Carbon Filters: Efficiency/Effectiveness?

[home.grower]

Hello readers,

I have a query, who wants to help?

So I've been to the grow-shop and picked up a copy of the latest Urban Garden Magazine. I'm smoking a joint and reading an article called 'A Mind Blowing Guide To Ventilation - Part Two'.

Without further ado:

'... Blowing air into a carbon scrubber tends to give an even pressure across the entire internal surface, which leads to lowest average velocity through the filter and therefore best smell reduction. It seems that sucking will draw most of the air through the carbon that is closest to the outlet. This is because the pressure drop across the carbon is greatest where the scrubber meets the ducting. Due to the large momentum of air being thrown out of a duct when you blow in to it, a larger amount of pressure should be available at the far end and should balance out more evenly across the surface. This should result in a slower average speed through the filter material and better smell removal...'
*Page 16 Nov/Dec 2007 UrbanGardenMagazine 004

​

What do the friendly readers of the forum make of this statement?

Does anyone use a carbon filter in a direction other than sucking?

I've added a lil diagram that explains what I THINK (edit) the author is on about. I'm wondering if my filter will actually be more effective in the other direction.

Actually, are carbon filters designed to be bi-directional?

thanks!

 

[home.grower]

No opinions out there?

 

[rmax]

Home,

Your drawing is correct.


"Bi-Directional"

Reversible carbon filters exist. I did a google search. I came up with the ProFilter Reversible Carbon Filter - 50.

"
Most can-type air filters utilize 50% of the carbon available by only filtering the top section of the carbon filter, leaving the bottom part unused. PROfilter uses an innovative patented design allowing the user to reverse the filter, benefiting from the use of 100% of the carbon available and directly extending the unit's lifespan.

Manufactured with the finest TC940 virgin 3mm grain sized carbon, PROfilter effectively removes 99.5% of odors. Rated for continuous worry-free operation, PROfilter can be used for commercial or residential applications.
Requires choice of flange."

 

[Micheal Kelso]

I keep mine on the exhaust. Mine blows into the filter - seems to work best this way and also is more dampened making it more quiet.

I guess I never thought to suck air through it...

 

[butter111]

if u never sucked air through it how do u know it works best the other way?
and what do the fan mfgs recommend?

 

[Micheal Kelso]

I guess I meant that it works good that way, not best.. my comparison comes from just running the fan w/o a filter (real loud) and then with the filter..

The one I have came assembled with the can fan blowing into the filter. I looked at the documents that came with it and it doesn't say anything about reversing it so I guess it is only meant to work with the air blowing into it.

 

[saine420]

I suck it through. Maybe ill try to blow it through. I thought to blow it through, but I heard sucking was better.. First grow I smelt nothing. This one I smell a little, maybe before I buy a new one I'll try to blow through. I heard blowing it through reduces the smell in the place where you exhaust, but your room itself and the surrounding areas smell stays. With the filter in my room sucking the room air through and out you have to put your face to the bud to smell. I will try though.. Thank you!!

 

[home.grower]

'... Reversible carbon filters exist. I did a google search. I came up with the ProFilter Reversible Carbon Filter - 50...'

I'm searching google using the search string 'bi-directional carbon filter' and I'm not quite hitting the nail on the head. Can u post your search string please so I can see what google comes up with, or a link to the manufacturer.

I wonder if the length of a filter and the diameter of the opening have significant impact on the overall efficiency of carbon filters.

My current filter is only around 19" in length and 9" diameter and 6" opening, but my fan is a 8". Am I likely to increase the efficiency of my filter by using a larger extractor?

thanks

I keep mine on the exhaust. Mine blows into the filter - seems to work best this way and also is more dampened making it more quiet.

I guess I never thought to suck air through it...

I've seen a setup featured on the urban grower dot com website where a grower has a dual scrubber in a grow room. I recall 2 huge fans operating in the same direction and 2 huge 12" carbon filters either side of the room. One was sucking while the other pushed air through the carbon. The reporter stated that he could hardly smell the tens of plants in full bloom. Have you seen this setup and I wonder if I put my existing or a second filter inline on the air-out if this will be just as effective

thanks

if u never sucked air through it how do u know it works best the other way?
and what do the fan mfgs recommend?

Very good question. I don't think I would have thought to ask it, but I'm now on-guard.

thanks

I guess I meant that it works good that way, not best.. my comparison comes from just running the fan w/o a filter (real loud) and then with the filter..

The one I have came assembled with the can fan blowing into the filter. I looked at the documents that came with it and it doesn't say anything about reversing it so I guess it is only meant to work with the air blowing into it.

Who makes your fan and filter?

Thanks all for replying.

 

[home.grower]

... I heard blowing it through reduces the smell in the place where you exhaust, but your room itself and the surrounding areas smell stays. With the filter in my room sucking the room air through and out you have to put your face to the bud to smell. I will try though.. Thank you!!

Same here.. Although from time to time and especially after watering these ladies do let off their sensual aroma.

And rmax, its ok, I had my cannabis hat on and wasn't searching as a searcher should... I've found and I'm about to do a lil reading.

thanks

 

[Micheal Kelso]

I bought it used on Craigslist.. the brand is EcoPlus Carbonaire. I don't know the model though since I bought it used.

After looking at the manual that came with it.. I am starting to think I have been running it backwards... The person who had it before me just had it set up with the fan blowing in so I thought that is how it should go.

I looked at some similar ones online and they all have the fan sucking in the pictures...

It makes sense because by blowing into mine, I don't even need the prefilter on the outside because it is only slowing down my CFM.

Now you got me thinking I should make mine suck in, the fan just flips over no problem....

 

[home.grower]

Very interesting post there rmax. After a bit of googling I now see what you are talking about. Bit I wonder what the design creators implemented to give greater efficiency?

 

[tahoe58]

mine is on the exhaust....and is very effective....but then that is the way my system was designed to function as well....so I can't speak to the other approach.

 

[home.grower]

I bought it used on Craigslist.. the brand is EcoPlus Carbonaire. I don't know the model though since I bought it used.

After looking at the manual that came with it.. I am starting to think I have been running it backwards... The person who had it before me just had it set up with the fan blowing in so I thought that is how it should go.

I looked at some similar ones online and they all have the fan sucking in the pictures...

It makes sense because by blowing into mine, I don't even need the prefilter on the outside because it is only slowing down my CFM.

Now you got me thinking I should make mine suck in, the fan just flips over no problem....

You have me thinking too. If you Non-Bi-Directional filter works in a direction it shouldn't, then maybe many or all filters can be used in either direction. There are of course other questions that need to be brought up before one changes their setup, but if it doesn't matter if the can is on the in or out, and on the out is quieter, then this is ideal info for those how suffer with noise pollution from their indoor garden.

My setup is quite noisy. I can't hear the front door knocking from inside the grow space. I have a room within a room type setup, making my garden very much self contained. I do have the option of adding another filter outside the grow space to dampen the sound if it was an effective measure.

 

[home.grower]

mine is on the exhaust....and is very effective....but then that is the way my system was designed to function as well....so I can't speak to the other approach.

Do you know who manufactured your filter? I'm trying to establish as many ways as possible these things can be used regardless of what the manufacturers say.

What size filter(s) length; diameter; and duct opening do you/we all use?

thanks

Does Anyone Use A Silencer!?

 

[bobandpaul]

thinking of purchasing a phat filter ...anybody on here know anything about these types of filters?

 

[email468]

I think i can help - the reservable carbon filter is so you can flip the carbon filter the other way to ensure you've used all the filter regardless of whether you are sucking through or blowing out.

The carbon filters are designed to be on the end of the exhaust (so you are blowing air through it) BUT a lot of growers suck the air through that way you can put it on the inside of your box to keep it more stealthy. That way - there isn't a huge filter sitting beside your "wardrobe".

 

[home.grower]

I think i can help - the reservable carbon filter is so you can flip the carbon filter the other way to ensure you've used all the filter regardless of whether you are sucking through or blowing out.

The carbon filters are designed to be on the end of the exhaust (so you are blowing air through it) BUT a lot of growers suck the air through that way you can put it on the inside of your box to keep it more stealthy. That way - there isn't a huge filter sitting beside your "wardrobe".

So filters ARE designed to be blown in to then? And sucking is just a choice on the growers part?

 

[email468]

So filters ARE designed to be blown in to then? And sucking is just a choice on the growers part?

that is my understanding but admittedly my understanding is very limited

you could contact the manufacturer of any filters you are considering and ask them.

 

[Heruk]

whats a good yet cheap filter?

 

[LoudBlunts]

whas your price range?