cooling/vent question

[greenblaze]

my room is 9x6x10ft

i had a few questions i was wondering if anyone could help me figure out and i know nothing can be exact but just a good starting point i guess...

1. what size fans im going 2 need for the intake/outake
2. what size fan do i need 2 cool fans
3. what size fan do i need for carbon filter
4. and do i need a fan for each task or can they be combined(like the cooling and the carbon filter or somthin)

just a tid bit of info 2 help...

room is completely sealed off... i have mlyar on the walls...
2 1000w hps lights with air cooled hoods....24 plants(small sog-op)

[cavadge]

Well, I'm just learning all this myself, but I'll share what I've learned so far.

Assuming you're not using CO2...

Your 9X6X10 room equals 540 cu ft. You will want to exchange the air in there every three to five minutes. So you would need a fan between 110 cfm and 170 cfm for that alone.

Used with a carbon filter, you will need a higher output fan, say 250 cfm or more. Carbon filters do pose somewhat of a restriction, so you'll need a higher output fan.

Going by my own experiences, as far as the carbon filter, the bigger the better. I bought a budget fan and filter. The filter isn't doing much of anything. The smell is getting out of the room. The fan is leaking oil after six weeks in service. That stuff is heading for the trash, because the supplier won't make good on the products. And I have to buy something else. This time, I'm going with proven products with a good warranty. So my second time around I'm going with a Can Fan 6 HO (440 cfm) and a Can Filter 66 (31 pounds of carbon, two inches thick).

While I've read where some folks combine cooling HPS lights with their carbon filter all through the same fan, that doesn't appeal to me, and in my case that wouldn't work, so I'm using separate fans.

A passive intake works just fine. Size wise, it should be about double the duct size of the ventilation fan. I'm using a 6 inch fan, which equals about 28 square inches. So you should have an opening of about 56 square inches or more. I started out using a 6X12 register, but as the vent fan in my case has to pull through two adjacent rooms, I upped that to a 12X12 register. That is working fine. The idea is to have a slight negative static pressure, so if there are any leaks in the room, you're pulling air in, not letting the smell out. The vent fan should be pulling air through the carbon filter, then out of the room. Keep duct runs as short as possible, with a minimum number of bends. Your exhaust duct length should be at least three times the diameter of the fan, so with a 6 inch fan, it should be 18 inches or longer.

I'm also running two 1K HPS lamps. Just finished working out the cooling setup for these today. Again, don't scimp here, and forget those inline duct fans. Garbage. Yeah, I wasted 25 bucks on one of those too. I've settled on a standard output Can Fan 6 again, at 270 cfm. The Can Fans come with a 5 year warranty, and given these suckers will be running 7/24 that's important. I'm finding the 1K HPS lights generate a great deal of heat, so exhaust those fans somewhere where that heated air won't get drawn back into the grow room.

You also need to move the air around the room, blowing towards the plants. I went budget here again, will see how that works. An oscillating fan works well. I went with a tower version. I've got two running on the grow, from opposite ends. I ran one, noticed the plants closest to the fan were growing the fastest, so added a second one. Not blowing hurricane force winds at them, just a nice constant breeze. These fans also run 7/24.

Hope this helps you out some. I expect the more experienced folks will be along to offer their wisdom.

[greenblaze]

thanks for the help