Active Carbon Filter question

[kips0n]

Hi icm!

Im thinking about ventilation for my box 250W HPS 60x60x160h.
I spent all my money and need to build low cost odor filter. soo i want to buy 120/140 pcfan its important to be quiet and active carbon + pcv pipe

but it one problem how long must have pipe with carbon to take out all odor

1x intake pcfan at the bottom box
?x outtake pcfan at top box with carbon filter


maybe you have better idea to make low cost ventilation in my box.
i want to spend max 30-40$

 

[gdbud]

I have found that there is no low cost odor filter that you can build yourself.
I tried to build my own filter and after a few different failed attempts then looking at the costs that I had accrued at trying to save myself a few bucks. Only to find that I had spent more money trying to build it myself that I would have spent on a munfactured filter and I still had a odor problem.

 

[kips0n]

I have found that there is no low cost odor filter that you can build yourself.
I tried to build my own filter and after a few different failed attempts then looking at the costs that I had accrued at trying to save myself a few bucks. Only to find that I had spent more money trying to build it myself that I would have spent on a munfactured filter and I still had a odor problem.

Thanks for your replay gdbud!
ok soo how much money i have to spend to buy good antiodor system

 

[Mikell]

There are some decent DIY filter designs on this site if you look around, but you'll never get airflow to cool the box with computer fans. Some bathroom fans are prime.

Purchased filters are just more reliable, as DIY depends on your skill level/anal tendencies.

 

[stihgnobevoli]

i built my own filters. they work just fine. you just have to understand how the carbon filtration works i guess.

anyway the basic principle is you have stinky air/water being pushed through the carbon. the slower it passes through the carbon the more it's absorbed, the size of the carbon matters too. there's a surface area calculation somewhere. basically the more surface there is for the air to pass over the carbon the more it can absorb. if you use larger chunks of carbon you're going to need more. for finer carbon you need less.

when the air is passing through the carbon filter you basically weight the cooling vs the smell. if you are turning the fans higher to keep the box cooler but you notice more smell then you need more carbon or another way to keep the box cooler. more intake maybe?

basically there's a point where there's too much air passing over the amount of carbon you have and the smell isn't being contained.

my designs are adapted on the fly based on the need, but it's basically i think Sugarbear who did it first? basically his design modified.
i mostly use 80mm/~4inch pc fans. i recently got a larger fan it's like 5 inches. but the blade part was 4 inches so it worked out cool.

i went to casa de pot and found some of these tapered duct reducers. i think the official name is pvc reducer? i don't really look at what it's called i just look and see if it's something i can use.
this is going to be the filter body. i just need glue, tape, carbon, and this little trick i learned from another guy whose name i forget. i use air vent filters for the filter material. you can just cut it with some heavy duty scissors like you kill a chicken with. nothing fancy.

step two: you cut and glue a piece of the air filter in the bottom of the pvc unit you choose to use. i use 3"-4" reducers. once that's nice and dry, check to make sure you sealed it well. shouldn't be too hard since this filter material will soak up the glue. i used gorilla glue...the #1 they sell at the store. not the #4. shit's too sticky.

step 2er: fill with carbon and test. ok my test was really about airflow. i need my box to not be an easy bake. so i fit the filter in place. my box has 3 inch holes cutout for the fans. i just put fan over box, trace hole in center of where fan blades are doing their work. cut a hole in cab and screw in fan. done'ski. anyway since theres holes in my cab that's why i went with this design. i just shove it in the hole and tape around to cover any gaps. its not permanent so no glue is involved except the bottom of the filter.

...ok so to test i shove the half done filter on (my vents are at the top of my cab btw, heat rises.) the hole and turn the fan on full speed. then i start adding carbon. depending on your fan speed through the empty filter adjust how much you add initially or else you're gonna have a huge mess on your hands. i can't stress that enough if you do everything exactly step by step how i did it. so anyway you adjust the amount of carbon in the filter with the fan on till the point where theres enough restriction to keep the carbon from blowing away while it's open. this should be enough to keep you from putting strain on your fan and mostly just blowing hot air backwards over the fan blades. i dunno what this is called off the top of my head. but there's a word for it i'm certain. imagine a fan sitting against a wall turned on full blast. you might wanna use just a little bit less carbon than that actually. just a touch.

step: lastly. ... shit i forgot to tell you about the test...

...ok now lastly for real. you just cut another piece of filter and glue it over the other end. you don't have to worry about packing it if you tested it the way i did it. the fact that it didn't blow away lets you know you have enough to do the job. so it doesn't really need to be filled to the top. but in the interest of keeping dust down you might wanna pack in a little like polyestereneyolenine? whatever the fuck its called. the shit in pillows. put a very loose layer between the carbon and the top filter cover to catch any loose carbon dust that may work it's way up over time.

but anyway that's what I did to make my filter and it DOES work just fine. if i notice i can smell anything i just replace the carbon. i didn't glue it all together so it's a matter of taking off some tape and then taping it back up after i'm done. if i'm careful i can even reuse the tape.

hope this helps.

also i and most people use passive intake. just let the suction from the exhaust pull in air. you can cover your intake holes with the filter material to keep out dust and bugs. just a little protip. if you for example use 2x 80mm fans on top you want 2x the intake. so at the bottom you need 4 (FOUR) x 80mm holes. but if you do the fans for the intake you can prolly get away with 2x80mm exhaust and 1x80mm intake.

this is just what I do. it's up to you to copy and modify it or not.

lol i just noticed i said basically like 8 million times. can you tell i'm high?

 

[stihgnobevoli]

oh yeah one more thing. i found through my experimentation if you have weak PC fans like i use, you will want a gap between the carbon and the fan so it can build up pressure i guess? or equalize pressure maybe is more accurate. but with a strong fan it can blow through the carbon easier than a weak fan. so for the weak fan to compensate you have to give it room to build up speed i guess is the best way i can put it.

like ferrari doing 0-60 in 3 seconds vs a toyota camry doing 0-60 in 15 seconds. camry gonna need more room to build up speed.

 

[kips0n]

stihgnobevoli thanks for your replay!
its very helpful for me, i think i test your way but i dont use a pcfan i will buy bathroom fan 125mm fi or 100mm
but you know i can spend more money for good fan when i build filter. Active carbon is cheap, pcv too so i can spend more money for good fan.

maybe you know guys good and checked fans? i see nice and silence but it cost around 100$ now its too much for me.

 

[kips0n]

ok how much CFM must have my fan if i have 0.648m3 ?

 

[stihgnobevoli]

the more airflow the better. if noise is no concern get the fastest most reliable one you can afford. if you have a hot box. your 250 is gonna be significantly hotter than my 100w. even when i use my 70w too for 170w total i can still cool my setup. with 2 strong pc fans. these one move like...i don't have one near me but 35+cfm. i dunno what that is in metric. divide by 3 i think. 10cfm. but for you i would get a faster fan. if your box can justify it just get one of those inline centrifuge fans. i saw one at case de pot for like $60 bucks and it fits 4inch ducting. perfect for my needs. you could use that, and get a longer pvc tube or just connect 2 reducers with a collar. .6m cubed? is that like 1.5 feet? if it's only 2footx2ft or so you can get away with a fan that moves like (the rules is something like 1-3 atmosphere changes a minute. 4cubic feet x3 = 20cfm at least. i suck at math also you may wanna run your own numbers. also have a look at this thread.

https://www.icmag.com/ic/showthread.php?t=112862

Red lays it all out. so many legends come and gone.

 

[kips0n]

the more airflow the better. if noise is no concern get the fastest most reliable one you can afford. if you have a hot box. your 250 is gonna be significantly hotter than my 100w. even when i use my 70w too for 170w total i can still cool my setup. with 2 strong pc fans. these one move like...i don't have one near me but 35+cfm. i dunno what that is in metric. divide by 3 i think. 10cfm. but for you i would get a faster fan. if your box can justify it just get one of those inline centrifuge fans. i saw one at case de pot for like $60 bucks and it fits 4inch ducting. perfect for my needs. you could use that, and get a longer pvc tube or just connect 2 reducers with a collar. .6m cubed? is that like 1.5 feet? if it's only 2footx2ft or so you can get away with a fan that moves like (the rules is something like 1-3 atmosphere changes a minute. 4cubic feet x3 = 20cfm at least. i suck at math also you may wanna run your own numbers. also have a look at this thread.

https://www.icmag.com/ic/showthread.php?t=112862

Red lays it all out. so many legends come and gone.

thanks ive readed this topic but now i have other problem i want to buy Duct fan 2-speed 145-187m3 / h, fi 100mm can i plug carbon filter
Prima Klima Eco-Line fi100mm, 160-240m3 /h
and smell will be totally reduced?