Need blower (fan/motor) to blow dust outside

[Joseph Skoler]

I've read several threaded on exhausting collected dust to the outside and I'd like to set that up in my garage/workshop.

Can someone point me to a nice wall-mountable motor/fan/blow unit?

I have no idea how to do this but I'm thinking cut an 8" hole in the wall, put a short piece of duct and then louvers on the outside (flush with the outside wall).

I'm thinking 8" main duct to 4" branches.

Thank you!

[John K Jordan]

I've read several threaded on exhausting collected dust to the outside and I'd like to set that up in my garage/workshop.
Can someone point me to a nice wall-mountable motor/fan/blow unit?
I have no idea how to do this but I'm thinking cut an 8" hole in the wall, put a short piece of duct and then louvers on the outside (flush with the outside wall).
I'm thinking 8" main duct to 4" branches.

Do you mean use the fan to pull the dust from the machines or first pull the dust with a DC then use a fan to assist moving it outside? Many fans might not have enough suction to pull the dust and chips from the tools then through the branch and main ducts. Some people extract dust from the tools with a cyclone then simply connect the DC exhaust outside. A cyclone can collect most of it to avoid creating a big pile outside.

I know one guy who to put a big fan in the wall behind his lathe to blow everything outside. He used a strong industrial fan, maybe 3' in diameter and cut a big hole in the wall.

JKJ

[Joseph Skoler]

Do you mean use the fan to pull the dust from the machines or first pull the dust with a DC then use a fan to assist moving it outside? Many fans might not have enough suction to pull the dust and chips from the tools then through the branch and main ducts. Some people extract dust from the tools with a cyclone then simply connect the DC exhaust outside. A cyclone can collect most of it to avoid creating a big pile outside.

I know one guy who to put a big fan in the wall behind his lathe to blow everything outside. He used a strong industrial fan, maybe 3' in diameter and cut a big hole in the wall.

JKJ

Thanks very much for the help.

I wasn't clear at all.

I'm thinking (which can be dangerous) of a single blower mounted on a wall and ducted right through the wall to the outside to suck all the dust/chips/etc. from the tools (through duct work) to the outside.

Is that a stupid plan?

[Alex Zeller]

You could buy a dust collector and remove the collection bags and duct it outside. But you'll make a mess. The sawdust will bow against the side of your shop unless you direct it into a pile. You'll then want a tractor with a loader to move the sawdust as it will build up (unless you are on the side of a cliff). I guess you could make it so the sawdust was directed into a wheel barrel so you could just roll it away. Once it gets wet it's even less fun to move. I'm just basing this off of my childhood. We lived near a sawmill and they would blow the stuff into an area that they could then move. Often when bored we would go play in the piles. But even they separated the wood chips from the saw dust before blowing it out of the building as I think the chips would clog the fan.

[John K Jordan]

Thanks very much for the help.
I wasn't clear at all.
I'm thinking (which can be dangerous) of a single blower mounted on a wall and ducted right through the wall to the outside to suck all the dust/chips/etc. from the tools (through duct work) to the outside.
Is that a stupid plan?

I never use the word stupid unless I'm referring to all the dumb things I do repeatedly! I just don't think a fan will work very well. Most fans intended to push air are aren't powerful enough to pull large volumes through small ducts at high enough rates (measured in the number of cubic feet of air per minute) to even pick up much of the fine dust at the source, let alone the chips and shavings. What it does pick up might just end up accumulating in the duct. The fine dust is what you might want to keep out of your lungs. You can pick up the chips and shavings with a broom or a shop vac.

If a simple fan did work effectively people would use them all the time instead of spending the money and effort to install a powerful dust collector. (My cyclone has a 5 hp motor!)

Another problem with pulling things through a fan can be when the stuff hits the blades which are usually not made for that. The beauty of a cyclone is the heavier chips and shavings all go down into a collection bin and only the air with a negligible amount of the absolute finest dust goes through the blades which on mine are on a heavy steel impeller. It's this air which is either filtered or exhausted to the outside.

It's a lot of reading, but if you haven't done so you might look at the stuff written by Bill Pentz: http://billpentz.com/woodworking/cyclone/index.cfm

JKJ

[Joseph Skoler]

You could buy a dust collector and remove the collection bags and duct it outside. But you'll make a mess. The sawdust will bow against the side of your shop unless you direct it into a pile. You'll then want a tractor with a loader to move the sawdust as it will build up (unless you are on the side of a cliff). I guess you could make it so the sawdust was directed into a wheel barrel so you could just roll it away. Once it gets wet it's even less fun to move. I'm just basing this off of my childhood. We lived near a sawmill and they would blow the stuff into an area that they could then move. Often when bored we would go play in the piles. But even they separated the wood chips from the saw dust before blowing it out of the building as I think the chips would clog the fan.

Thank you for the wise perspective. I don't mind getting the tractor once in a while to move a pile, but it sounds like I'd be much better off separating the big stuff before blowing outside.

[Joseph Skoler]

I never use the word stupid unless I'm referring to all the dumb things I do repeatedly! I just don't think a fan will work very well. Most fans intended to push air are aren't powerful enough to pull large volumes through small ducts at high enough rates (measured in the number of cubic feet of air per minute) to even pick up much of the fine dust at the source, let alone the chips and shavings. What it does pick up might just end up accumulating in the duct. The fine dust is what you might want to keep out of your lungs. You can pick up the chips and shavings with a broom or a shop vac.

If a simple fan did work effectively people would use them all the time instead of spending the money and effort to install a powerful dust collector. (My cyclone has a 5 hp motor!)

Another problem with pulling things through a fan can be when the stuff hits the blades which are usually not made for that. The beauty of a cyclone is the heavier chips and shavings all go down into a collection bin and only the air with a negligible amount of the absolute finest dust goes through the blades which on mine are on a heavy steel impeller. It's this air which is either filtered or exhausted to the outside.

It's a lot of reading, but if you haven't done so you might look at the stuff written by Bill Pentz: http://billpentz.com/woodworking/cyclone/index.cfm

JKJ

I really appreciate the help. I wasn't thinking of a regular fan, but rather something made to suck dust -- probably whatever is typically used on 3-5hp DC systems.

But I didn't realize that the chips and shavings could be harmful or detrimental to the fan.

I'm trying to do this on a budget, and thought that not needing to gather/collect all the fine dust air inside would make that easier.

Suggestions?

[Alex Zeller]

What's the budget? I use a Reliant 2hp dust collector that my BIL bought used for $100 then gave to me when he was going to move to China. It came with 4 10' hoses, two aluminum blast gates, some other odds and end duct work, and one of those cheap plastic chip separators that fit over a trash can. It's not the best but it works and I can't see making a different solution for any cheaper (unless you have the parts laying around). If you made it portable so it could go outside I think you could get away with not using the top portion of the collector (as long as the mess didn't bother you, I have no idea how much dust would settle to the bottom vs get blown out the top) to increase the flow. If you can't find anything on Craig's list then try ebay or possibly the harbor freight DC (with one of the 20% off coupons). If your budget is really low and you don't have to worry about keeping your shop warm then you can just mount a couple box fans to push fresh air in from outside and let them push the dusty air out a couple of other openings. It's not going to deal with the sawdust but it will keep the air much cleaner that if you have nothing.

I just did a quick check and there's 5 dust collectors for sale on Craig's list near me. Normally in my area Craig's list is a joke. Prices are either too high or if it's of any value it's gone in an hour. The exact same Reliant I have for $100 and a Powermatic 3hp 1900 with remote control for $600 that look interesting (if I was looking for a replacement). So look around and see what's on the used market. You could be surprised.

[Keith Outten]

Joseph,

I use a 25 year old Grizzly 600 cfm dust collector. I removed the bags when it was new and started using a chip box to collect the chips and dust. When the first plywood chip box I built fell apart from the weather exposure I just blew the chips into a pile for many years and spread the chips over the field behind my house. A few years ago I was able to purchase a 3000 gallon steel tank when a large Ultrasonic Machine was being scrapped and I am still using the tank today. The tank has no top but that hasn't been a problem, the chips and the dust stay in the tank without any problems because its very tall. Many people have asked me how I intend to empty the tank when its full, I had decided to use my tractor when that day comes but I'm sure that before it fills we will have a nor-Easter or a hurricane that will empty the tank in just a few minutes

My system is all 4" thin wall pvc vent and drain pipe so the hole in my shop wall is 4" diameter and the exhaust pipe is only about four feet from the DC to the tank which is behind my shop. If your not using bags and filters you would be surprised at the performance of even a very small dust collector.

When I ran the sign shop at CNU I used the shipping crate that our ShopBot CNC Router came in as a chip box. I installed a couple vents at the end of the box and used baby diapers as filters for the vents. We had to empty the box periodically using a shovel and several 30 gallon trash cans to move the chips to a local dumpster at the University.

[Robert Engel]

Joseph,

I think you'll find it very difficult to buy just a blower of a capacity to match 8" ducts. Penn State Industries used to sell a 3HP blower but only carries a 2HP now. Cincinnati fan is the only company I could find and they are more suited to industrial applications.

I think your only option is to buy a unit with bags and scavenge the motor/blower. You could exhaust into a trailer or large bin but you still have to do something with the shavings.

I would consider a cyclone and exhaust outside. You could also consider locating the blower outside to reduce noise.

[Rod Sheridan]

Thanks very much for the help.

I wasn't clear at all.

I'm thinking (which can be dangerous) of a single blower mounted on a wall and ducted right through the wall to the outside to suck all the dust/chips/etc. from the tools (through duct work) to the outside.

Is that a stupid plan?

Joseph, it's not a stupid plan if you are somewhere where you can actually exhaust chips outside, and you're not heating or cooling the shop. (Cooling would actually be worse due to humidity issues..

I live in Toronto so all 3 of the above are an issue.........Rod.

[Carlos Alvarez]

I recently built a shed to hold a cyclone and 3HP blower. It's been awesome. The cyclone catches everything but the finest dust, which just blows away. It's not even visible in the air, I just know it's there because the inside of the shed is coated with it. I ran 5" ducting around the shop with gates and the appropriate tool drops. Being outside, it helps remove heat from the shop and generally move air in from outside, so the particulate count is always low/ambient. It's also very quiet, so you can still have a conversation while it's running.

Here are photos:

https://imgur.com/a/JmuEs

[Carlos Alvarez]

Oh, and yeah, I didn't find a blower/motor for sale new, but happened upon a great one at a used tool shop. $200 for a Kufo 3HP motor with a 12" impeller. It really moves a lot of air.

[Jim Andrew]

You could add a super dust deputy and have a cyclone system if you already have a blower. Be sure to buy one that has the right size inlet.