Filter / Odor issue

[anon0988]

I've got a small closet grow going with a passive intake setup. My exhaust system goes Filter->6" vent duct->6" Cool Tube->6" vent duct->6" centrifugal blower (~430 cfm)->vented into another room.

Now the issue is that sometimes the other room it vents into will have some odor in it. The air passage from the filter to the end of the exhaust venting is pretty well sealed, although probably not completely air tight. I already plan on going through and thoroughly sealing the system to prevent that from being a possibility. Is there anything else I can do to help this situation? I had a shipping issue with my fan speed controller so it's currently running full speed. Will slowing it down make much of a difference? Any other tips for eliminating odor with this system?

 

[Cheeb]

Pull through filter.. push through light and out.


You're pulling stink into pinholes in your ducting or somewhere down the line.

 

[Cheeb]

Eh,

Cant edit my post damnit.

The way you have it setup now is giving you negative pressure everywhere up until the fan. You want your room to maintain negative pressure, but need positive pressure in your ducting/reflector to prevent smell from getting pulled in elsewhere.. thus bypassing your filter.

 

[Sativa Dragon]

Cheeb is right you have a hole somewhere in your system, you are one up on me when I started. I started with a air-cooled hood had a lot of leaks, then I went to a cool tube which was better. What you have to do is check the cfm on your charcoal filter and see if your fan has a greater cfm rating. If your fan has a greater cfm rating buy a fan speed controller, Ebay $30 us, slow your fan down to decrease the negative pressure in your system to where your matching the cfm's of your filter. The way I did it is I turned the fan down till the temps in the room reached a desirable limit. This will prolong the life of your filter as well.

Peace

 

[RM - aquagrower]

Yep. What both those guys up there ^ said.

You need to move the fan. Should be: filter to fan to duct to cool tube to duct out of room.

Or you can get one of these http://www.plantlightinghydroponics.com/phresh®-inline-filter-6in-p-4175.html

Good luck and stay safe.

 

[RB56]

First thing is to correct the component sequence ^^^^

I run a small filter/freshener deal called a TrueAir in the room I vent into. Has replaceable charcoal filters. Does an amazing job. Nice to have a backup against little whiffs that might escape.

 

[FlowerFarmer]

Yes.. what they said.

In case it wasnt clear though. You want it like this.


-> Filter -> Fan -> Ducting -> Cooltube -> Ducting -> Out

 

[Granger2]

I would use this set up.
-> Filter -> Ducting -> Cooltube -> Ducting -> Fan -> Out
Leaks will become irrelevant [for odor], fan will pull better. Good luck. -granger

 

[vindiesel]

Or get a vaportek 4000..

 

[Iffy]

Hi,
Just a thought but I saw a new gizmo on Ebay that looked interesting. A section of ducting with a hole in one side. A perforated cage was let into this hole that received an 'Ona' block. This is a kind of belt & braces approach but could be useful in your circumstance.

 

[FlowerFarmer]

I would use this set up.
-> Filter -> Ducting -> Cooltube -> Ducting -> Fan -> Out
Leaks will become irrelevant [for odor], fan will pull better. Good luck. -granger

I think you are mistaken. Leaks do not become irrelevant in that configuration. You've got suction happening in a length of ducting/cooltube after the filter. Might be OK if everything is 100% sealed using rigid ducting, but not normally how people are running it. Flex ducting will develop pinholes in it and this configuration would allow smell to be sucked out.

That is what he is currently doing and has odor issues... unless I'm mis-reading something.


By pulling with the fan down the line like that he is potentially pulling in smell through any leak in his ducting or cooltube after the filter/ before the fan. This maintains negative pressure within the ducting and cool-tube.. and will suck smell out if there are any leaks.

I know it's best to pull for the sake of performance and efficiency, but think it's better to pull through the filter and push through everything else to ensure you are maintaining positive pressure within the duct work... pushing out heat if there are any leaks as opposed to sucking smell out.

//


Vaportek is a good recommendation.. however I'd suggest using it in conjunction with a scrubber setup.. as opposed to instead of. Best to be proactive in these areas.. overkill is good.

 

[Jnugg]

Any air the fan PUSHES will be positive pressure pushing any stinky air out an pinholes in your ducting.With the fan at the end of the run all air is under negative pressure thetefore pulling air through any pinholes. Try to find your leaks (this is another reason I prefer insulated ducting).

 

[FlowerFarmer]

Not if that air being pushed has already been scrubbed.


If you're pulling through the filter and pushing through everything else you would yes; be creating positive pressure in the ducting and pushing air out of any pinholes. This air however would now be cleaned as it has already passed through your filter.


With the fan at the end of the run you are creating a negative pressure environment in the ducting itself. Smell can and will get pulled into pinholes and be exhausted from your space. If you've got your filter at one end and your fan pulling at the other..you've got that area in between under negative pressure sucking in unfiltered air.

This is why I prefer to pull through my filter & push through the remaining ductings/lights/etc. I agree with wanting negative pressure in the grow room, but I'd prefer positive pressure in my ducting. I'd rather risk blowing some hot air back into my room then suck unfiltered air out.

How I would do it to eliminate all chance of odor.
--> Filter --> Fan --> Ducting --> Cooltube --> Ducting --> Out


You guys are are suggesting this which will lead to smell leakage if there are any leaks.
--> Filter --> Ducting --> CoolTube --> Ducting --> Fan --> Out

^if you've got leaks anywhere I've labeled in red you will have odor issues. Smell would be getting sucked into these leaks and escaping in front of the filter. This is why I believe it is important to run your fan ON your filter.. or very close to it with no possible leaks in between.

 

[RB56]

Not if that air being pushed has already been scrubbed.


If you're pulling through the filter and pushing through everything else you would yes; be creating positive pressure in the ducting and pushing air out of any pinholes. This air however would now be cleaned as it has already passed through your filter.


With the fan at the end of the run you are creating a negative pressure environment in the ducting itself. Smell can and will get pulled into pinholes and be exhausted from your space. If you've got your filter at one end and your fan pulling at the other..you've got that area in between under negative pressure sucking in unfiltered air.

This is why I prefer to pull through my filter & push through the remaining ductings/lights/etc. I agree with wanting negative pressure in the grow room, but I'd prefer positive pressure in my ducting. I'd rather risk blowing some hot air back into my room then suck unfiltered air out.

How I would do it to eliminate all chance of odor.
--> Filter --> Fan --> Ducting --> Cooltube --> Ducting --> Out


You guys are are suggesting this which will lead to smell leakage if there are any leaks.
--> Filter --> Ducting --> CoolTube --> Ducting --> Fan --> Out

^if you've got leaks anywhere I've labeled in red you will have odor issues. Smell would be getting sucked into these leaks and escaping in front of the filter. This is why I believe it is important to run your fan ON your filter.. or very close to it with no possible leaks in between.

This is exactly right. Anything else risks exhausting unfiltered air. With the fan on the filter you may leak filtered air back into the room, but that is never a problem.

 

[Bobbo4200]

I run mine, Filter-Ducting-A/C Reflector-Ducting-Exhaust fan-outside.

 

[RM - aquagrower]

I run mine, Filter-Ducting-A/C Reflector-Ducting-Exhaust fan-outside.

Having dealt with quite a few ventilation problems out in the real world (read: in my day job), I like to use a "smoke test" to verify proper air flow. Since I am a cigarette smoker, I use a cigarette but incense or a joint would also work.

I suggest that you hold a lit cigarette near the glass on your AC reflector and watch the smoke. You're probably gonna see it get sucked into the reflector with the configuration you have listed.

This will indicate that you have un-filtered (read: stinky) air being exhausted "outside", being that AC reflectors are not very "air-tight".