# Ideas for my old furnace blower motor...air filter or other?



## SteveEl

Soon we're gonna replace our 1950ish gas furnace, and I'd be grateful for shop suggestions how best to make use of the relatively new 110v 1/3hp motor that drives the belt-driven squirrel cage. The cage itself is a monster.... bigger than a case of beer. 

Anybody? I have the space for an air filter cabinet that size, but still.... how else would you use a 1/3 hp motor in your shop?


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## Gary Beasley

Air cleaner is a perfect recycle purpose for the fan. Later up several grades of filters for optimum performance with the coarser grades outside. Good luck.


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## JamesGlenn

I used one to build a downdraft/work cart. It's fairly big, but works great. Also acts as an air filter. Has drawers, cleanouts, outlets, clamps, etc.. Also acts as an outfeed table for the tablesaw.

Sort of the center of operations for me, and it works great.


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## mikeintexas

Wow, what cool ideas for reuse of fan motors. Some pics would be nice to see. Sorry I don't have anything helpful to add...I just enjoy seeing what ideas folks come up with for this kind of thing.


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## JamesGlenn

mikeintexas said:


> Wow, what cool ideas for reuse of fan motors. Some pics would be nice to see. Sorry I don't have anything helpful to add...I just enjoy seeing what ideas folks come up with for this kind of thing.


I have a couple in 'My Photos" and could always get more if you email me.


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## dmh

If you don't have one definitely build an air filter cabinet. I did the same thing with a smaller fan and it's one of the best things I've ever done for my shop (and me). Before anything gets cut, turned, sanded or sprayed, the filter gets turned on.

I'm not a stickler for remembering and sticking to safety things but my filter is something that I always remember.

To test it, spray paint something black in your shop with it on and look at your filter a few minutes later. You will be surprised at what's floating around in the air (and also what your breathing).


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## SteveEl

An air filter cabinet is a definite. Just not sure I want to run the ancient squirrel cage. I'll post a pic after the furnace replacement, and see what ya'll think then.


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## Nick Ferry

SteveEl said:


> An air filter cabinet is a definite. Just not sure I want to run the ancient squirrel cage. I'll post a pic after the furnace replacement, and see what ya'll think then.


 i look forward to seeing some pictures - i as well have an old furnace fan and want to do the same thing - mine is about 2 feet cubed - i dunno if i will be able to figure out the wiring though


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## dmh

mikeintexas said:


> Wow, what cool ideas for reuse of fan motors. Some pics would be nice to see. Sorry I don't have anything helpful to add...I just enjoy seeing what ideas folks come up with for this kind of thing.


Nothing fancy but it works.


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## mikeintexas

Thanks for posting those, DMH. In that last pic, is that a flourescent bulb sticking into the box? I may have to make something like this; though I don't have a spare squirrel cage motor.

I am setting up a small shop in my garage. This weekend I was cutting circles out of plywood and MDF with my router. The air in the garage filled with dust...it was hazy in there. Yes; the door was closed. It's cold outside! I've also cut a few boards with the circular saw...dust wasnt' too bad with that.

Making something is how I'll have to go as budget is tight. I know squirrel cage motors can be had fairly cheaply if you know where to look.


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## dmh

mikeintexas said:


> Thanks for posting those, DMH. In that last pic, is that a flourescent bulb sticking into the box?


:laughing: No it's just a spare bulb I stuck up in the rafters (one of these days I'll finish the ceiling in my shop:blink.

I know what your talking about. Routing MDF (the cloud) is what got me to originally get off my butt and make it.

Make or buy one. You will be surprised. No more hacking on monday's after playing in the shop all weekend. I get very little of the fine dust settling on things all over the shop and it doesn't take a shovel to clean out my nose anymore.:laughing:


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## mikeintexas

Thanks, DMH. Everything in the garage is covered in dust...will have to get after it with the air hose...with the door open, of course. I'll check CL for some squirrel cage blowers. I wonder if there is an "ideal length" for the box? Minimum length? I'm sure it all depends on the CFM rating of the motor, no? Don't have much room in my garage due to it being semi-finished (sheetrocked all around) but I could fit a small one somewhere, I'm sure.


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## rrbrown

JamesGlenn said:


> I used one to build a downdraft/work cart. It's fairly big, but works great. Also acts as an air filter. Has drawers, cleanouts, outlets, clamps, etc.. Also acts as an outfeed table for the tablesaw.
> 
> Sort of the center of operations for me, and it works great.


Pictures would be nice. I've seen one of those in one of the woodworking magazines and even thought of building one just never got around to it and then changed my mine.


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## mikeintexas

Any ideas how to calculate how many CFMs the cage fan should have? I Googled "How many cfms for cabinet filter" and got links for calculating the fan for a bathroom. LOL! Like this: http://www.ehow.com/how_4793146_calculate-cfm-bathroom-fan.html

Is it the same concept? Cubic feet of the workshop divided by...well...divided by what? I'm overanalyzing this thing, aren't I? :huh:

The other side of my brain says "Just find one, build a box and stick a filter in front of it!" I'm thinking Other Brain is right for a change...


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## dbhost

Air filter springs to mind, as does building a sharpening station. Shop notes had a great design 2 or 3 issues ago... But really, motor AND squirrel cage fan? Air filter...


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## dmh

mikeintexas said:


> Any ideas how to calculate how many CFMs the cage fan should have? I Googled "How many cfms for cabinet filter" and got links for calculating the fan for a bathroom. LOL! Like this: http://www.ehow.com/how_4793146_calculate-cfm-bathroom-fan.html
> 
> Is it the same concept? Cubic feet of the workshop divided by...well...divided by what? I'm overanalyzing this thing, aren't I? :huh:
> 
> The other side of my brain says "Just find one, build a box and stick a filter in front of it!" I'm thinking Other Brain is right for a change...


Live on the edge! Just build one.:laughing:

I'm sure there's a calculation out there to figure the air exchange rate for the size of fan but I would think that unless you have a 2000+ square foot shop that just about any residential furnace or A/C fan would work fine. Me personally, if I was to build another one I would look for a 110v fan that's not belt driven. But that's up to you. The fan I have came out of an old single wide trailer. Its a small 110v unit and works fine for my 600sq ft dust making area.

When making your box all you really need to focus on is making sure sure you have enough room on the sides of the fan for good air flow. Once you figure out your approximate box size go to your local HD or whatever and pick out a common filter size to fit it and start building.

All your basically needing to do is pull air through a filter.:thumbsup:


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## mikeintexas

I'm thinking a filter size of 14x25. That's a very common size and they are pretty cheap (if you buy the cheap ones.) That would be more than enough for my garage. I'm definitely going with a direct-drive fan. No belts/pulleys for me. That's one more thing to break and maintain. There are a few 400CFM squirrel cage blowers on Amazon for roughly $115, shipped, but that's much more than I wanted to spend on this little project. Need to scour CL...didn't see much yesterday.


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## Nick Ferry

just a quick thought - i dunno if someone already said but, if poss make it same as your furnace so you wont need two different sizes - i was thinking of doing that for mine


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## BWSmith

This is a 1/3 HP Blower motor,picked up w/squirrel cage on side of rd.......maybe 10 years ago.

It has a Scot Murray knife wheel on it.Look at the end of the rubber drum,see the angled slots?The way they're oriented(turning direction)changes the amt of hardness on drum.

The motor's been floating around from spot to spot.....used occasionally for soft sanding certain pcs.....but mainly use this for sharpening Tig electrodes.The belts slip on and off,loosley....until motor gets turned on,then drum expands to grip belt.

The stand has also been just pushed from one spot to another for about the same amt of time.Found a whole pile of these old(14") Cragars on the side of road with free sign on them.Been making swivel stools for ******* buddy's,ect,ect,.

The two mated for a sand job on some funky furniture pcs.I think they're both happy?BW


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## woodtick greg

I made a dust filter for my basement shop out of a 110v belt driven squirrel cage from my old house furnace. if it will circulate the air in my whole house it definately circulates the air in my shop many times over. if i forget to turn it on when I'm working and then turn it on, it only takes a few minutes to clear the air. made it so it takes the same filters as the new house furnace, I buy them in bulk at the big box store and there always on hand. I don't have dust collection in my shop yet so this thing is great! you guys might check with a heating and cooling co. as they always have them on hand from replaceing furnaces in peoples homes, most co. just scrap em. I've seen them on the curb on garbage day. hey everyone just build one, they are cheap, fun to build, use little power, and work great!


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