Ventilation Questions

[skinzilla]

How much does a carbon filtre decrease inline fan performance? I'm thinking of getting a 6" fan(440 CFM) for my room that's 880 cubic feet. Does the 6" fan have to "work harder" to pull the air through the carbon filtre? Will it still be sufficient for my room? Also, what size carbon filtre do I need for a room that size(880 cubic feet)?
Thanks.

 

[busty]

The easy way to figure it out is that you want the air in your room refreshed about 3 times every minute.

If you have an 880 cubic foot room you'd need about a 2640 cfm exhaust fan.

Your plants need the air refreshed once or twice a minute to make sure that there's enough CO2. With replacing air 3x a minute we're exhausting quite a bit of heat.

If you air cool your lights (with an inline fan exhausting at a rate of .3 to .5CFM per watt) you can drop the CFM level of your cab exhaust to a level of 1760 CFM (refreshing your room's air twice a minute) if you'd rather do it that way. It's a little easier to manage temps if you air cool your lights in a space that large.

Now, you'll need a properly sized carbon scrubber. If you go too big... you will have no problems. If you go too small your contaminated air won't have enough contact with the carbon and you'll end up with smell problems. You'll find that carbon filters are rated based on CFM, so once you figure out your cooling you can find a matching carbon filter. A nice thing about exhausting your lights separately is that you can get a much smaller scrubber because you're not pushing any more contaminated air than you have to.

Best of luck to you.

 

[als0me]

couple years ago i saw a post on homegrown420 how to calculate the carbon filter. one says that for 100% air purification, it should be in contact with the carbon for at least 0,1 sec. and thickness of the carbon layer about 1 inch.