Can I do all this with one fan?

I need to refresh the air in a 10x10 room. I also need to filter that air. And cool 3 lights.
Is there a fan that can pull through a filter, 3 lights, and then exhaust to outside in a room that big?

Or do I need separate light-cooling circuit and room circuit?

A 12" centrifugal 1000 ish cfm or the mega fantech 12" at 2000 cfm depending on filter drag, duct losses, and ambient temps.

I'm high!

Just opinion, 10x10x8?800 cubic feet. Change air every 5 minutes = 160cfm fan for the room. Add cooling three lights and pulling through a filter you figure 20% more for the filter and 10% per light so add 80cfm to get 240cfm minimum for one fan. You can probably get away with a 6" fan. I've seen them up to 400cfm. I would be worried about the last bulb getting all of the heated air from every source in your grow to cool it. I don't know your ambient temp swings. I would also worry about the humidity in the last two hoods. Just opinion.

warble said:

Just opinion, 10x10x8?800 cubic feet. Change air every 5 minutes = 160cfm fan for the room. Add cooling three lights and pulling through a filter you figure 20% more for the filter and 10% per light so add 80cfm to get 240cfm minimum for one fan. You can probably get away with a 6" fan. I've seen them up to 400cfm. I would be worried about the last bulb getting all of the heated air from every source in your grow to cool it. I don't know your ambient temp swings. I would also worry about the humidity in the last two hoods. Just opinion.

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Thanks for the input!
If I wanted to exchange all the air in the room in 2-3 mins then I would need a fan that is in the 500-600cmf range.....and probably more if I have a 90 degree bend or two and I will be pulling through about 10 feet of ducting (from one side of the room to the other.

is humidity an issue that people are facing in the last light? That makes sense.

If I go for a larger diameter fan to get some extra cfm, then what are the effects of reducing to a smaller size ducting. My lights have 6in opening. So if I go from 10in to 6 in by a reducer??

It might just make more sense to have 2 circuits and 2 fans huh?

Like snaps said, you are asking way too much for just one six inch fan. I was thinking at least eight or ten. Twelve would be good and then some. Go with a six inch only if you want to buy more fans in the future. Imo.

Good to know. I was under the impression that I should keep the fan the same size as the rest of the ducting.
I just want to make sure that I do this right the first time and buy the right stuff (so I don't have to re-buy things).

I just want to make sure that I wont run into problems venting a room that size and cooling 3 lights using just one fan.

Run a 12" galvanized snap seam trunk with 6 or 8" takeoffs for each light, a similar trunk on the other end of the lights goes to a 12" carbon filter.

Duct mastic the seams, especially on adjuatable elbows.

I have a 2050 cfm vortech 12 inch centrifugal fan (which is a monster, pay attention to dimensions) and it wont cool a slightly larger room with 4 non-air cooled lights

Cfm for air changes and temp get thrown out the window with carbon filters, ducting, and intake filters.

If your using air cooled hoods a high powered 12 inch centrifugal should work great.

- Jiji

Carbon filters can take upto 50 percent off airflow. I find it a good idea to just go fucking overkill on fans and if they need dialed down you can. Ive got an 8" centrifugal fan venting thru an 8" filter with a couple 8 inch elbows, then a 6" centrifugal fan cooling 2 600s in cooltubes, then a 5" centrifugal for intake. My room is only 108 cubic feet. Intake air temp is 15c exhaust temp is 24c.
The more jobs you ask one fan to do the less efficient it is. Fans work more efficiently doing only one job. I would reccomend indépendantly cooled lights with their own air supply ( not hot humid grow room air) tho mate. Much easier to maintain a stable environment imo.

PorterRockwell said:

I'm high!

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me too.

docter said:

me too.

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Me 3

Cost may be a factor also. Them big fans and ducts cost a bunch. It may pay to go with dedicated smaller fans, for cooling, filtering, and venting.. I would work this out on paper too see which option is going to give you the best system for the best price.

Mr John said:

Cost may be a factor also. Them big fans and ducts cost a bunch. It may pay to go with dedicated smaller fans, for cooling, filtering, and venting.. I would work this out on paper too see which option is going to give you the best system for the best price.

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Multiple fans / filters would add up too ime. Probably best to do it right once and only have one filter to maintain.

Note I don't filter, I use an inline ozone generator to cancel odor on my outside bound duct. This saves a lot of duct, and the expendable carbon filter. Low maintenance, extreme reliability.

SnapsProvolone said:

Multiple fans / filters would add up too ime. Probably best to do it right once and only have one filter to maintain.

Note I don't filter, I use an inline ozone generator to cancel odor on my outside bound duct. This saves a lot of duct, and the expendable carbon filter. Low maintenance, extreme reliability.

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The downside with only using one fan-filter to do both the job of temp/humidity control and the job of cooling the lights. This means unless by some miracle hes able to maintain optimum temp/hum and radiant heat from bulbs, all whilst making best use out of air cooled lighting by having them low, hes either going to have optimum temp/hum and burn his plants with radiant heat by not cooling the bulb, or have optimum radiant heat and shock plants with ropey temp/hum.
Plus he would need some huge passive intakes to replenish the air being sucked out. 800'3 is alot of air

Those o3 gennys seem to be the nuts at killin scents like. May well be one of my next investments.

tillygrower said:

I need to refresh the air in a 10x10 room. I also need to filter that air. And cool 3 lights.
Is there a fan that can pull through a filter, 3 lights, and then exhaust to outside in a room that big?

Or do I need separate light-cooling circuit and room circuit?

Click to expand...

http://www.smarthome.com/suncourt-zc106-6-inch-diameter-normally-closed-electronic-hvac-air-duct-damper-with-power-supply.html

Been thinking about ur question and think this may be of use to you, you could tee off some 12" duct with 2 6" reducers. 1 reducer connected to your light duct run and the other connected to one of those electronic duct dampers. Then you could run a duct from outside to the other end of the light duct run making that run closed from grow air. Then fit a filter to the damper and your fan of choice to the 12 inch duct. Imo air pressure would be as equaly important to you as air flow.

Hope this helps, sorry for rambling im not allways very good at getting stuff into words when severely baked.

SnapsProvolone said:

Multiple fans / filters would add up too ime. Probably best to do it right once and only have one filter to maintain.

Note I don't filter, I use an inline ozone generator to cancel odor on my outside bound duct. This saves a lot of duct, and the expendable carbon filter. Low maintenance, extreme reliability.

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I agree - plus it will prob be quieter

kiwipaulie said:

I agree - plus it will prob be quieter

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Yep, much quieter.

Blue brother said:

Those o3 gennys seem to be the nuts at killin scents like. May well be one of my next investments.

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Yep something to look into for sure.