Lex Dysic said:I'm sorry...I've looked at for quite awhile now... that formula doesn't make any sense to me.
I've got a 4" dayton blower rated at 265cfm.
I want to use a 4" core and 6" outside.
How long should the filter be??
Thanks much!!
Lex
I'd like to give credit to SunIsShining for being the originator of this design, It's the exact same one that SunIsShining posted on OG that i've been using for years (I remembered his name partly due to it being my favorite Bob Marley song. ).
I made one that has a charcoal chamber 16" long and 8" diameter, it works great with my 4" 19 watt Fantech FX4 inline fan hooked to a 1000 watt HPS.
One modification I made was to take a large air filter, cut out the paper box part surrounding it, and use duct tape to secure it around the outside. This prevents the carbon from sagging out and also extends the life of the carbon greatly by preventing dust infiltration.
Nice writeup Durban Poison... and a big thanks to SunIsShining!
Not trying to be a neg here but I thought the recommended thickness of the carbon was 2". Thicker the bed the longer she's gonna last and the more she's gonna filter. So to get a 2" thick wall of carbon around a 4" core you would need to use an 8" shell, yes 8-4=4 but remember your centering the core, splitting the 4" which gives you a 2" perimeter. Wholesale HVAC distributors will have the large size fittings. If you can't find them in the phone book ask an HVAC guy when you see one.
On a side note, I enclosed my carbon filter inside a plywood box with a home return air filter installed, I use the high dollar home filters as a pre-filter to keep the dust out of my carbon. Try this setup, look at how dirty the filter gets in a month and you'll see how much life you just added to your carbon filter. She's been running 2 years and I still don't smell it outside.
Peace