will a squirrel cage work in a dust collection system?

[atch]

I have a large squirrel cage fan that was part of the hvac system in a church. I've been thinking it might work for a dust collection system. The motor is NOT inside the fan but drives the shaft by way of pulleys/belt.

I know that these are meant to push air but am thinking that in order to push air it has to pull the same amount of air.

Any thoughts?

 

[Hubmonkey]

The harbor freight one is a squirrel cage fan.

https://www.harborfreight.com/2-hp-industrial-5-micron-dust-collector-97869.html?cid=paid_google|*PLA+-+Top+SKUs+-+All+%28Main%29||97869&utm_source=google&utm_medium=cpc&utm_campaign=*PLA+-+Top+SKUs+-+All+%28Main%29&utm_content=&gclid=CjwKCAiAsOmABhAwEiwAEBR0ZktCKiHqIjRl_5C7asuBNe453em7CjQFwNqVy4pgymxGq624zCS3OBoCo_sQAvD_BwE

I dont have one as I use a Dust Deputy and a Shopvac.

Hub

 

[fartymarty]

I have a large squirrel cage fan that was part of the hvac system in a church. I've been thinking it might work for a dust collection system.

The harbor freight one is a squirrel cage fan.

https://www.harborfreight.com/2-hp-industrial-5-micron-dust-collector-97869.html?cid=paid_google|*PLA+-+Top+SKUs+-+All+%28Main%29||97869&utm_source=google&utm_medium=cpc&utm_campaign=*PLA+-+Top+SKUs+-+All+%28Main%29&utm_content=&gclid=CjwKCAiAsOmABhAwEiwAEBR0ZktCKiHqIjRl_5C7asuBNe453em7CjQFwNqVy4pgymxGq624zCS3OBoCo_sQAvD_BwE

I dont have one as I use a Dust Deputy and a Shopvac.

Hub

I'm fairly certain that the HF uses an impeller not a squirrel cage. Personally I think the squirrel cage type (even a large one) is great for general shop air quality cleaning but not for use on individual machines collecting sawdust and chips, for those I think you are better off with an impeller type air mover. I assume the latter is what you mean by "dust collection system".
No, I have no specialized knowledge in air handling or dust collection, just general knowlege and gut feelings...has worked for me 90% of the time, maybe more.

 

[McFarmer]

I use a clothes dryer fan to pull air through a box fitted with furnace filters and redirects it to the ceiling, works good.
I don’t think it would push much air through a filtration bag.

 

[tapered-pin]

anything will work.. although most dust systems are designed using impellers for a reason..

 

[Renegade1LI]

The HF 2 hp dust collector is an impeller type fan, infact there is an up graded impeller that supposedly makes a big difference over stock. This guy did a good job & lists all the parts.

 

[Mainiac Mat]

terminology is muddying the waters..

Here's a graphic that shows different type of blowers

You can see that the one on the right looks like an exercise wheel for a gerbil and is some times called a squirrel cage. These are most often used in HVAC applications that move air (and only air).

HF DC impellor has an open radial blade design (second from left in illustration). This will handle debris (dust, chips, etc...) entrained in the air stream. This blower is driven by a "squirrel cage induction motor"

I think you "could" get away with using a HVAC style impellor for DC if (and only if) you make a 2-stage unit, where the blower pulls on a cyclone, which in turn separates all but the finest dust and drops it into a container at its bottom. But you need to match the blowers CFM rating to the cyclone design very carefully, or else you'll pass larger debris through the cyclone to the impellor and hear bing, bang, clang as it gets knocked around... likely damaging the impellor fins.

Standard style induction motors are historically referred to as "squirrel cage induction motors", as they too look like a rodent exercise wheel.

 

[bad_idea]

http://billpentz.com/woodworking/cyclone/index.php#index.php

All the info you could ever want on dust collection. Bill Pentz has a wealth of knowledge on his site, to include building a bad *** duct collector for a reasonable cost. He also explains the short coming of exactly what you want to do. Basically HVAC blowers are not built to handle taking a hit from sucking up a piece of wood. The fan blade will get damaged, go out of balance, and come all to pieces.

 

[atch]

Thanx all.

It looks like I'll just buy 3 dust deputies or 3 duststoppers and put one each in conjunction with a shop vac at the radial arm saw, wood drill press, and blast cabinet.

Those are the largest dust makers in my shop; and the drill press is the least of these.

In general I roll the table saw and thickness planer outside when I use them but might do a 4th setup for the table saw. When I grind on metal I just let it fly. The grindings don't go very far so I just sweep them up. Metal drill press, metal band saw, and wood band saw don't make much of a mess.

Shop vacs are dirt cheap at auctions, estate sales, and garage sales. I've actually bought 3 of them in anticipation of doing this. I don't mind using my good shop vac for general use but don't want to tie it up in a fixed permanent situation.

...and then I got to thinking about that big fan up in the loft storage...

.

 

[Spareparts]

Just make sure the motor you use is enclosed, dust don't like open type motors, explosions happen.

 

[shoot summ]

The HF 2 hp dust collector is an impeller type fan, infact there is an up graded impeller that supposedly makes a big difference over stock. This guy did a good job & lists all the parts.

That video clearly shows him removing an impeller, and replacing it with an improved impeller.

And a picture of a squirrel cage fan.

Back to the OP, it is pretty common for folks to build a downdraft sanding table from furnace blowers.

 

[McFarmer]

Thanx all.

It looks like I'll just buy 3 dust deputies or 3 duststoppers and put one each in conjunction with a shop vac at the radial arm saw, wood drill press, and blast cabinet.

Those are the largest dust makers in my shop; and the drill press is the least of these.

In general I roll the table saw and thickness planer outside when I use them but might do a 4th setup for the table saw. When I grind on metal I just let it fly. The grindings don't go very far so I just sweep them up. Metal drill press, metal band saw, and wood band saw don't make much of a mess.

Shop vacs are dirt cheap at auctions, estate sales, and garage sales. I've actually bought 3 of them in anticipation of doing this. I don't mind using my good shop vac for general use but don't want to tie it up in a fixed permanent situation.

...and then I got to thinking about that big fan up in the loft storage...

.

I have a shop vac wired so it comes on with whatever tool it is dedicated to.

Keep those sparks away from a shop vac if there is any possibility of dust present.

 

[atch]

I have a shop vac wired so it comes on with whatever tool it is dedicated to...

Right. On both of my drill presses I have them wired so that the motor and a light come on with the same switch. I'll probably do the same with the shop vacs and the tools. On the radial saw that's a no-brainer. On the wood drill press I'll have to rewire it so the motor, light, and vac all come on together. On the blast cabinet I'll wire it in with the cabinet lights so that the lights and vac come on together.

There are devices on the market that plug into an outlet and have two outlets. You plug the vac into one outlet and the tool into the other. When you turn the tool on the device senses the power draw, waits one second, and then powers the vac. When the tool is turned off it keeps the vac running for 7 seconds and then shuts it off. I've seen at least two brands of these in my searches and they run around $40 - $60 each. I'll probably just do the wiring like I said above though. Alternatively I might just leave the tools wired as they are and turn the vac on and off separately.

 

[Showkey]

Dust vs chip collection is also “muddying” the water.

Chips, actual sawing dust and small chucks impeller wins.

Cage blower for air born dust is preferred........like sanding dust.

 

[acer66]

Dust vs chip collection is also “muddying” the water.

Chips, actual sawing dust and small chucks impeller wins.

Cage blower for air born dust is preferred........like sanding dust.

Yes, I am not so worried about chips that just fall victim to gravity instantly.

I am more worried about the small stuff lingering in the air waiting to set up shop in my lungs.

 

[Renegade1LI]

Just ordered a cyclone XL, Donaldson filter to upgrade my hf dc, 2 wks backorder and no date to get the rikon impeller. These upgrades should really cut down on the fine air borne dust.

 

[like2wheel]

I have an old squirrel cage furnace blower that I've used for various things over the years, and I found that that if I do anything to restrict the intake too much, it just becomes "airbound" & recirulates the air inside without moving any.

So while it is capable of moving a great volume of air, it wouldn't produce a lot of suction.

 

[shoot summ]

I have an old squirrel cage furnace blower that I've used for various things over the years, and I found that that if I do anything to restrict the intake too much, it just becomes "airbound" & recirulates the air inside without moving any.

So while it is capable of moving a great volume of air, it wouldn't produce a lot of suction.

Common misconception on HVAC systems, their function is to blow, the **** part needs to be fairly unrestricted to support the blow part. Granted removing dust wont have an impact on the heat or cool aspect, but those blowers are indeed sensitive to a restriction on the intake side.

 

[LS6 Tommy]

Common misconception on HVAC systems, their function is to blow, the **** part needs to be fairly unrestricted to support the blow part. Granted removing dust wont have an impact on the heat or cool aspect, but those blowers are indeed sensitive to a restriction on the intake side.

X2. HVAC filters are nowhere near as restrictive as dust collection systems require.

Tommy

 

[Bert_]

Common misconception on HVAC systems, their function is to blow, the **** part needs to be fairly unrestricted to support the blow part. Granted removing dust wont have an impact on the heat or cool aspect, but those blowers are indeed sensitive to a restriction on the intake side.

Blocking either the intake or exhaust has about the same effect.

 

[shoot summ]

Blocking either the intake or exhaust has about the same effect.

True, but in this conversation we are talking about using the blower to ****, not blow...

 

[Don1357]

Yes, I am not so worried about chips that just fall victim to gravity instantly.

I am more worried about the small stuff lingering in the air waiting to set up shop in my lungs.

Then you really need to spend a few hours reading the Bill Pentz site. I'll give you the skinny: you want well north of 2HP blower with 5HP being the recommended. You want to use a high efficiency cyclone to pick up the visible dust, you want to bypass filters and vent outside, and you want to spend most of your time designing and implementing the best setup for collection at the source, as in the machine themselves.

I'm the son of a cabinet maker. Over time the fine wood dust will eat your lungs and in my case made me allergic in my old age. Yes, you can be fine all your life and suddenly become allergic to it. You then either give it up or become a lot smarter about it.

Power tip: don't bother to try and setup dust collection for a chop saw, think of it as an outdoor only tool and setup a station outside for it. I rather step outside at -10f to use it than to drop that dust bomb indoors.

 

[McFarmer]

Right. On both of my drill presses I have them wired so that the motor and a light come on with the same switch. I'll probably do the same with the shop vacs and the tools. On the radial saw that's a no-brainer. On the wood drill press I'll have to rewire it so the motor, light, and vac all come on together. On the blast cabinet I'll wire it in with the cabinet lights so that the lights and vac come on together.

There are devices on the market that plug into an outlet and have two outlets. You plug the vac into one outlet and the tool into the other. When you turn the tool on the device senses the power draw, waits one second, and then powers the vac. When the tool is turned off it keeps the vac running for 7 seconds and then shuts it off. I've seen at least two brands of these in my searches and they run around $40 - $60 each. I'll probably just do the wiring like I said above though. Alternatively I might just leave the tools wired as they are and turn the vac on and off separately.

All I’ve done is wire a duplex outlet with a switch between it and a plug. The tools and vac are plugged in to the duplex and their switches are on all the time, just throw the conveniently placed switch and it all comes on.

 

[acer66]

Then you really need to spend a few hours reading the Bill Pentz site. I'll give you the skinny: you want well north of 2HP blower with 5HP being the recommended. You want to use a high efficiency cyclone to pick up the visible dust, you want to bypass filters and vent outside, and you want to spend most of your time designing and implementing the best setup for collection at the source, as in the machine themselves.

I'm the son of a cabinet maker. Over time the fine wood dust will eat your lungs and in my case made me allergic in my old age. Yes, you can be fine all your life and suddenly become allergic to it. You then either give it up or become a lot smarter about it.

Power tip: don't bother to try and setup dust collection for a chop saw, think of it as an outdoor only tool and setup a station outside for it. I rather step outside at -10f to use it than to drop that dust bomb indoors.

I will look into that, stumpy nub had a great imho tutorial about dust collection recently.

Interesting with the miter saw, I have it stationary inside boxed in as much as I could with a dedicated shop vac on an auto switch that has the hose attached to a shut in the lower back bottom of the box and that works pretty good.

 

[NUTTSGT]

I have an old squirrel cage furnace blower that I've used for various things over the years, and I found that that if I do anything to restrict the intake too much, it just becomes "airbound" & recirulates the air inside without moving any.

So while it is capable of moving a great volume of air, it wouldn't produce a lot of suction.

Common misconception on HVAC systems, their function is to blow, the **** part needs to be fairly unrestricted to support the blow part. Granted removing dust wont have an impact on the heat or cool aspect, but those blowers are indeed sensitive to a restriction on the intake side.

This is why I wouldn't use one to attach to equipment but to pull airborne dust out of the air itself. However, using it to push air through a standard furnace filter (like a white pleated $2 filter) or drawing air through the filter. However, it'll go through a ton of filters. Maybe you could blow them out with the air hose outside to get some more life out of them.

The filters on my woodburner blower do a decent job of pulling dust out of the air, sometimes, I wonder where the dust even came from.

 

[Don1357]

I will look into that, stumpy nub had a great imho tutorial about dust collection recently.

Interesting with the miter saw, I have it stationary inside boxed in as much as I could with a dedicated shop vac on an auto switch that has the hose attached to a shut in the lower back bottom of the box and that works pretty good.

Yeah, but the invisible wood dust, the kind that is so light that floats forever and causes permanent lung capacity loss, that escapes into your shop creating long term contamination.

The one good thing about wood dust allergies is that I have a built-in sub micron dust sensor; i may think I'm doing something that is working but my allergies would tell me otherwise.

My 14" band saw came with an inch and a half dust port, which may collect chips but it is absolutely and completely worthless were it comes to picking up invisible dust. I'm refitting the cover plate to take a 4" hose and split the intake to start in the font along the blade path. With the cabinet table saw I'm experimenting with a jet of compressed air pointed at the blade underneath; the purpose is to slow down the fine dust flying at about 100mph (10 inch blade I a direct drive 3400rpm motor). If I can break down that speed of travel the volume going through the 5" intake of the collector ought to be enough to capture it before it can escape.

 

[HelloKittyFanMan]

You can see that the one on the right looks like an exercise wheel for a gerbil and is some times called a squirrel cage.

If it supposedly looks like an exercise wheel for a gerbil, then why is it often called a "squirrel-cage fan" instead of a "gerbil-cage fan"?

I think you "could" get away with using...

"Could" in quotation marks? Why: you don't really think they could; only figuratively?

 

[Jackfre]

I would suggest you use the SC fan you havee to build an ambient air filter box. I have a JDS 750 in my shop. It has a 1x12x24” pleat which feeds into a higher efficiency bag filter. I don’t have particulate instrumentation but this thing has run for over 20 yrs without problems. I think Jet and Delta still have them offered for comparison. I had a 1.5hp Grizzly Cyclone in my last shop and it did very well on my Sawstop, Dewalt 745 planer and 8” Grizzly jointer and all the rest. Mine was not central piped and I used the 4” x 12’ blue flex hose from Rockler which is an excellent piece. Dust Deputies certainly have their place but multiples? Seems you will be doing a doe-see-doe around them all the time. I just upgraded my DC to the Harvey G700 which is a whole different animal. It is mush quieter than my Grizzly or any other cyclone for that matter.

 

[racecougar]

If it supposedly looks like an exercise wheel for a gerbil, then why is it often called a "squirrel-cage fan" instead of a "gerbil-cage fan"?


"Could" in quotation marks? Why: you don't really think they could; only figuratively?

Pulls up a two year old thread to asks these questions as a first post...probably a bot.

As far as the squirrel cage fan goes, yes, they do work great for dust collection.

I built this one entirely out of scraps: bed frame rails, galvanized sheetmetal from an old furnace installation, a direct drive furnace blower fan (squirrel cage) with a 10" x 8" wheel, and some odds and ends. I reuse the used 20"x20"x3.5" Merv 15 filters from my home HVAC unit and pre-filter with cheap 20"x20"x1" Merv 9 filters.

It works exceptionally well in my 30'x60'x12' metal working shop. I've been completely impressed with its ability to prevent the usual grinding / welding haze.