Pushing a lower CFM fan through higher rated Phresh filter

Alright I'm completly new to this and am attempting to build from sctratch my first grow cab. I live in an apartment so stealth is super mega important. I've managed to locate a inline fan that people say is dead silent even at full speed. Here is the fan: http://tinyurl.com/ogz47h4.

The fan is rated for 80 CFM, and I'm looking at a 4 by 12 inch phresh carbon filter: http://tinyurl.com/p5bdm59 ...rated at 200 CFM

So my question is if I mounted this fan at the top of my cab would there be a decrease in filtering or some other negative outcome from using this combo to pull the air out. I feel this may be overkill but I'm hoping to kill 100% of anything that would give it away as anything other then a boring old wardrobe.

Thanks

hi, I allways prefer to oversize the filter, just be prepared that the filter will reduce the cfm of your extractor fan by a bit so make sure you've oversized the fan cfm aswell, and I didn't have a good look at your fan but are you sure that's an inline one?

Well It's not inline. Its more like the ones you use in your bathroom ceiling to pull humidity out of the air. Is it not the same idea though? I'm working on an idea to put the white grate at the very top of the cab with the fan housing and carbon scrubber sitting inside of a bottomless Rubbermaid tub sat on top of the cab to hide them. Would this fan and set up work? I've picked this particular model because the reviews say it is a quality fan and runs very quietly, which is a def perk for what I'm going for.

I'm sorry if this is ignorant or confusing. I'm eager to learn, but even after reading everything I could, the hardest part seems to be taking these ten million facts and actually designing the set up with them.

Those fans dont have the power to suck air out of your cab. Buy a 440 CFM fan and a fan controller. You only need 80 cfm, so you turn the fan down. i run mine at 35 percent and its quieter then the air king circulation fan in the room.

Would I want to buy a 440 CFM fan of the same type, as they do make them, or would it be better to go with an actual inline fan suspended from the ceiling and make due with it sharing space with the lights?

If so what would be a good one to look into?

For stealth this is the best fan speed controller you can get. Absolutely silent, and won't cause the fan to humm either.

http://www.amazon.com/gp/aw/d/B006NGI8VS?pc_redir=1414049470&robot_redir=1

My grow is not stealth but that cheap speed control from the hydro shop annoyed the hell out of me, it just sounded ill. It chopped up the power, on/off/on/off how ever many 100's/1000's of times a minute to reach your desired speed. This unit reduces the power legitimately, it doesn't just turn your fan on and off super fast.

This is how I do a lot of learning....... by searching first. Google;
Pushing a lower CFM fan through higher rated Phresh filter
That was your thread title.



Click the very first link. 2nd link is now a link to this thread 1st link brings you here

http://www.phreshfilter.com/faq.aspx





Which hives you a solid answer to your question.

Joven Agricultor said:

This is how I do a lot of learning....... by searching first. Google;
Pushing a lower CFM fan through higher rated Phresh filter
That was your thread title.

View attachment 3286187

Click the very first link. 2nd link is now a link to this thread 1st link brings you here

http://www.phreshfilter.com/faq.aspx

View attachment 3286188
View attachment 3286189
View attachment 3286191
View attachment 3286192
Which hives you a solid answer to your question.

Click to expand...

if everyone did that there would be barely any questions, resulting in barely any posts, resulting in a very small community. lets encourage people to communicate with eachother! thanks for being helpful at any rate

Sorry, was definitely not trying to discourage anyone from posting at all. Just encouraging the learning process. There will always be thousands of post and questions to be answered! In fact with this post now showing up in search results, it's sure to get that question answered for others wondering the same thing

I would also say that for a stealth cab in an apartment, 440 cfm is probably way overkill, unless its on an air cooled light. If it's just for air exchange 170cfm 4" is what I'd use. I use that with that variarc for the air exchange on my veg cab 4x4x4 cube in an air conditioned room.

Also lighting. Are you going fluorescent or led, or you sticking an hid up in there?

using a size bigger phresh filter is the suggested method!

Thank you so much. I'm sorry,and honestly I'm pretty embarrassed. I'd read that FAQ page probably three times before I posted here. Just so many questions and so much ground to cover. After looking into it I've went with the 171 CFM 4 inch Hurricane inline paired with a 200 CFM phresh filter. I plan on purchasing the variarc, as well as building a sound box lined with this materialhttp://www.supersoundproofingsales.com/SSP-Foam-Mat-1_8-thick-by-48-wide-per-foot/productinfo/09-42719/ to completely kill the sound of the fan.

As for lighting I've read up on the different options and because of the inline I'm think of using this light kithttp://www.amazon.com/gp/product/B009HVVN1S/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A3VTE9RTFS7WGL from Amazon as my grow light as it's set up seems much easier and cleaner then multiple CFLs.

Once again thank you I think my brain had burned out from reading grow articles all day, and playing engineer. Its not used to all this heavy lifting.

It's all good dude! It's kind of like using a 3 ton jack to lift a 600lb. moyorcycle, it will work, really good, and the jack will probably last longer than if you were lifting the rated 3 tons with it. I too use the 200cfm on my 170 fan. I know ghe filter knocks the flow down to below 150, I'd rather be oversized.

How big (LxWxH) is your cab gonna be? I ask because you may be able to throw a 400 in there. I'm going to a 600 from a 400 for veg and using the 400 in a stealth cab for another mmj patient. That cab will be 18x36x48", desinged to hold 2 plants in 3.5gallon buckets. The 250 may be perfect for your needs. I just like the thought of growing more meds than I need incase something happens to some of the crop, if your dosage goes up, if another patient is in need, if you wanna be able to overmedicate without worrying about running out. Just some thought. At .5 gpw a 250hps will give you 125 grams per harvest. I haven't harvested as I'm flowering my first grow. I'm hoping for a minimum of .25 gpw as a complete noob, that'll be 250 grams from my 1k. I'd be so stoked to get .5 gpw. My buddy did soil as I am, he did it for 7 years before going hydro, it wasn't till his last year in soil that he hit .5 gpw. A 250 watt at .33 grams per watt is 82.5 grams, is that enough to last you between harvest? .33 gpw on a 400w bulb is 132 grams, that's a big difference. As far as electricity cost, my 400w cost me probably about $35 a month @ 18hrs a day.

Well I'll be growing in the top portion of this. The bottom has a depth or 20 7/8in and a width or a little more then 42in. The depth will be slightly smaller due to the fact that I plan on installing a light trap made of pink foam insulation like in the pic below for my passive air intake. The drawing not spot on as I dont think it will span the entire bottom back of the cab.

as for the height its at least 4 1/2 feet but I'll now for sure here later tonight as I'm actually on my way to pick it up at the wollyworld. Once its up I'll measure everything so I can actually get started on putting all the systems together. My only concern with a stronger light kit is that it will scorch my poor girls. The lights are the one part that really has me confused. Would the light I posted above be good for 3 plant scrog or LST. I wish I could get more opinions but I don't want to spam.

My plants are done strecthing, they are in 11.5" tall buckets and stand 29" tall. That leaves 19" above them in a 48" cab(my flower cab is 6'4") optimal penetration for a 400 is 6"-21". A 6" cool tube hanging 3" below the top would give you 10" between top of your canopy and bottom of the cool tube. I lst'd yhe shit out of my plants, they were 6"tall bushes when I flipped to 12/12, they stretched almost a foot. I'd run the 400 and keep a low scrog net, 6" above the buckets, or use big square pots and just lst.

There is a light penetration chart

The 250 Needs to have atleast 5 inches between the canopy and bulb, the 400 needs 6". To me there is no question, run the 400.

I've got a similar question,

I've got a 70 CFM fan currently on my box. I've just purchased a 100 CFM 4 inch booster fan. I was thinking of running a six inch diameter piece of ducting from my box fan ( about 3 feet long), then reduce it to four inches( diameter ) to accommodate my booster fan, then a four inch 90 degree piece to my four inch 200 CFM carbon filter. I know you need a existing fan in order for the booster to function properly. Any suggestions? My box is about 10 cubic feet. I'm using CFL's, heat is really not an issue, it always runs between 70/80 degrees. I'm primarily using this new system as an odor control, heat control setup.

Thanks in advance.

Sherman420

Dakigreen-san said:

Alright I'm completly new to this and am attempting to build from sctratch my first grow cab. I live in an apartment so stealth is super mega important. I've managed to locate a inline fan that people say is dead silent even at full speed. Here is the fan: http://tinyurl.com/ogz47h4.

The fan is rated for 80 CFM, and I'm looking at a 4 by 12 inch phresh carbon filter: http://tinyurl.com/p5bdm59 ...rated at 200 CFM

So my question is if I mounted this fan at the top of my cab would there be a decrease in filtering or some other negative outcome from using this combo to pull the air out. I feel this may be overkill but I'm hoping to kill 100% of anything that would give it away as anything other then a boring old wardrobe.

Thanks

Click to expand...

Im running a Panasonic FV-08VKS2 80cfm pushing through a Mountain Air 6" x 20" 265cfm (not the big air version, those have thinner carbon bed the original I have is 2" thickness). Blowing through the filter muffles the exhaust sound enough to where it is in half of a closet with sliding doors and with half of the closet open for airflow its essentially inaudible. I run a 6" ducting piece into the 6" inlet of the fan and foil taped that to seal it then run the 6" ducting to an exhaust port on a tent (or cab if your using that). I made some ghetto cardboard 6"-4" adapters for the 4" exhaust to adapt to the 6" carbon filter, just used 3 layers of cardboard taped together and cut out like donuts with 6" outer diameter and 4" inner diameter and foil taped the joints to seal. Zero smell (with the tent zipped up) and basically silent with it in the closet.

Biggest carbon filter you can afford is the way to go if you want stealth. Mountain Air is the best brand filter I ever used for complete odor control, Ive used ebay filters and DIY filters and they never worked well. Also a good filter will last for a couple years.