# Thinking of building a MOAAF



## ryan50hrl (Jun 30, 2012)

So my current shop air filter uses a 600 or so CFM exhaust fan within a box using 20x20 furnace filters. It has 3 stages of filters that get progressively finer. It works fine for the most part, but doesn't really move enough air to effectively clean the shop air. 

Well a few years ago I got ahold of 2 14 inch furnace blowers. So I'm considering building a two compartment air filter, each with a 20x20 filter set. I could turn on one fan for low dust times, and both when I need high levels of dust removal. 


I plan on exhausting the always on fan into the other side of the basement to keep a draft coming back into the shop. And exhausting the second fan back into the shop for simplicity. 


Drawings coming soon....


----------



## jdonhowe (Jul 25, 2014)

Okay, count me stupid- what does "MOAAF" stand for?


----------



## epicfail48 (Mar 27, 2014)

jdonhowe said:


> Okay, count me stupid- what does "MOAAF" stand for?


Mother of all air filters i think. I was curious about that myself


----------



## BWSmith (Aug 24, 2010)

We require "predicted" air movement and velocity here at our shop.Which we have.

How that is achieved,solutions really...have made for very good discussion.With the understanding that forums leave a little on the table,just not like..."being there".But keep reading these types of discussions and you will pick up a tip or 12.

Ryan,ours works fine(ha)...bout the only thing left here is a MOAAF,downdraft.

It's been on the drawing board for awhile.I'm still going to take certain sanding chores outside.This MOAAF-DD...will also function as a rm scrubber,albeit at or near floor level.


----------



## BWSmith (Aug 24, 2010)

"There's no one stupid here"...heavy left leaning pre-school accent.

Could also be..My Own Automatic Air Filter.Translation being,vs slappin down a CC and buying a factory unit...and the attendant,anybody can do it that way.


----------



## ryan50hrl (Jun 30, 2012)

epicfail48 said:


> Mother of all air filters i think. I was curious about that myself



Winner winner chicken dinner!!!


----------



## regesullivan (Jan 26, 2007)

One of the issues might be using 3 "stages". Filters are very restrictive so multiplying x 3 is likely reducing the effectiveness well past the point of diminishing returns from airflow reduction. Maybe try your finest filter with a single simple foam filter (like window a/c units use) and wash or vacuumed the foam daily.

Sent from my SM-G920V using Tapatalk


----------



## ryan50hrl (Jun 30, 2012)

I've been using 3 stages in my current one for a while, with a much smaller blower. One issue I'll have is with wanting to exhaust the air to the other side of my basement, the size of the duct I'd require to do so at 100% efficiency would be bigger than the hole id want to cut in the wall, so some loss of efficiency would be fine. 

I'm considering exhausting one fan to the other side of the basement, and the other back into the shop, for the back into the shop fan I could reduce to two stages if needed.


----------



## regesullivan (Jan 26, 2007)

I have 4 smallish airfilters in my shop. One, is a 200 cfm filter ducted to my hvac return to create negative pressure in the shop. The registers in the shop are taped shut to stop airflow and I keep the doors closed. The two inside doors are cut so there is 2 full inches at the bottom. My goal was to keep dust out of the rest of the house. It works really well.

Sent from my SM-G920V using Tapatalk


----------



## Jammer (Jul 15, 2009)

BWSmith said:


> "There's no one stupid here"...heavy left leaning pre-school accent.


You obviously have't met any of my apprentices.


----------

