Ventilation, re-circulation or double filters

I'm setting up my grow space which is 24" x 24" x 48". I'm building a box that will have passive vents, all joints fully caulked/sealed and I'm thinking about the odor control/ventilation options.

I'm thinking one of a couple things...

1) have a carbon filter in the box routed to a fan mounted on the back of the box then exhaust that back into the box with another carbon filter thus re-circulating the air back into the box to be scrubbed yet again or..

2) Carbon filter in the box, fan mounted outside the box with another carbon filter mounted on the end of the fan also outside the box or

3) mount the fan filter combo inside the box to be vented outside the box like I have in the past.

Something is telling me a double filter system might be better at odor control but the fan may need to be beefed up a bit to handle the pulling then pushing...

Any thoughts/advice is welcome!

giantsfan24 said:

I'm setting up my grow space which is 24" x 24" x 48". I'm building a box that will have passive vents, all joints fully caulked/sealed and I'm thinking about the odor control/ventilation options.

I'm thinking one of a couple things...

1) have a carbon filter in the box routed to a fan mounted on the back of the box then exhaust that back into the box with another carbon filter thus re-circulating the air back into the box to be scrubbed yet again or..

2) Carbon filter in the box, fan mounted outside the box with another carbon filter mounted on the end of the fan also outside the box or

3) mount the fan filter combo inside the box to be vented outside the box like I have in the past.

Something is telling me a double filter system might be better at odor control but the fan may need to be beefed up a bit to handle the pulling then pushing...

Any thoughts/advice is welcome!

Click to expand...

the idea will not work well
1 carbon filter in the area then ducting then fan then ducting to ejection point

that is all there is to it ......the air will be sucked out and dumped outside with no smell to it ....the smell from the plant will be contained in the grow area from the negative pressure caused by u sucking and dumping the air outside ....the temp in the area in controlled by the suction of cool Co2 rich lnto the area tho the low passive vents

the idea u are thinking about is called air polishing is it done to remove the smell from the room during drying or when adding in CO2 tho a burner/tank set up


if u are worried about smell outside the grow area just get a filter system with a ozone gen .........after u open the area do the work and shut it smell will be around for a bit ....turn on this run it for 20 mins and turn off no one will smell anything worked for me for 5 years
http://www.ebay.com/itm/New-Aerial-7-Stage-Air-Purifier-UV-Ozone-Generator-Ionizer-Alpine-Cleaner-Cherry-/351048151781?hash=item51bc19b2e5:g:qlYAAOxyaTxTSv36

I'm in a similar situation but with a couple more feet... I'd hate to do #3 with only 48 inches.

The one thing that kept me from having the fan outside of the box is sound. I'd do #1 if sound isn't a problem. My only problem with #2 is that I very rarely see people try to do this. I imagine if one carbon filter misses a smell, then the second is highly probable to do so. I know that's not really a high standard of evidence, but worth considering.

justugh said:

the idea will not work well
1 carbon filter in the area then ducting then fan then ducting to ejection point

that is all there is to it ......the air will be sucked out and dumped outside with no smell to it ....the smell from the plant will be contained in the grow area from the negative pressure caused by u sucking and dumping the air outside ....the temp in the area in controlled by the suction of cool Co2 rich lnto the area tho the low passive vents

the idea u are thinking about is called air polishing is it done to remove the smell from the room during drying or when adding in CO2 tho a burner/tank set up


if u are worried about smell outside the grow area just get a filter system with a ozone gen .........after u open the area do the work and shut it smell will be around for a bit ....turn on this run it for 20 mins and turn off no one will smell anything worked for me for 5 years
http://www.ebay.com/itm/New-Aerial-7-Stage-Air-Purifier-UV-Ozone-Generator-Ionizer-Alpine-Cleaner-Cherry-/351048151781?hash=item51bc19b2e5:g:qlYAAOxyaTxTSv36

Click to expand...

Yeah I wasn't sure it would work either as I could not see how air would be refreshed but I thought I'd ask. Thanks for the response @justugh

staygreener said:

I'm in a similar situation but with a couple more feet... I'd hate to do #3 with only 48 inches.

The one thing that kept me from having the fan outside of the box is sound. I'd do #1 if sound isn't a problem. My only problem with #2 is that I very rarely see people try to do this. I imagine if one carbon filter misses a smell, then the second is highly probable to do so. I know that's not really a high standard of evidence, but worth considering.

Click to expand...

I've got the plant height thing figured out so I don't think it's a problem that way..Plants are 4" off the floor, pots are 9" to the top rim and a scrog will be installed after LST about 5" above that and laterally do I go. That gives me about 20" of grow space which is plenty. I love small space growing.

The pic below wasn't scrog'd but was LST'd and it only got 22" before chop.

I have a similar sized box. A little bit larger. I built a chamber on the side of it for filter to sit in. Was getting in the way of lighting.