fan size for exhaust and carbon filter

[RacecarRandy]

Can anyone help me with the correct size of carbon filter that i need as well as the cfm rating of the inline fan I will need to run the carbon filter as well as air cool the 3 lights? i would like to keep the size of the fan at 8" if possible. i am thinking a phresh or a mountain filter. I will only be using ONE fan to pull air through the filter as well as air cool the lights.


My room is 11'x6' I will be running 3 1000watt lights that will be aircooled.
everything is 8" except for the hole running out the chimney is only 6".
here is a general idea of what i am planning to do, there will be 3 lights instead of two though.

 

[jagle]

cant help you, but shouldnt it be

Light Light Filter Fan Exhaust

in your diagram the dirty, or unscrubbed air would drawn in, if your using an open hood, not if your using a cooltube of course, keep that in mind

 

[jeffadies]

If your hoods are sealed then i would think your diagram would be correct. but i was wrong once before..:)

 

[RacecarRandy]

sorry, I forgot to mention the hoods are sealed. Any idea on the size of carbon filter needed and what cfm fan i would want?

 

[motherlode]

you really should put the 3 lights on their own closed loop and you wont need a filter for the lights

figure about 200 cfm per light - I see an issue with having your fan/lights 8" and your out vent 6" - not good to restrict the flow

ideally you have all the same size fitting for your fan, lights and exhaust

and then you put a passive intake and have a fan just to ehahust the room - put the filter on that

 

[jeffadies]

As big of a filter as you can afford would be my best advice. Your fan size will depend on your filter..I would think that a 700 or 800 cfm fan should do the job. but of course if your filter is rated at 200 cfm max you will not want a fan that big..sorry man i know thats not much of a help.

 

[jeffadies]

Motherloads advice is way better than mine..lol Id go with that.

 

[Darth Fader]

You want the filter cfm rating to meet or exceed the cfm rating of the fan. I got got a 6"x36" Phresh filter and it's bomb. Can't tell you how many cfm you'd need for 3 lights + all the ducting though. Good luck.

 

[jeffadies]

You want the filter cfm rating to meet or exceed the cfm rating of the fan. I got got a 6"x36" Phresh filter and it's bomb. Can't tell you how many cfm you'd need for 3 lights + all the ducting though. Good luck.

Those Phresh filters look very nice. If you dont mind me asking do you have to run it during your entire light cycle to get rid of the smell or can you do it in short intervals?

 

[Darth Fader]

Those Phresh filters look very nice. If you dont mind me asking do you have to run it during your entire light cycle to get rid of the smell or can you do it in short intervals?

Yeah, not too expensive and very lightweight. Got it at greners.com & love it. You can email them the question about your set-up & get a recommendation as far as fan & filter size.

Humidity spikes if you shut down your exhaust when the light go off, so if you're using it for venting you'll want to run it 24/7 to prevent that. I don't think intervals would work at all so even if just for odor control alone, I'd run it 24/7. If noise is an issue, you can run a larger fan on a speed controller and dial the speed down for a quieter overall solution.

 

[motherlode]

yeah 24/7 for fans is a must

if you have to run everything in a line like that your gonna need around 800 cfm fan - I think they make a 790 cfm in an 8" fan - though they might make a bigger cfm 8" - not sure

use the shortest amount of duct with the least amount of corners that you can

you should also have minimum 16" -20" of passive intake so you dont restrict your flow any more (then reducing to 6")

make sure your filter matches the fans cfm

I was checking out those phresh filters - they are crazy light and have read lots of good reviews on them

been using my mountain air for 2 years now and it still works like a champ - mine is way overkill for my room though

when it comes to odor and environmental control overkill is a good thing

 

[jeffadies]

Its awesome that you guys are so helpful. Getting the correct answers make the learning curve alot easier to handle.

 

[RacecarRandy]

thanks for all of the excellent advice everyone!!! you all have greatly helped and have provided me with many useful ideas.

yeah 24/7 for fans is a must

if you have to run everything in a line like that your gonna need around 800 cfm fan - I think they make a 790 cfm in an 8" fan - though they might make a bigger cfm 8" - not sure

use the shortest amount of duct with the least amount of corners that you can

you should also have minimum 16" -20" of passive intake so you dont restrict your flow any more (then reducing to 6")

make sure your filter matches the fans cfm

I was checking out those phresh filters - they are crazy light and have read lots of good reviews on them

been using my mountain air for 2 years now and it still works like a champ - mine is way overkill for my room though

when it comes to odor and environmental control overkill is a good thing

as far as the duct work goes, I have 8 feet going from the fan to the stack and it has a 180 degree turn in it at the end. I know this will greatly effect the airflow. do you think if i were to find a 1000 cfm fan this would be enough for the cooling of these lights and the carbon filter?

 

[RacecarRandy]

I have searched a lot for a fan that is 8" and has a high cfm rating and cannot find any over 700cfm. would i be able to run 2 smaller 500 cfm fans as my exhaust through a 6" hole? here is a diagram to help to understand. my limiting factor is that i cannot modify the 6" hole in the concrete wall and there is no other way to exhaust the air from the room.

 

[f1ydave]

If anything you should be going bigger not smaller. Go to a 10" or 12" inline fan. Just step up the tubing up from 8" to your new size after the lights. Try to make your angles not exceed 45* degrees, 90 at most...180 will be brutal to your airflow. I would place the inline after the bends too. Inlines are designed to create negative pressure, they are not booster fans and cant do positive pressure well.

You want at least 350cfm per 1000w.

 

[RacecarRandy]

if I get a 12" fan will it be safe to run even though the ducting running through the wall is 6" as well as the ducting running out the stack being 6"? also how much will the 6" tubing reduce the cfm the fan can pull?

 

[BakedReality]

What do you think about this....

Attaching a max fan 8 which is close to 700 cfm to the filter pushing. They say a true measured cfm whether there is bends or not is their claim....which is hard to believe for me. I do have a 10" and 8" max fan....I will say wow compared to most in-lines. Then at the point of your 6" reduction have a 6" inline pushing.

Just an idea....looking for input myself, as I will be building some new rooms. I am on the quest for a room without A/C. A/C has such a power draw, but when your going residential and discreet there are limits for everything....

Late

 

[ScrOGer]

I agree with motherload. click here and see what CANFAN has to say about it. well they're canadian, so they will tell what it is all aboot :)

http://www.canfilters.com/canfilters_150.html

there is a list of filters on the left side, click the filter that meets you needs. full specs are listed. then it will tell what fan/s will be efficient for that filter.

done and done.

 

[freegrow]

only 6" exhaust

you could also think about a sealed room and ac with co2 ?and exhausting the lights out the 6" hole might be cheaper dont know :nod

 

[MTM]

I run my filter just like you have it at the end of your lights and its working fine,this is how I allways pull heat and oder out of my room.Im useing the new phresh filters6x24 and its light as hell,half the wieght of can filters .Keep your cfms on your fan about 100cfms under the max cfms on your filter