Question about Carbon filters and air circulation

Alright guys so I am planning my grow tent setup and I was wondering if I had to vent out the exhaust that is filtered by a carbon filter or if I could recirculate it.

I want the least odor possible.

Thanks!

You need negative pressure in your tent to keep the smell under control. Is there a reason you wouldn't want to vent the hot air out of your tent?

You are describing 2 different things one is a filtered exhaust and the other is a scrubber. I personally have a sealed room I use a big 8 inch fan and a big carbon filter as a scrubber and a small 4 " fan that pushes though 2 carbon filters as a n exhaust, that basically is just going to keep a neg pressure in the area. If you want the least odor do both

Los Reefersaurus said:

You are describing 2 different things one is a filtered exhaust and the other is a scrubber. I personally have a sealed room I use a big 8 inch fan and a big carbon filter as a scrubber and a small 4 " fan that pushes though 2 carbon filters as a n exhaust, that basically is just going to keep a neg pressure in the area. If you want the least odor do both

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Can you notice the smell outside of the room?

Los Reefersaurus said:

You are describing 2 different things one is a filtered exhaust and the other is a scrubber. I personally have a sealed room I use a big 8 inch fan and a big carbon filter as a scrubber and a small 4 " fan that pushes though 2 carbon filters as a n exhaust, that basically is just going to keep a neg pressure in the area. If you want the least odor do both

Click to expand...

So you have a sealed room with a small exhuasting for negative pressure? It's a good idea, I haven't heard that before but I guess as long as it's a small amount and no intakes it would be helpful to stop any leaks.

Calculate your sq footage in the tent by doing the math: L x W x H
Then once you have an idea of the volume of air you want to exchange every few mins look at inline fans that have the capacity you need. It's better to have something more powerful than you actually need and then use a speed controller to adjust it down until you get negative pressure without pulling the sides of your tent in too much. Filtration will eliminate about 98% of smell but in the final weeks some strains can overpower even the best carbon filtration setup. Be sure there's no leaks. I have an unsealed bloom room so the only way could filter it good enough was to use filters on both the intake and exhaust ducting which you could say is recirculated. You should provide a source of fresh air if you don't plan on using co2 tanks; so yes a recirculating type of system will work but you also need a supply of fresh air mixed in.

newguy123 said:

Can you notice the smell outside of the room?

Click to expand...

I run my 2 filter exhaust up 30' though my gas fireplace chimney that runs back down to the fire place 15' that always has at least a pilot light going, the run is at least 30 feet up to the chimney again to the vent in the roof...... No I dont smell nothing.

About the scrubber, buy the biggest filter you can physically lift on your own and use that one. Replace it if you start to smell the room. The bigger it is the longer it will last