I am looking to build an air cleaner for the shop to help protect my lungs, and hopefully get less dust on the wife's storage bins. I picked up an old furnace fan and motor off craigslist for $15, so so far my investment has been minimal. Here are my questions:
1. Will it matter if the unit is on the ceiling, or floor level? (Buddy had suggested I could dual purpose it for a downdraft table as well).
2. Filters best at intake, output, or both?
3. Do I need to duct the output away from the unit to avoid cleaning the same air over and over, or is that not a concern?
I built a downdraft table for my shop. I will try to get a picture of it this afternoon and put it on here. Mine works great. It doesn't get 100% of the dust but probably 90% or close to it. Not sure how good the ceiling mounted ones work so can't help you there.
You can call me anything as long as you don't call me late for supper.
Post by RiverWalker on May 4, 2010 13:42:03 GMT -6
My dad's so-called Ventilation system when I was growing up was a huge fan, I'm not sure what from, it was sorta a squirrel-cage orientation, probbaly at least a foot and a half wide, and the blade portion probably at least that in diameter, probably bigger, mounted in the window well window and hardwired with a setup where it was plugged into one of two(or was it 3?) dedicated sockets for different speeds, and there was a heavy duty switch to turn it on. no filters, and the front door had to be open to let in air when it was on, and when it was on high, it would pull a gust through every open window and door that the air could get in through.
it could clear an unhealthily fumey, dusty basement in like 20 seconds, not to mention bring a nice circulation of fresh air.
for when it wasn't in use, he had a sliding wood door that would close over the opening to the outside.
it made a rather spectacular roostertail of dust, leaves and such out the window well when it was on too.
not exactly helpful but vaguely related and amusing anecdote.
Filter the intake so that the fan doesn't get gunked up. The tan dust cake on the exposed face of an intake filter would provide a simple visual clue when it is time to change the filter.
A furnace blower is going to make such a breeze in your shop that you shouldn't need any fancy exhaust ducting to control local re-flow. You may choose to make an exhaust difuser to control the wind later on, but then again maybe not.
Last Edit: May 4, 2010 16:06:17 GMT -6 by dcarter636
Hang it off ceiling joists,there is a publication for placement for max efficiency somewhere on this old internet that deals with the location of dust makers.
I was going to go the DIY'er route but didn't have the knowledge to size everything.Protection of lungs is a must in COPD illnesses and you should filter down to .3 to .7 microns,kinda hard for a DIY'er to get there.
I would check out Woodtek Air Filtration Systems they have some ceiling units that will filter down to .5 microns............I don't know prices but would guess $350 t0 $400.I don't think anyone should skimp on this equipment,Air Purifiers and Dust Collection are the most important pieces of equipment you will ever have in your shop.
Here are some pics of the down draft table I built using an old air handler from an AC unit.
the next two show the "well" where the dust is captured. I just use a standard 20x20 filter. The Hepa type captures finer dust.
The next one shows some storage that I use on the end opposite where the fan is located.
The next is showing the top of the table where I have a 2'x2' mdf with 1/2" hole on a 1" grid. I originally had a 4'x2' but it works better with only half of that. Lots of air movement going down there and really pulls the dust down. I use it when sanding or using my Foredom tool (Dremel on steroids) which you can see laying just behind the planer.
The last one is the outlet where the air blows out and is covered with a regular vent cover like one would find on a return air vent.
If room allows, I would heartily recommend a down draft table. Mine also doubles as a work table when it is not being used as a downdraft table. It is not real noisy. I can have it on and still hear a normal conversation easily. As you can see I usually leave the planer sitting on one end but it can be removed if I need the whole top for something. I put casters on the bottom and the table top is just a hair under 36" off the floor. It's not fine furniture by any stretch but it serves a purpose. If you don't have enough room I guess the ceiling mounted unit would be a better fix for you.