Dust Collector - exterior exhaust and wet scrubber?

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Forum topic by WoodFiend posted 10-22-2018 03:23 AM 1633 views 0 times favorited 13 replies Add to Favorites Watch
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4 posts in 663 days

10-22-2018 03:23 AM

Topic tags/keywords: dust collector wet scrubber dc dust

Hi All,

I’ve read a lot of the posts on dust collectors, there seem to be some generally accepted rules of the road but also a lot of room for interpretation and personalized approaches. One size definitely doesn’t fit most.

I am getting back into wood working and am in the process of setting up my shop. I have a Delta unisaw and 6” jointer and a 10” miter saw along with powered hand tools. I’m looking at how best to work handle dust. Currently I use a shopvac connected to a simple 5 gallon bucket lid venturi chip collector.

My shop is 25×40 and about 100’ from my home. My shop and home are set back in the woods well away from neighbors and I’m not worried about impacting them. My house is about 100’ from the shop.

That said, What I am considering is a 2HP HF dust collector with a cyclone and exterior discharge. Due to the location of the shop, I’m not worried about impacting neighbors, but I am concerned about a dust plume heading toward the house. To address this, I thought I might do is try to build a simple wet scrubber. I would duct the exhaust with the fines into an open 55 gal drum, and use a shower at the rim. The bottom third of the drum would act as a sump and I would use an electric sump pump to recirculate the water.

In tandem with this, I am thinking about mounting an axial fan at just below the rafter level to blow air out a vehicle access door to try and carry the suspended dust out of the building and get some air changes..

I would also wear some sort of respirator or PAPR during heavy dust generation.

I might be out of left field and I appreciate any thoughts. I’m not afraid to spend money on a good dust collector, but I think that if I can exhaust external and then use some sort of post discharge control that I can get something reasonable without spending thousands.

Thanks for reading and look forward to any feedback.

-- WoodFiend

13 replies so far

View ChuckC's profile


844 posts in 3746 days

#1 posted 10-22-2018 03:34 AM

The best thing I did was vent my HF DC to the outside. I use it with a Thien baffle and a standard dryer vent kit to the outside.

I also have a Powermatic air cleaner in the shop as well.

I can’t speak to the web scrubber idea but it seems like a little overkill.

View Brazz04's profile


43 posts in 1677 days

#2 posted 10-22-2018 04:01 AM

I too think the scrubber is probably overkill for what you need, Buy the harbor freight kit and use a thein baffle or a super dust deputy with it. Both will do a good enough separation job that you won’t need to worry about plumes of dust. I run mine through a wynn filter, but venting out side would help even more with the separation efficiency.

Here’s my setup with the harbor freight parts and a thien baffle.

And this is another of my setups using the HF blower on a SDD XL (but the SDD is better if you don’t plan on going to a bigger blower motor)

Both will do what you need and have no plumes, I run them with my drum sander and the fines are nearly all in the dust bin.

View Heyoka's profile


58 posts in 663 days

#3 posted 10-22-2018 04:05 AM

Just remember that if you vent to the ourside you will have a negative air pressure inside and will continually be drawing ourside air into your shop. Something to think about if needing HVAC in your shop….

-- Heyoka

View BattleRidge's profile


150 posts in 1027 days

#4 posted 10-22-2018 03:57 PM

I agree with the concerns about venting outside and a lot of complications can set in if you are heating your shop, particularly in the area of heat loss and in the aspect of a properly functioning heater if you use natural gas, propane or similar heaters.

I started with a shop vac / Dust Deputy combination and recently upgraded to a 2hp Grizzly G0548Z with 1 micron canister filter that I picked up from Facebook Marketplace for $200. The shop vac / DD still works nicely with the sander, router table, scroll saw and handheld equipment, but for the bigger machines I use the Grizzly and it does a good job of filtering. I have a 30’ x 40’ x 10’h workshop but only have one section dedicated toward woodworking. In the summertime I typically have a garage door open on each end of the shop with a 24” barn fan for cooling that additionally clears the air out. In the wintertime I keep things closed and the shop heated while working.

I live in the middle of our 103 acre hardwood tree farm so the ultimate disposition of sawdust isn’t a major concern, but for my overall dust collection, the relatively simple system I have works quite well. I did recently pick up a Super Dust Deputy Cyclone at a scratch-and-dent sale at Woodcraft for $20 and would like to install it at some point which should improve things even more – though it works quite well as is.

-- ~Art~

View Fred Hargis's profile

Fred Hargis

6328 posts in 3304 days

#5 posted 10-22-2018 04:10 PM

Skip the wet scrubber, you are way overthinking this. The discharged dust should be fairly minimal, and should also only be the finest particles…in the 100’ to the house they will be dispersed sufficiently that it won’t be a problem. But try this: build your setup without the wet scrubber and try it for a few months. Then make a judgement about adding it to the mix.

-- Our village hasn't lost it's idiot, he was elected to congress.

View WoodFiend's profile


4 posts in 663 days

#6 posted 10-22-2018 06:24 PM

Thanks for all the feedback, I am going to move forward with the HF 2HP collector and I am going to try the Thien baffle with an exterior vent and pick up an air cleaner. I have a wood stove for the shop and I will keep the vehicle door cracked for make up air.

I appreciate you all sharing what you have, I read Bill Pentz’s website and it had me thinking I needed to go high order. Thanks for bringing me back to earth :)

-- WoodFiend

View mathguy1981's profile


94 posts in 715 days

#7 posted 10-22-2018 06:28 PM

Make sure when you buy your HF machine, you don’t be an idiot like me and pay full price. They’re are always 10-20% coupons online, just google to find some. I did this a few months ago, and I got the Wynn 224 filter for it from Wynn Environmental. Cost more than the DC! But it’s an amazing filter. Something to consider if you’re going 2 stage with a Thien Tophat.

-- Two thumbs and counting

View fivecodys's profile


1642 posts in 2447 days

#8 posted 10-22-2018 07:54 PM

Thanks for all the feedback, I am going to move forward with the HF 2HP collector and I am going to try the Thien baffle with an exterior vent and pick up an air cleaner. I have a wood stove for the shop and I will keep the vehicle door cracked for make up air.

I appreciate you all sharing what you have, I read Bill Pentz s website and it had me thinking I needed to go high order. Thanks for bringing me back to earth :)

- WoodFiend

Here is what I did.

I haven’t seen any evidence of dust building up on the bushes right by the vent so I think the Super Dust Deputy is doing its job.

-- A bad day woodworking is still better than a good day working.

View Bill_Steele's profile


715 posts in 2543 days

#9 posted 10-23-2018 03:37 PM

I’m sure you could vent to the outside with no issues—especially given the location of your shop. I’m curious why you would do this? Is it to avoid having to check and empty the dust bin or does this somehow improve the efficiency?

Are you moving the entire dust collector outside or just redirecting the exhaust ducting? Are you planning to remove the filter? I think the cyclone should help reduce the discharge to just the very fine dust. Given the distance from the house I think you should be ok and it will be unnecessary to wet the dust to knock it down. I guess alot depends on how much breeze you get and the direction—to avoid dust blowing back into the shop in the summer time.

I suppose if you do not have a fine filter on your dust collector then venting outside will probably reduce the airborne dust in your shop. Moving the entire collector outside would reduce shop noise and free up space.

View MJClark's profile


37 posts in 695 days

#10 posted 10-23-2018 03:39 PM

At the moment, it is a shop vac but I am looking at getting a cyclonic 5 gallon bucket attachment that will be a dry system. It will all be internal because my shop is in my garage and my HOA would flip out if they knew that something other than the storage of vehicles was in there.

View bondogaposis's profile


5807 posts in 3162 days

#11 posted 10-23-2018 04:49 PM

Venting outside is a great idea unless you are heating your shop, in which case you will be drawing cold air into the shop while expelling heated air to the outside.

-- Bondo Gaposis

View MrRon's profile


5926 posts in 4054 days

#12 posted 10-23-2018 05:01 PM

Unless you are doing a commercial amount of work, I see no need for a scrubber. My shop is the same size as yours and located around the same distance from my house, actually much closer. I have never had any problem with dust and the house.

View clin's profile


1114 posts in 1807 days

#13 posted 10-24-2018 02:37 AM

Fine dust is bad for you, but even if the wind were blowing it directly towards your house, I think it would spread out so much before moving 100’ it wouldn’t matter at all.

I’d be more concerned with making sure the intake vent to your shop for the make-up air doesn’t draw the dust back in. And I agree with the others that a water system is solving a problem you don’t have.

No question you will be pumping heated/cooled air outside when running the dust collector. And you would completely exchange the equivalent of all the air in the shop in about 15 minutes. But unless you are running the DC constantly, this probably isn’t an issue. Even exchanging all the air in the shop, is not the same thing as cooling the shop down to outside temperature. The air itself doesn’t hold that much heat, the heat’s in the walls, floor, and stuff in the shop.

It will cool the shop, but I’d guess most of the time you won’t even notice. Of course it depends on the project, but I think most of us doing hobby work, make some cuts, scratch our heads for 30 minutes, make a few more, and so on. So the machines and DC are not on all that much. Obviously a production shop is a completely different situation.

-- Clin

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