Shop Made Air Filter

[Adam Shapiro]

Yesterday's thread on the Jet air filter brought up the comment I see on most of those threads, that it's cheaper to build your own. That always leaves me with a few questions, for those of us without a spare furnace laying around, where can you buy a squirrel cage fan, and how to you determine real world CFM vs the made up numbers given by the manufacturers?

Also, if I've already got a cartridge filter on my dust collector, why not put in a wyee and use that as a secondary filter? I was looking at the roll your own air filter on Wynn's site, and the ambient filters seem to be the same material as the dust collector filters. Couldn't you just run a quieter motor into your dust collector filter system and get the same results? I'm sure I'm missing something obvious here, I just have no idea what it is.

[Jerome Hanby]

I did a Google shopping search for 3 speed squirrel cage fan that tops out about 1200 CFM (to match the jet dust filter) and it looks like one can be had for about $125 delivered. The jet collector is about $340 delivered...

[David Hostetler]

While this won't answer nearly all your questions, here is my meager attempt...

I came up with several squirrel cage fans when working on filtration for my shop. Unfortunately the ones I got were duds. One had a siezed motor, the other the housing was mashed so badly that the fan wouldn't spin. I wish I had kept the fan out of the one with the bad motor and tried swapping motors between the two but that is water under the bridge as it were...

I see them a lot on Craigslist, but honestly, I got mine from crews that were removing old units, swapping new ones in... HVAC contractors have to do SOMETHING with them, and often, they will happily give them away instead of paying to dispose of them...

As far as why not add a wye and just pull through your DC, because you will kill air flow through the rest of your DC system... An ambient filter is in addition to, not an added task for existing dust collection... What you propose MIGHT work, but I really don't want to take those chances...

[Chris Damm]

Used ones are out there. I paid $1 for one at a garage sale and built my own air cleaner. The filters were the most expensive part of the whole build! I didn't worry about cfms because any blower off a furnace is going to have enough airflow for a shop air cleaner. I'm running mine on low speed and have a timer switch so it shuts off after I leave the shop. You do want to have a good DC system to get most of the dust and chips at the source.

[james glenn]

I used a squirrel cage that I got for free from a buddy and installed in into a downdraft table/air filter system. Works great.

But as mentioned before, you can usually get them HVAC guys for nothing to very little. Many even have a stash of them around
the shop. Just have to ask them.

[Chris Tsutsui]

Check Craigslist for air filters before you pull the trigger on the squirrel cage.

Both my Jet air filters were found on craigslist and they were hobby used. I paid like $75 for the JET AFS1000, then like $125 for the Jet 1500.

[William Long]

I built mine about 10 years ago. I only used a single speed and got the motor from Grainger.

[Jeff Nicol]

I worked in the HVAC industry for 28 years before I tore both of my rotator cuffs on the job. That being said we always were doing furnac upgades and most all of the old furnaces just go in the dumpster and any thing that is worth saving is taken off. Mostly new parts or gas valves etc. but the fans were mostly scrapped, so like the others have said if you go to some of the heating shops in your area they should be able to get you one or have some on hand. You may check out some of the scrap yards too to see if they have some as they will take them out and resell them too. When I built mine I used an internal bag type filter as the main filter and a regular 16x24 furnace filter as the pre-filter. Here is the bag type filter

Then I bought a Christmas light remote control for $10 to turn it on and off wirelessly and it is great.

Good luck,

Jeff

[Mike Harrison]

I built mine ten years ago or so, using a free blower I got from the local HVAC dealer. As said any of them are good enough for a shop cleaner.

I built it into the extension table on my TS. I use the sub-micron Hepa filters in it. It takes about 5 minutes to completely clean the air in my small shop.

One thing you should do is direct the airflow such that the air circulates along the walls, around the shop.



With the grate it makes an excellent down draft table, don't get a spec of dust in the air.

[Tom Clark FL]

Here's my dust collector. It's about 20 years old now. Does a great job of keeping the shop air clean. It was made before the ceiling models were on the market. The three drawers are well used also. It sits next to my work bench and catches dust from sanders and routers right where the mess is strongest…

[Adam Shapiro]

Thanks for the feedback. I never thought about building a collector into a base cabinet, but in my basement shop that seems to make a lot more sense.

[Ben Hatcher]

While building it into a base cabinet has advantages, it has a major disadvantage in that it will blow dust that has already fallen to the floor back into the air

[Thomas Bank]

That all depends on where the exhaust is located - which I cannot see in Tom's photo. Tom, does the air go straight through and out the back? Or do you have it vented/ducted elsewhere?

[Tom Clark FL]

Thomas, yes, the air goes straight out the back. The squirrel cage outlet is mounted on the back side. There is no problem with the outlet blowing dust, because with the dust collector there is just not that much dust on the ground to begin with.

When I am working on a project, you can see the dust from the routers and sanders being sucked right into the collector, and the exhaust air looks very clean. The unit really works great. It could have been made lower, but the unit works as an extension to my work bench, and who doesn't need the extra drawers for tools!