Delta 50-760 Outdoor Exhaust - First Iteration

[Dave Sepucha]

My "shop" is in my garage which is also used for other things like parking a car and storage. I have a Delta 50-760 with the standard bags, and have been unhappy with the amount of fine dust that still coated everything in the garage, not to mention how my lungs felt after several hours working on projects. I was planning on making some updates including a nice cannister filter and a ceiling mounted air cleaner. One day I made an offhand comment to my wife that I'd really prefer to just vent outside and she said "go for it."

So I embarked on a journey to MacGyver my DC. My plan was to build a pre-separator and mount the DC on the wall. As I got into it, I really like several things about this approach...
- Should be no need for an "air cleaner" in the shop
- No significant purchases to be made (air cleaner, filters, etc.)
- DC mounted on the wall to reclaim valuable floor space
- Less fine dust (hopefully) all over the garage

Here's where things are so far...

Gratuitous baffle shot (before fittings were sealed with foil tape):
218055

DC Wall mount (Had to relocate the lumber rack):
218056

Bracket detail:
218057

Separator:
218058

Some details: The exhaust is 6 inch pipe with a bellmouth (http://www.spiralmfg.com/hoodsf.htm) to start it off. Other than the bellmouth, there's nothing in the MDF sandwich on the left side of the DC body. I figured I'd keep the DC body so I wouldn't have to make my own to house the impeller.

The brackets are made from three pieces of 3/4 ply laminated together and routed to fit the contour of the DC body.

The inlet uses the standard 5 inch port on the DC and necks down to 4" to the separator.

The separator itself is a 40-ish gallon fiber barrel and for the ports I used Rockler's kit (http://www.rockler.com/product.cfm?page=25225&filter=34367&pn=34367) and cut off one of the elbows. I had planned to cope a piece of PVC pipe and mount into the barrel horizontally (think cyclone entry) but I didn't realize how thin the walls of these barrels are. I decided I wouldn't be able mount the pipe securely, so I just used both of the Rockler components. Obviously the bend of the inlet hose is way too severe. I noticed quite a bit of leakage on the Rockler pieces so I used foil tape to seal up everything underneath the baffle cover.


General thoughts:
Without the separator this setup roars. Although I have no means of measuring, it definitely "feels" like it sucks more than the standard setup with the cloth bag. The separator and that darn super-flexible hose make a noticeable impact on the performance.

This setup currently works very well for me, but I don't have any large tools. Before I get my cabinet saw, I want to increase the size of the pipe on the inlet to 6" and I'll toss the separator for a Super Dust Deputy. That 4" pipe isn't doing me any favors.

The separator works very well with the actual separation, but it does appear to have a negative impact on airflow at the tool. I've taken steps to prevent any leaks in the separator itself, but there is still a noticeable impact.

Living in CO I was a bit worried about the cold, but I'm more worried about dust, so losing the barely warm air in my garage wasn't a big concern for me. I'm actually pleased with the time I've spent working since the changes. If my DC were running non-stop, then maybe the cold would be an issue, but I'm fine in a long sleeve shirt and maybe a vest.

All in all I'm really thrilled with the setup and I see areas for improvement. I'm really happy that my only expenses were the ducting and the barrel. Any money I could save in this area is a big help since there are many other things I'd rather spend the cash on.

Next steps:
- Clean up the wall around the exhaust
- Put in a vent on the other side of the garage for some makeup air
- Replace the separator with a super dust deputy
- Mod the DC to run 6 inch pipe from the DD to the inlet

Thanks to SMC for all the great posts with other projects, links to vendors, and references to good sites. They were a huge help.

Thanks for reading.

[Ben Hatcher]

Very interesting. I have the same model and was considering venting mine outside as well. The guy who did an energy audit of my house said that the house had a 2000 cfm air infiltration which was actually ideal for the size of the house. I haven't done it yet because I'm worried that my make up air will be drawn from the furnace flue. Do you notice a draft coming from your exterior doors while the dc is on?

[Prashun Patel]

I've been thinking to retro my Delta 50-760 to vent outside too. I have a cannister filter, but there's no beating external venting (heat loss notwithstanding).

The thing is, you mentioned fine dust covering everything previously. The 50-760 comes with a 1 micron bag. While not perfect, it should certainly not allow visible dust to escape. If that's happening and you're really feeling it in your nose and lungs, then I suspect you either have a leak, the piping's not sufficient, or something else. Most likely, you might benefit from some above table collection on stuff like the bandsaw or tablesaw...

Venting outside alone might not solve those probs.

[Dan Friedrichs]

Venting outside alone might not solve those probs.

He's probably moving more air without the filter restriction, though, so that should help.

I'd be concerned that the dust deputy will actually add more resistance than the separator does. You might try leaving it, but getting rid of the flex hose.

[Dave Sepucha]

You're certainly right, the dust that settles around the garage isn't necessarily due to the filter or the DC. This is just the first step in trying to improve overall dust collection. I agree that I also need to improve above the table collection and collection at-the-tool in general. (Using my router away from the router table comes to mind as a particularly messy operation.) Improving at-the-tool collection is also a driver for wanting to move to 6" pipe. I had already purchased the smaller pipe and decided to go ahead and install it for now. One thing about the stock filter bag was that I ~really~ didn't like the amount of dust that would come off it when I would shake or smack it to release some of the dust buildup on the inside.

Ben, I work in my garage which is not a particularly airtight space to begin with. (When it's nice I just work with the garage door open) The door to my house is well sealed, and I haven't noticed increased draft coming from there. I also don't have a furnace or water heater in my garage so pulling air in from the flue isn't really a concern for me. That said, I do plan to install 2 exterior vents to provide makeup air on either end of the wall that faces the DC-mounted wall.

[Dave Sepucha]

I'm definitely curious about the performance of the larger DD, it would be a disappointment if it adds more resistance than the separator does. That flex hose does have to go. I'm in the process of building new stations for the router table and miter saw which will not need that hose. A shorter length of stiffer flex hose will be used to connect to the TS. Even an elbow out of the separator inlet would likely be an improvement over what's there now. That particular hose is the one sold by Rockler as part of their Dust Right system and is like a slinky. It's crazy to see the number of twists and turns that it makes for even a simple connection.

[Prashun Patel]

I use 4" flex hose that's slinkier than slinky. But it's not that long - less than 10feet. I've never - with this DC - had a problem with dust settling everywhere. The only time that happens is when I route indoors. For my money, the best dc on a router is a shopvac connected to the base (plunge) or fence (table) (with a preseparator or a good outdoor filter spanking b4). I'm not trying to be difficult. I'd just hate you to go thru a lot of expense b4 yr options are explored - some of em more efficient.

I'm still perplexed as to why yr filter is emitting so much dust when smacked.

[Dave Sepucha]

I'm still perplexed as to why yr filter is emitting so much dust when smacked.

Not anymore. ;-)

[Matt Day]

I'm still perplexed as to why yr filter is emitting so much dust when smacked.

Mine does the same thing.

[alex grams]

Hmm, this is almost identical to what I am considering on my setup. Though I am very interested in the super dust deputy performance.

Do you notice any problems with makeup air since you are pulling from the garage and not returning to the garage?

[Dave Sepucha]

In my limited use so far I have not noticed any problems, though I do plan on installing vents on the opposite wall to provide makeup air. (For those times when I work with the garage door closed)

[glenn bradley]

The 50-760 comes with a 1 micron bag. While not perfect, it should certainly not allow visible dust to escape.

You may be surprised at how visible 1 micron is. Various types of smoke and ash, cooking flour dust and so forth have particles well under 1 micron. they have particles well over 1 micron too but, that belittles my point :D.

[Ben Hatcher]

You may be surprised at how visible 1 micron is. Various types of smoke and ash, cooking flour dust and so forth have particles well under 1 micron. they have particles well over 1 micron too but, that belittles my point :D.

A thick enough layer of any size particle is visible.

[Don Jeansonne]

I can't seem to improve the layer of shop dust all over. I am considering the outside venting. I just added a separator and am waiting to see what improvements.
I do also see the dust emitting when hitting the bag but maybe when it is really heavily coated. I know the Thien baffle is catching most of the dust. My situation is I do a lot of sanding especially a drum sander.
Outside venting is not a problem for me in Louisiana - venting can be a good thing.
I know that I can improve tool collection as band saw, jointer, and miter have none.

[Michael W. Clark]

I have a friend of mine that did something similar except he just used an exhaust fan to blow all the chips outside. Connected all the ducting straight to the fan inlet. He cleans it up outside every once in a while when company comes over.:)

If you are getting the large dust deputy, why not put the Delta back together and sell it? Then with the money from selling the Delta unit, put that toward a 3HP exhaust fan with a 6" inlet. Lay the fan on its side and connect it directly to the top of the Dust Deputy. Spin the fan so it discharges through the wall. You would have more HP, more CFM, more SP, better collection for that future table saw. Even if you used a 1.5HP blower instead of the 3HP unit, it seems like you would have more CFM available, because of the housing losses in the Delta unit. A cyclone without an after filter is basically what you are making. Just my $.02.

Mike