# dust filter question.



## BurlyBob (Mar 13, 2012)

I'm building a dust/air filter for my garage shop. It's 30'X30' with 9' ceiling. I bought a 22" fan from Best Buy with a remote control and may put a timer on it so it'll run for awhile after I close down for the night. Here's my question. Is there a recommended distance between the last filter and the fan for the best results? I know that the quality for the filters is serious consideration and that's down the road after I get this thing figured out.

Bob


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## TopamaxSurvivor (May 2, 2008)

I doubt it much matters. Air handlers have filters at varying distances and numbers in the air flow depending on the application.


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## rwe2156 (May 7, 2014)

I don't want to be a kiljoy buts back up a bit because air quality is one of my "things", OK?
The function of an air filter is to reduce the stuff going in your lungs, right?
That means the dust a) has to be suspended in the air b) the fan has to move an adequate quantity to turn over a certain volume/minute and c) the filters have to be high quality down to the micron level.

You don't say exactly what kind of fan this is, but more than likely if its a box fan its not going to have the CFM's tor work very well. By the time you put a couple filters in there, you won't be pulling the air you need to. If you're using this type box fan, you probably need about 4 of them. Check some of the commercial air cleaners' CFM ratings and compare to your fan.

I've seen several guys use rabbit cage fans. A fan from a small air handler would work.
You really need something that's capable of really moving some CFM's IMO.

All this is just my opinion based on common sense and what I've seen guys build.

My point in the first part of post is to stress that air cleaners clean dust out of the air, which means you're already breathing it in to your own dust collector your lungs before it ever gets to a filter suspended 8' in the air.

You still need a respirator, even with an air filter.

MDF is a toxic material, plain and simple. If you're not using a full face respirator when working with this stuff, you're taking some serious risks with your lungs. I even worry now about a lot of the plywood made in China as far as what glued they are using. I know they smell different when you cut into them, so I'm wearing the respirator with the noxious gas filters on now.


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## Finn (May 26, 2010)

Robert is right. Propeller fans are not made to be restricted in any way. Like with any duct or a filter. Squirrel cage fans (Like are in a furnace) are made for this application and a much better choice. I have a smaller shop than yours and have a $190 ceiling hung air handler from Grizzly that filters all the air in my shop every six minutes.


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