Formula for determining proper carbon filter/fan for an room scrubber? 13'x13'x8'

[Citizen024]

am trying to figure out what size filter and fan I need to scrub my room. Not for heat exhaust too, just to sit and clean.


I hear you want to move them faster as scrubber, and that you can get away with a smaller filter then you would for exhaust.

I have 1352 cubic feet (13x13x8) room. I am going to round that to 1500. If I use my 6" fan at 300cfm I am looking at a exchange every 5 mintues= 12 times as hour. If I upsize to an 8" now I am looking more at the 750-850 cfm range, exchanging every 2 minutes= 30 times as hour. With that large fan, I can use a speed controller to quiet it down by slowing that rate.

How many times an hour does the scrubber need to exchange the room to be effective?

It would seem if I could get that number I could figure out the rest. Then I can determine the fan size, and then determine which filter runs at the speed that allows it to exchange the room at the right number of times per hour. There is a sheet that shows what fans fit what filters. And the filters are all rated for a max/min speed.

I have seen some crazy complex math for determining sizing if your building your own. Most of these formulas are not for scrubbing, but for exhausting in addition (which generally runs slower through the filter, and you use a larger filter).

Arggg. . . none of the shop guys seem to know- they just say "go big" and oversell.

 

[LlamaSchool]

Many carbon scrubber manufacturers rate their scrubbers for minimum, maximum, and recirculating CFM rates. I know it is on all Can Filters.

 

[Smokerman]

]PROfilter Reversible Carbon Filter 150 (12" 1300 CFM)
[SIZE=-1]Print This Page[/SIZE]

TIP Recommended fan: Vortex Inline Fan 12" 1140CFM.


Most can-type air filters utilize 50% of the carbon available by only filtering through the top section of the carbon filter, leaving the bottom section unused. PROfilter uses an innovative patented design allowing the user to reverse the filter, benefiting from the use of 100% of the carbon available and effectively extending the units’ life span.
Manufactured with only the finest TC940 virgin 3mm grain sized carbon, PROfilter effectively removes 99.5% of odors.
Rated for a continuous worry-free operation, PROfilter can be used for commercial or residential applications.
Technical specifications:
+ CFM: 1300
+ Flange: 12"
+ Carbon Weight 100lbs.
Approx. Room Size: 12' x 12' x 8'

 

[Citizen024]

A 12" fan? 100lbs of carbon? That is friggen huge. That sounds like maybe for an exhaust, but not for a sitting recirc filter. Probably a lot bigger then needed.

I found a great simple how to with a clothing hamper:
http://forum.grasscity.com/general-indoor-growing/248630-building-carbon-filter.html

He removes 5kw worth of smell with a simple 4" blower, and the model could run a 6 or larger. Go figure.

"Many carbon scrubber manufacturers rate their scrubbers for minimum, maximum, and recirculating CFM rates. I know it is on all Can Filters."

I looked at them yesterday. Yes they and many other filter companies provide that info. BUT the key misses piece: how many times an hour do you need to have it pass through the filter?

The min/max and flow rate are key to matching a fan to a filter size wise, but don't help you select the right filter to room size. Unless you know "I need my room to exchange X number of times".

 

[FunkBomb]

I think an 8" fan and 8" Can filter would do the trick fine, especially if it's always running.

-Funk

 

[Citizen024]

That's what i am thinking. I had it down to a 8x40 as being the most likely. I am tempted to build the clothing hamper one cause its half the price, and I can make it the same size easy enough.