carbon scrubber and exhaust questions

[built2last]

hello everyone got a couple of questions... I am growing in a 3x3x7(I think 7) hydrohut. My question is this...The equiptment i currently have in the tent is an elf filter > ducting>400w radiant> 4" acitve air fan>out the top of tent. I am currently growing 5 ak-47's that are going into flowering tonight. My problem is I am growing in a basement and I can smell the plants vegging throughout the house. Not super noticable but i can tell. Especially downstairs. I have a good bit of extra ducting between the filter and the light now because the plants are bigger and the light doesn't need to be that far away from the filter and fan. By shortening the ducting and refitting it to the light will this improve the efficiency of the scrubber?

Also, the tent has very good negative pressure. Tent is sucking in. Maybe to much. I am using the two holes above the screens on the bottom with ducting creating passive intakes. Am i correct in assuming that too much negative pressure can cause the fan to be not as efficient resulting in smell?

 

[built2last]

tryin to keep it alive...anyone???

 

[built2last]

well this is what i'm thinking as of now. filter>fan>outside tent. Use another 4" fan to cool the hood. Any thoughts???

 

[csharper]

didn't you say you had a light seal problem on your reflector in the other thread? if so, and your filter was the first thing in the chain, instead of the last, then yeah, of course it smelled. Basically you want the filter right before or right after the exhaust fan, I think you have the idea in this last reply.

Maybe you can't go that high - in which case, you need all the ductwork to the exhaust sealed - nothing can leak in once filtered.

 

[built2last]

the reflector is all sealed. I think my problem is I don't have enough power to efficiently filter air and cool a reflector all on one 4" fan. So what i am thinking is to get another fan solely for the reflector and vent that also. What do you think? By getting a larger fan would mean an increase in noise right?

 

[csharper]

I dunno, it's kinda hard to debug your equipment remotely - but all I can really offer is you need to determine 100% if a) your odor problem is coming from the exhaust or b) is just leaking out of the tent.

If a) then your fan is pulling odor into the ducts after the filter. Check the seals again.
If b) then your fan is insufficient to maintain negative pressure, (ANY constant pressure under 0, I would think sufficient)

I don't see how moving more air through the filter is going to make it work better - work harder maybe.

Bigger fan can move the same amount of air with less rpm = quieter. Also not using your fan at full rpm = more pressure (but less airflow). Use a speed control to knock it down from full speed. My 8 inch vortex at 50% forcibly flaps my intakes and is no louder than a window ac unit.

 

[hazy]

You say that you are venting out the top of the tent and into the basement that the tent is in?
Seems like your fan is keeping the neg pressure well if the sides of the tent are sucked in. Try blowing out through the filter.
in through the hood > through a duct > through the fan > through the filter. That way the only seal that really matters is the fan to filter. After that, you might need a better filter.

 

[caljim]

And the answere is...

And the answere is...

If the smell is getting past your filter and you have good negative pressure, then either the air is passing through the filter too quickly for the carbon to be effective ( buy bigger filter or slow down fan) and/or your carbon is spent and needs to be replaced (buy new filter).

 

[built2last]

well i disconnected the light from the ducting and assembled the filter directly to the fan. Much better. My thoughts are the 4" fan is only rated at 165cfm and when pulling through the light and the filter i was losing to much power causing the filter to be ineffective. There were no leaks and the light was completely sealed. Not sure if it would be better to get another 4" fan for just the light or a bigger one for everything? What you guys think?

 

[In Vino Veritas]

well i disconnected the light from the ducting and assembled the filter directly to the fan. Much better. My thoughts are the 4" fan is only rated at 165cfm and when pulling through the light and the filter i was losing to much power causing the filter to be ineffective. There were no leaks and the light was completely sealed. Not sure if it would be better to get another 4" fan for just the light or a bigger one for everything? What you guys think?

bigger fan for everything..

[TENT: Scrubber/Duct/Hood/>Fan>] >>outside of tent..

this way you create negative pressure and all the air is forced to go through the scrubber and out of the tent. you need to make sure its all sealed well.

how big is your scrubber??

 

[built2last]

its one of the small elf filters

 

[EvilTwin]

the reflector is all sealed. I think my problem is I don't have enough power to efficiently filter air and cool a reflector all on one 4" fan. So what i am thinking is to get another fan solely for the reflector and vent that also. What do you think? By getting a larger fan would mean an increase in noise right?

Hi Btl,
I've never set up a tent, but more then a few grow rooms. Mostly I wanted to address the issue of noise. If you do have to go up in size, you may want to consider a super stealthy Panasonic Whisper Line of fan. They are amazingly quiet and vibration free.

I use two of them, one for exhaust and one intake in a 10x11 foot bedroom grow space. Here's a shot of one. They're squirrel cage design and a bit bulky so you may have to find a way to mount it outside your tent. Just a thought...
ET

 

[built2last]

Thanks for the reply's everyone. Here is where I stand.

After hooking the filter directly up to the fan I have come to the conclusion it was a total waste of time and a pain. I guess I could get a speed controller for the filter but after reading a bit about peoples experiences with these filters it seems as though the general consensus is they're garbage. Not enough carbon to effectively kill odor. When I had it hooked up with the light the tent still had good negative pressure but the filter was ineffective so not sure if a speed controller would help. I just started 12/12 on sunday and if I was having this problem in veg I can only imagine what I will get in flower. The air coming out the tent after supposedly being filtered still has an odor. I spoke with the guy at the hydro shop he said that I can't have the filter hooked inline with the light because I would be using more that half the power of the fan for the filter and this would be why the filter was not working properly. Hence the reason I switched the filter back to directly on the fan (which is what he said to do and get another 4" fan for the light). Maybe he's just trying to sell me another fan? But anyway it's still not working. Any suggestions? Does anyone have any experience with these elf filters in a tent?

 

[EvilTwin]

Btl,
No experience but one comment. I've heard of people using a large scrubber and fan that's not even attached to the tent. Just in the same room. So if you can't get something to work with your tent, buy a decent sized scrubber and fan and deodorize the whole room. Just a thought...

I use two large scrubbers in my room and it cleans the air in my whole house. No ganja smells and nice clean air to breath.
ET

 

[built2last]

Hey eviltwin

I'm trying to keep everything inside the tent for pseudo stealth reasons. Your idea makes sense but not what I'm looking to do. Thanks though

 

[EvilTwin]

Hey eviltwin

I'm trying to keep everything inside the tent for pseudo stealth reasons. Your idea makes sense but not what I'm looking to do. Thanks though

OK, sorry didn't know that. If your scrubber isn't doing the job, I see little option but to get a larger one.

There are two different kinds of carbon. You want vapor phase that's designed to work in air and not water. But if your scrubber is new, it most likely has the right stuff. Good luck to you...
ET

 

[built2last]

Thanks ET

Yea it just has been a pain trying to get everything dialed in. Thanks for the advice and I think thats what I'm going to have to do.