Exhaust Questions

I currently have a 5x5 grow room with grow log that can be found at:

http://boards.cannabis.com/grow-log/...lo36-grow.html

I have several questions but the first is... is my Charcoal Filter in the right place?

I have 1 fan that has to run the exhaust.

I am using some ductwork to vent my floor vent for the central air of my house into the tent for fresh air.

I am using a 440 CFM 6" fan through a goblin charcoal filter for exhaust, with the charcoal filter place in the tent inline before the fan. I have heard that this greatly restricts airflow but seeing as though by tent is only 5x5x7 (175 CFM) I would assume 440 CFM x 3-5minutes would be plenty even if restricted by as much as 50%. Is there a better method?

Lastly, I have heard that Charcoal filters are activated by heat, since I am using LED for my main light source and Florsecent for 4-6 Hours a day I should be generating any significant amounts of heat, will the air still be hot enough to activate the carbon or should I consider another means of odor control?

Hi SunLake,

I have a carbon filter also, but have yet to use it on any of the 3 grows I have done so far, so cannot help much aside from saying you probably wont need it until your plants are at least a few weeks into flower. I doubt your plants will give off any noticable odour until this time. Looks like you have spent a fair amount of money, hope you manage to dial in the setup! :thumbsup:

Quote:

---

Originally Posted by SunLake

I currently have a 5x5 grow room with grow log that can be found at:

http://boards.cannabis.com/grow-log/...lo36-grow.html

I have several questions but the first is... is my Charcoal Filter in the right place?

I have 1 fan that has to run the exhaust.

I am using some ductwork to vent my floor vent for the central air of my house into the tent for fresh air.

I am using a 440 CFM 6" fan through a goblin charcoal filter for exhaust, with the charcoal filter place in the tent inline before the fan. I have heard that this greatly restricts airflow but seeing as though by tent is only 5x5x7 (175 CFM) I would assume 440 CFM x 3-5minutes would be plenty even if restricted by as much as 50%. Is there a better method?

---

More information on the fan would be helpful. A 6" Vortex fan is an entirely different beast than a 6" duct booster. If you are using a centrifugal style, you're all set. It'll move more than enough air. If you have a duct booster type, airflow *could* be marginal when drawing through a charcoal filter. I'd run the set-up for a couple days to get an idea of internal temps using your lighting configuration.

I hang the fan/filter from the top of the tent, as high as possible.

Quote:

---

Originally Posted by SunLake

Lastly, I have heard that Charcoal filters are activated by heat, since I am using LED for my main light source and Florsecent for 4-6 Hours a day I should be generating any significant amounts of heat, will the air still be hot enough to activate the carbon or should I consider another means of odor control?

---

I've never heard that before. I have seen folks bake carbon filters to remove excess moisture, but they work just fine at normal temps.

HTH

I'm using a vortex fan, 440CFM ... I'm using LED lights too, the purpose of the exhaust is mostly just to remove any stale air but also control the smell of the GB during flowering.

It's not activated by heat.... It's actual name is "active Carbon" its extremely porous and absorptive. Heat isn't required. The only way to properly set it up is so that the only air leaving the space goes through the fan that pushes to the filter. You can put the filter in front or behind the fan as long as your ducting is sealed. I put mine at the end after the fan becuase i use a cage fan and its better at pushing air then pulling. Fans vary in static pressure, you can do a test run to see if one is really better then the other, one way sucks, one way blows, put ur hand by where its either sucking or blowing and see which one has more air flow, I think generally most fans are more efficient at making pressure"blowing" then trying to suck air. The filters are actually set up to have the fans suck air through them becuase they have a dust cover on the outside, which would be useless if it was blowing.