big enough for the 8" duct to fit in, obviously tape around the duct & hole to seal it off form outside elements coming in. I will have about $55 total invested as I wont need to purchase another roll of duct tape, for 2 fans, an incoming fan and an exhaust fan. Works absolutely perfect and for about 1/3 the price of a single decent inline duct fan.

The fans do have a single screw mount option on the base, so is very easy to mount... put a screw where you want it, leave about 1/8th inch from the wall, slip into hole on base and slide to lock in place.
 

reverof

Active Member
Oh yeah, just a side noted, with my 4" 80cfm fan pulling air out and having to keep my panada film door unzipped halfway to relieve pressure on the door, within 10 minutes of adding this diy inline fan, temps dropped about 8 degrees F
 

Hoenhiem

Active Member
interesting, i often wondered if i could make my own air extractor. in theory it should work. i wound up buying one anyway. but thats pretty good. not sure if the cfm's would be that high though, think of it your 4" inline im gonna guess booster fan moves 80 cfm. so this fan should be on par with a 8" booster fan and that would give you a general idea. my 6" inline fan only moves about 460 cfm. but if it works it works +rep for the ingenuity
 

reverof

Active Member
interesting, i often wondered if i could make my own air extractor. in theory it should work. i wound up buying one anyway. but thats pretty good. not sure if the cfm's would be that high though, think of it your 4" inline im gonna guess booster fan moves 80 cfm. so this fan should be on par with a 8" booster fan and that would give you a general idea. my 6" inline fan only moves about 460 cfm. but if it works it works +rep for the ingenuity
As far as the CFM... I did some research and similar sie fans with 3 speeds state to push anywhere from 740-1180CFM depending on fan and speed
 

reverof

Active Member
Just a little update to my veg room. Obviosly I installed the above diy fan above for incoming air into the grow room (6x8x8). Even on the 2nd speed on the 3 speed fan I was having so much air blowing into the room, the 4" inline booster fan 80cfm was not enough to keep up obviously, I then for a temp exhaust ported my 4" inline booster into my attic, leaving a 4.25" who in my wall feeding into the open room.... I actually have more air flowing out of the 4.25" hole than the 80cfm inline booster feeding the attic. The boosters job is really pulling heat from one of my vented hoods, but also plays as an entire room exhaust. I looke din the garage and found a 90 degree 4" flange to place on it, so no light will enter the room when the veg room lights are off. With both the inline booster and the hole for exhaust, it is still not enough to keep my panda film door from bulging out due to massive amount of air flowing into the room. it has relieved some pressure but still bulging when zipped up.

I have come to the conclusion that this cheap $30 inline fan for intake is without a doubt a very very viable option and without a doubt will keep temps cooler, humidity at an acceptable or better condition and adds massively to air flow within the room.
 

reverof

Active Member
Honestly, not loud at all, my fans inside the room are louder than this one sitting outside the room.

its GREAT!
 

reverof

Active Member
After posting my answer above I took a double take on the fan, this morning when lights came on I went in and turned off all fans (except the diy inline) and off the AC, the fan is VERY quiet, almost silent and I have it on the 2nd setting at the present time.
 

reverof

Active Member
LOL.. yeah I have one of those, and hate to burst your bubble, it doesnt blow even remotely close to what that 7" fan will blow even on the lowest speed. As a test I to ok the 8" booster and added it as an exhaust to my room, along with the 4" booster thats already there, and it still cant keep up with the incoming air. So your thoughts that the 8" booster is 10x the 7" fan is downright wrong, was downright wrong before you finished posting, as the numbers of CFM from the 7" are in the area of 800-1100 cfm.
 

rzza

Well-Known Member
nono i said that the 8" booster is the same thing you ghetto built and my 240 cfm inline will blow a hundred times harder. Thats what i said and im right, sorry i bursted your bubble but ya dont gotta make shit up. Admit you had a silly idea and /thread.
 

rzza

Well-Known Member
see that, ya got people followin your lead... NO MORE GHETTO INSTRUCTIONAL THREADS!!!!!!!!!!!!
 

WillyBagseed

Active Member
nono i said that the 8" booster is the same thing you ghetto built and my 240 cfm inline will blow a hundred times harder. Thats what i said and im right, sorry i bursted your bubble but ya dont gotta make shit up. Admit you had a silly idea and /thread.
No, you are not right. I have not ducted mine like this but I do have 4 of these exact fans in my cloner and veg area. They put out a lot more than a 240cfm "booster".
Store bought "Booster" fans are the ghetto version of inline fans anyway.

Why don't you invest in a real inline fan....or is it ok by you to go ghetto as long as it is store bought. Proper DIY almost always matches and sometimes even outperforms store bought crap.

**Update : Hooked 1 of my ghetto fans up like OP and compared it to one of my 8" 500cfm inline ghetto "booster" fans. Does as well and maybe a little better.
I'll take the DIY at a cheaper price over a ghetto er..... "booster" fan anyday.

** Looks like you can slip a 10" duct piece over the ass end of it (slipped it on to see did not perma mount, a little tight, may need to split it or go 1 size larger. ) so you could put a shortie 10" on it and keep the fan on the outside for exhaust, less electrical devices for heat in grow area.

:peace:
 
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