# Dust collection questions



## hwebb99 (Nov 27, 2012)

I have a 30x40 foot shop with the back part divided off making my effective work area 30x25. I currently have a Jet canister model dust collector. If I can vent it outside it should be strong enough. I have read that you can't vent a dust collector outside with a vented gas heater. I have a 75,000 BTU vented gas heater so this could be a problem which was the main question in this post. If I can't vent it outside in the winter time I am going to buy a 3hp cyclone unit. I'm pretty well decided on a Oneida with Hepa filters. I plan to vent it outside in the summer time and put the filters back on in the winter. I don't currently have any ducting, but that is about to change. Will 4" be good enough or do I need to go with 6"? I have a table saw, 8" jointer, 12" planer, 24" drum sander, lathe, router table, 12" SMS, 18" bandsaw, and I plan on adding a 6x48 or larger belt sander in the future. I know the Jet will make a pile of chips when vented outside, but it is woods behind the shop so it should be alright.


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## epicfail48 (Mar 27, 2014)

I think this came up the other day in the "shop in the basement post", and I'll admit to ripping the information from it, but the problem with having the collector vent outside is that it creates a negative pressure in the room. Once that happens, air rushes in wherever it can, and if its coming through the vent for a gas fire the inrushing air will suck in the exhaust gasses, leading to a toxic gas buildup. 

As far as the pipe size goes, I'd go with as big as practical for the main line, 6 or 8, then 4 inch for the drops to tools, though the planet and jointer would likely benefit from 6 inch drops


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## woodnthings (Jan 24, 2009)

*Oneida will advise you*

If I recall, when you buy from Oneida they will help design your system...no charge...? 

For a main line, use 6" minimum. Use slow sweep 90's for the 4" junctions to the tools or drops. Use a minimum of flex hose at the tools OR hard pipe them. That's just common knowledge, but as far as specifics, Oneida will advise you regarding length of runs, location of the DC unit, number of drops and the size of the unit. etc.


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## Oneal-Woodworking (Apr 14, 2013)

hwebb99 said:


> I have a 30x40 foot shop with the back part divided off making my effective work area 30x25. I currently have a Jet canister model dust collector. If I can vent it outside it should be strong enough. .


Are you mainly trying to reduce backpressure here?

Because if so - Even with pretty much 'no' backpressure (venting outside)you will not likely notice any difference in suction as compared to a relatively clean and serviceable canister filter. You would need special tools to be able to measure the difference in suction...


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## NickB (Sep 24, 2013)

What kind of heater? My vented gas IR heater intakes it's combustion air from outside, so there's no concern about back pressure. You just don't want to pull the exhaust back in when the heater's trying to vent it out.


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## hwebb99 (Nov 27, 2012)

I have a Hot Dawg heater. The filter on the single stage dust collector clogs quickly. There is a huge performance difference between a clean filter and after 20 minutes of drum sander operation. I know I could put a separator on it, but I would rather vent it outside and be done with it.


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## woodnthings (Jan 24, 2009)

*leave your Jet as is*

Get the Harbor Freight DC unit on sale right now for around $160.00 and just use the blower motor and housing to vent the dust outside. Nothing fancy, but a pretty good way to do it.... and cheap.


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## hwebb99 (Nov 27, 2012)

Would it be counter productive to hook two bowers on the same pipe.


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## woodnthings (Jan 24, 2009)

*there are reasons that won't work*

That idea has come up and the reason it won't work kinda' escapes me ... but the motor will overheat trying to maintain equal RPMs .... or some such thing.

Just get a big arse blower if you need more CFMs. The HF unit should work fine. JMO.


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## hwebb99 (Nov 27, 2012)

The motor will over heat if both blowers have a separate motor? I doubt the HF blower moves any more air than my jet.


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## woodnthings (Jan 24, 2009)

*you missed my statement above*

Leave the Jet as is for a separate application like a shaper, planer, tablesaw, etc. what ever you would want on it's own.

Make the HF blower your main line DC to vent outside.
You don't want 2 motors that are not identical with non-identical blower configurations on the same line fighting each other. It's been tried and don't work if I recall.
However, I found this:
http://www.woodworkingtalk.com/f32/2-dust-collector-motors-same-system-39892/

http://www.woodworkingtalk.com/f12/two-blowers-one-dust-collector-64492/





hwebb99 said:


> The motor will over heat if both blowers have a separate motor? I doubt the HF blower moves any more air than my jet.


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## woodnthings (Jan 24, 2009)

*you missed my statement above*

Leave the Jet as is for a separate application like a shaper, planer, tablesaw, etc. what ever you would want on it's own.

Make the HF blower your main line DC to vent outside.
You don't want 2 motors on the same line fighting each other. 

from Woodweb:
_From contributor D:_ 
The only way this would have any chance of working would be to run the collectors in series (one behind the other). The only problem you have is that the blower on the back side will be trying to draw too much vacuum and will burn out the motor. The only way to keep the back end blower motor from burning up would be to reduce the inlet size, which would reduce the cfm. Your best bet is to get a central system with one motor and one collection point. While you might save a few pennies on electricity, you will spend money on labor to keep emptying bags all the time. We have a large central system outside of our small shop and we spend 15 minutes once a month to clean it out. You can find inexpensive used systems on IRSauctions and Ebay. - See more at: http://www.woodweb.com/knowledge_base/Combining_Dust_Collectors.html#sthash.OJLHP7Mg.dpuf

2 Dust Collector motors on same system?

Two blowers on one dust collector



hwebb99 said:


> The motor will over heat if both blowers have a separate motor? I doubt the HF blower moves any more air than my jet.


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## hwebb99 (Nov 27, 2012)

The biggest problem is I am afraid the dust collector will backdraft my heater. I'm pretty sure I need to put the dust collector back on filters in the winter time. The stove hood in the house vents outside creating a negative pressure in the house, but on a much smaller scale because the house is bigger than the shop and the stove hood moves less air than the dust collector. Anyone want to guess what happens when the stove hood is running at the same time the wood stove doors are open?


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## NickB (Sep 24, 2013)

You could do like you say and install the filter during the winter or just turn the heater off while you're running the DC. Realistically, everything would probably be fine even if they were both running since you're immediately venting any exhaust out anyway, but there is a possibility of un-combusted gas becoming a fire hazard.


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## Oneal-Woodworking (Apr 14, 2013)

hwebb99 said:


> I have a Hot Dawg heater. *The filter on the single stage dust collector clogs quickly. There is a huge performance difference between a clean filter and after 20 minutes of drum sander operation.* I know I could put a separator on it, but I would rather vent it outside and be done with it.


 
Wait a minute here... Ain't those canister filters 'supposed' to be 10 times better than any bag as far as flow rate and level of filtration is concerned and ain't they supposed to only take a few seconds to turn the little flapper inside of them to knock off the fine dust so it can settle to the bottom collection bag and then make the upper 'filter' part like NEW again??? :blink:

(I am being sarcastic here BTW)

This is a picture of the upper 'filter' bag on my Grizz 2HP 'canister' DC taken *while the machine is running*. Machine is 'rated' at 1700CFM and a max of 10" of static pressure when using the standard 1 micron canister. 










I use this DC for 3 machines primarily - One of which is a fairly good size edge sander that gets used multiple times daily and creates a good bit of very fine dust. 

Notice how the bag is not 'tight' and is not blown up 'hard'? 

That is because it is somewhat 'properly sized' for the application and it creates little to no backpressure while in use. ( - bag is actually 'oversized' for my application at it current length...) 

A bag that gets tight and hard during use is china crap and IS causing backpressure. Garbage bags are what come standard on the Grizz and china DC's (that have bags) for the most part. Their micron ratings are not to be trusted either in my opinion...

I had this bag custom made to my specs by AFF. It is rated at 1 micron new and clean. Singed felt (I forget the lbs felt), custom hem and cinch strap at the base for attaching to DC, length and diameter also done custom to my specs. As this bag gets used more it will eventually become 'caked' and actually filter better and at a lower micron rating. (and yes - that WILL create backpressure when it happens)

One generally only needs to tap or smack the side of the bag a few times to knock any buildup loose and send it to the bottom collection bag - Very similar to how the canisters are supposed to work. When the bags are sized correctly you don't have to do this often (and you don't WANT to do this if you do not SEE visible backpressure by simply looking at the bag during use).

The 'rated at' 1 micron canister filter that came with this last DC I bought is not still sitting new in it box because I am stupid... :no:


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## michaelpugh (Dec 31, 2013)

OnealWoodworking said:


> Wait a minute here... Ain't those canister filters 'supposed' to be 10 times better than any bag as far as flow rate and level of filtration is concerned and ain't they supposed to only take a few seconds to turn the little flapper inside of them to knock off the fine dust so it can settle to the bottom collection bag and then make the upper 'filter' part like NEW again??? :blink:
> 
> (I am being sarcastic here BTW)
> 
> ...



I have a couple of questions. I have a 1 1/2hp jet right now with a bag. Looking at a 2hp jet with a canister on Craigslist. Canisters are not better than bags? And my bag is always tight when running, even after I take it off and clean it out. So I'm not getting the suction I should? Can the bags be washed in a washing machine and would that help?


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## woodnthings (Jan 24, 2009)

*several issues here*



michaelpugh said:


> I have a couple of questions. I have a 1 1/2hp jet right now with a bag. Looking at a 2hp jet with a canister on Craigslist. Canisters are not better than bags? And my bag is always tight when running, even after I take it off and clean it out. So I'm not getting the suction I should? Can the bags be washed in a washing machine and would that help?


First,it's the amount of surface area, in sq inches of the filter material that is exposed to the air pressure exiting the bag or cannister filter. If you cut the cloth bag down it's seam and laid it out it might stretch for 6 or 8 ft. If you stretch out the pleats in a cannister filter, it would most likely be double that of a bag, but I donno, didn't do the "test". The theory is the pleated filter has more surface area. 

O'Neals bags are not stock and are taller/longer AND made from a different fabric than a stock bag, so theoretically more efficient and probably so. I don't know about comparing O'Neal's tall bag to a factory cannister... maybe close, I donno?

First hand experience/testimony is always better than theory. The thing no one mentions is that the air sucked into the DC by the blower has to exit through the filter and IF the filter is restrictive, it will not be efficient. So, you want a porous filter that will capture the fine dust but NOT restrict the air flow. It seems that these goals are contradictory to me. Regardless, I vote for the greatest surface area with the best filtration possible.

BTW I have 2 of the Jet 1100 DCs with cannisters and they don't capture ALL the dust, so I use a Jet AFS 1000B air filtration overhead when sanding.

http://www.amazon.com/708620B-AFS-1000B-Filtration-Electrostatic-Pre-Filter/dp/B00004R9LO


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## michaelpugh (Dec 31, 2013)

Yes I added a Laguna 1400 cfm air filtration also and love it but the first filter seems to fill up fast! Haven't had it up that long and I've cleaned it several times already and it looks like I really need to replace it. And I don't work in the shop every day but when I am in there it is on.
Just looked when I bought it I guess it's been up there about a month. Right after I put it up I did a thorough cleaning of the shop with an air hose and that thing running so I'm sure that wasn't a good start for the filter...


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## hwebb99 (Nov 27, 2012)

Factory installed bags suck. There are some good after market bags.


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## Oneal-Woodworking (Apr 14, 2013)

michaelpugh said:


> I have a couple of questions. I have a 1 1/2hp jet right now with a bag. Looking at a 2hp jet with a canister on Craigslist. Canisters are not better than bags? And my bag is always tight when running, even after I take it off and clean it out. So I'm not getting the suction I should? Can the bags be washed in a washing machine and would that help?


The bags I run are not only better at filtering than the canisters that you are talking about but they are also HALF the cost. Only drawback is the space they take up. I 'need' 6 to 8 feet in bag height to have minimal backpressure for a good long while. (mine are 10 feet long currently and a bit 'oversized' for my application at that length)

I 'could' have gone a lot shorter and just increased the diameter accomplishing the same thing. 

If your bag is tight when running - It is not sized properly and not flowing air properly. Washing it is not likely to help that any. 

My bag being discussed here was just a shade over a hundred bucks - The factory canister for my DC is around $220.00. Both are 'rated' at 1 micron new and /or clean but I seriously doubt the Grizzly specs for their china canister are accurate. 

To put a quality AFF bag on your 1 1/2HP Jet would likely run you under $75.00 (guessing between 50 and 75) if you did not go as long as I did and skipped the custom cinch belt and special hems and stuff that I ordered.

I would be willing to bet that if Mr. Webb ditched his factory canister and replaced it with a proper bag he would be able to run his 24" drum sander all day long without ever noticing any drop in performance OR any increase in the fine particles floating around in his shop (as compared to his factory canister).

The misconceptions about bags that are common around here is mostly due to people buying the China DC's with China bags and then they get it stuck in their heads that 'all bags must suck because THEIR bags suck'. Instead of 'trying' a better quality bag they get sucked into buying a very expensive canister filter at 2 to 3 times the cost and then wonder why it gets clogged up so quickly when dealing with fine dust.


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## michaelpugh (Dec 31, 2013)

My ceilings are only 8'. The roof is about 14' but the area I'm using as my shop has a ceiling built in. The rest of the building had a suspended ceiling that I tore out and had foam insulation sprayed. I wish I would've taken the ceiling down in my shop at the same time but it wasn't as easy (being built in) and I was in a hurry. I hit that [email protected] ceiling all the time...be hard to have an 8' bag with only 8' ceilings


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## michaelpugh (Dec 31, 2013)

Where would I research a custom bag? Do you have yours made locally?
I found a jet 2hp dc with the vortex and canister that has barely been used on cl for $550. Seriously considering it. I think I could sell mine for $200 so I'd really only be out $350. I'd get 1/2hp more, the "vortex" and the canister...


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## Oneal-Woodworking (Apr 14, 2013)

michaelpugh said:


> My ceilings are only 8'. The roof is about 14' but the area I'm using as my shop has a ceiling built in. The rest of the building had a suspended ceiling that I tore out and had foam insulation sprayed. I wish I would've taken the ceiling down in my shop at the same time but it wasn't as easy (being built in) and I was in a hurry. I hit that [email protected] ceiling all the time...be hard to have an 8' bag with only 8' ceilings


 
You could fatten the diameter and achieve the same effect without going as high up...










I stole that pic from the AFF website just to illustrate this idea to you...


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## woodnthings (Jan 24, 2009)

*the bags*

http://www.americanfabricfilter.com/


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## michaelpugh (Dec 31, 2013)

That's awesome. I'll check it out.


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## Oneal-Woodworking (Apr 14, 2013)

michaelpugh said:


> Where would I research a custom bag? Do you have yours made locally?
> I found a jet 2hp dc with the vortex and canister that has barely been used on cl for $550. Seriously considering it. I think I could sell mine for $200 so I'd really only be out $350. I'd get 1/2hp more, the "vortex" and the canister...


You can get a 2HP Grizzly canister DC new for just under 500 delivered if you sign up for the email bombardment and get the 25 bucks off shipping coupon...

http://www.grizzly.com/products/2HP...h-Aluminum-Impeller-Polar-Bear-Series/G0548ZP

You need to be looking at CFM and static pressure moreso than HP in my opinion... 

This is the bottom collection bag that I had AFF make for me recently:









This is heavy duty, non-breathable fabric. The older Taiwan DC's with cloth upper and lower bags generally use the same exact material for all the bags. (meaning the lower 'collection bag' also works as a breather bag until it starts to get full) 

If I ever let this bag get full as a tick of fine dust and then 'need' to drag its heavy ass 25' over concrete to get it to the dumpster to empty it because I can't find the dolly - I can. And I bet I can do that over and over without any problems at all for a very long time. I just can't see a plastic bag holding up to that. :no:


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## michaelpugh (Dec 31, 2013)

Grizzly G1030Z2P - 3 HP Dust Collector with Aluminum Impeller - Polar Bear Series

Here's the way to go. 3hp for $419. Back to cloth bags but I could upgrade them from aff and would be rocking.


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## ChiknNutz (Apr 22, 2011)

michaelpugh said:


> Grizzly G1030Z2P - 3 HP Dust Collector with Aluminum Impeller - Polar Bear Series
> 
> Here's the way to go. 3hp for $419. Back to cloth bags but I could upgrade them from aff and would be rocking.


I am considering this one along with the G0548ZP which is a single cansister but is the same price. I don't get why these are priced the same, so to me it seems the G0548ZP is somehow better but why? It has less HP, less CFM and half the storage capacity. What am I missing here? Oh and how does this compare to the HF one that I see so many go with?


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## ryan50hrl (Jun 30, 2012)

Since upgrading the 1030 3 hp unit would cost roughly 400 bucks, and you can buy the G0562 unit with the canisters already installed for less than 300 more, I'd chose between the G0562 or the 2hp G0548. I'd skip the G1030 if it were me.


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## ryan50hrl (Jun 30, 2012)

Oh, and the canisters are much more expensive than the filter bags, so that's the reason the G1030 can be priced the same. It is not as good.


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## Oneal-Woodworking (Apr 14, 2013)

michaelpugh said:


> Grizzly G1030Z2P - 3 HP Dust Collector with Aluminum Impeller - Polar Bear Series
> 
> Here's the way to go. 3hp for $419. Back to cloth bags but I could upgrade them from aff and would be rocking.


I use a much older (but pretty much the same Taiwan machine) 3HP DC just like that near and primarily 'for' a planer. The one I am using has something like 10 or more micron china upper bags that are around 6' tall each and they blow up *very firmly* when the machine is in use. (that is not really what you want for efficiency - The harder the filtered air is to push OUT - The less suction you will have at the other end) Due to the upper bags (10 + micron china bags in my case) being so restrictive to airflow - I actually get *better suction* from my G0548ZP (2 HP DC that is MUCH less restrictive to airflow). 

Before I bought my G0548ZP specifically for my particular machine cluster that I wanted to use it for - I would roll the 3HP DC over in that spot to do the DC work on those particular machines. Part of the reason I bought my G0548ZP was to avoid the pain in the ass of having to move that 3HP DC every time I wanted to use those particular machines and actually have decent DC very close to the source... 

Perhaps they have made changes to the baffle design inside the ductwork or something here recently to help the bags fill more 'evenly' (and I seriously doubt it) but with the one I use (identical machine ductwork to the one in the Grizzly picture for that model) the bag on the right side usually gets emptied 5 times before the bag on the left gets close to needing it... I save no time by having twice the 'collection area' because the bag on the right always fills first and fills much more quickly than the one on the left and will need dumping before continuing on. If you do not empty the right side bag once it is full - The chips will continue to collect inside that side of the DC until they start filling the upper bag which is 'supposed' to be your 'filter bag' and not a 'collection' bag. You lose filter area when that happens and further chug down the machines ability for suction... 

The one in the Grizzly ad above has the (claimed to be) 2.5 micron bags and they are almost half the size (same diameter but much shorter in length / height) of the bags on what I am using (3 HP model). 

Grizzly wants me to believe that this machine can filter to a much finer level and do it in about half the breathable area for the fabric (upper bag filter) than what I have currently... :| 





That simply ain't happening with those bags and that machine... :no: 





Keep in mind here that the china bags running on the 3 HP version I am using are not only much larger in actual filter surface area but they are also rated at a much higher (more porous) micron rating which means that they should be able to flow more air than any lower micron rating bag of the same size / area.



You would want to upgrade for sure if doing any sort of work involving fine dust as the bags that come standard on that Grizzly are not anywhere close to being the right size for that sort of job at that micron rating. Even when sucking up 'chips' as compared to fine dust I can't for the life of me see how they pull that off with the filter bags being so small.










No such thing as a 'free lunch' in my mind (but Grizzly claims there is).


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