You can literally drive yourself crazy trying to get this to be perfect. There are quite a few folks that have done exactly what you want and are quite happy with the results. The thing is their expectations of the system may be quite different than yours. I think maybe if you check the Pentz site and do your reading there you may well find the answers to your questions that are based on test results (versus opinions). On the other hand there are many who believe his info is the extreme end of things and of little use to a hobbyist. I am not one of them, he has about the most comprehensive set of data available and it's well worth the time to peruse, consider starting in the FAQ section to get a feel for things. That said, I'll offer my opinion on what you want to do. The vertical distance will be of very little impact on your airflow, so can be disregarded. You DC is small to be right on the edge, but I think you could use 6" ductwork and get acceptable performance. I suggest you run one pipe down through the floor and then split it off to make things easier to manage. You may well want to change things around in the future..different tool, additional tool, etc.

 

Thank You for the advice on the Pentz site. After pouring through that and some of the info on Phil Thein's, I'm on the edge of install. I ended up with a HF 2hp, only thing I have used was the motor, impeller and intake ring. I reworked the ring to 6" intake, the exhaust on these is 4x6 but they necked it down to 5" so I built a 4x6 duct. I also found the exhaust flange is bent up and around creating a "U" shape the exhaust air hits, so I addressed that, I used a lot of bondo in reworking the ring for smooth flow, so I bondo-ed that lip for a smooth exit. I upgraded to the larger WEN Impeller, and painted the interior with graphite paint (very slick and smooth). When the unit came, I measured its CFM, yup was about half of advertised at 800 or so which was expected. After my mods, including the CFM eating thein baffle, I now measure 1150 CFM! That's is before my filter gets added on and ducting, but still a vast improvement. I'll be doing 6" mains, the thein will be up on the ceiling so I eliminated the duct length to go from it sitting on the floor to the ceiling.

I'll share once all done.

But I wanted to thank you and other folks for sending me in the right directions for research. I've driven my poor wife nuts with going crazy over the research of airflow . But now feel I have a much firmer grasp on the science of this stuff, by no means a seasoned expert but have learned a lot in the process.

Thank You

 

This one?

 

Yes I beleive so. And if not this one, was thinking similar... But am just at the beginning of conceptualizing and learning so that could change if I get "sold" on other info or unit....

 

I've found that a hand brush with a dust pan works consistently.

 

I have a different brand of 2 hp collector, and 5" ductwork hits the sweet spot for that size machine. 4", too small, and 6" too big. I have my whole shop, 16 x 22 ducted in 5", and it works great. 26 gauge steel duct, long radius 90's

 

I use 4” and 3” on the drops..

 

how about a wynn filter on that unit...1 micron vs 2.5

 

I think I definitely should consider one. I am going to do a dust extractor that should be quiet and therefore in use most of the time we are in the shop not just when the big equipment is running. If we have a dust extractor this has a 1 micron filter on it, would it be necessary to have on the dust collector too? Not challenging your thought, a question out of the ignorance of dust collection knowledge I'm trying to gain...

 

The Wynn cartridge goes where the cloth bag is. at the top of the collector. Those cloth bags don't capture the smaller particles so instead of a dust collector, you have a dust sieve and all the small stuff that is really bad for your lungs gets mixed with all the return air.

 

Well that makes that decision a bit easier! Thank you!

 

the planer or jointer which would sit on our work bench when in use or the Table saw that would be set to the one side of the work bench when in use

Do these machines that you're sitting on the work bench have 4" or larger ports? A lot of benchtop machines only have 2.5" ports. Machines with small ports are better served with a shop vac or better yet upgraded to 4"(where possible). DC's don't work well when reduced to small ports.

 

Planer is 4", Jointer is 2.5, and chop saw is rather small. shop vac would be fine for the occasional jointer use.

On our Miter saw is a 1.5" . I really don't want to use a shop vac on that one as I just want it set up ready to roll as that is so often a "casual use" saw, as in may be used when not working on a big project so it would be nice to not have to get the shop vac out. Would it be more effective on the mitre saw to not neck it so far down, but just place the 4" drop line right over the small dust outlet? That way what the saw "flings" would just be in the airstream? Rather than try to neck that poor thing down to where it won't work?

I hope that question made sense.

 

Just make sure you can get to it to clean it out. I just bought a DC and have had to clean it out twice already. Climbing up to the attic to clean chips and shop towels out of the impeller would not make me happy.

Also by putting it in the attic you might inadvertently transfer noise to other areas of the shop or to connecting buildings. Dust collectors are loud so I understand your wanting it in the attic. I put mine in a closet and it's still loud and blows the door open. I may put the thing outside. Good thing is they suck dust like nobodies business!

 

Just make sure you can get to it to clean it out. I just bought a DC and have had to clean it out twice already. Climbing up to the attic to clean chips and shop towels out of the impeller would not make me happy.

Also by putting it in the attic you might inadvertently transfer noise to other areas of the shop or to connecting buildings. Dust collectors are loud so I understand your wanting it in the attic. I put mine in a closet and it's still loud and blows the door open. I may put the thing outside. Good thing is they suck dust like nobodies business!

Twice weekly? Are you filling it up that much?

 

+++ on 6” ducts. No question 4“ will degrade performance, but could still work depending in the layout and length of runs.

 

So run as large as possible as far as possible before dropping down in size for the tool? Would it be best to keep the duct full sized to just shy of the tool? Or right to the tool and drop its size right at the tool hookup?

 

Just one thought/general comment. Sawdust is highly flammable and makes a great fire starter. To that end, and it goes without saying, always keep in mind that you may need to install some type of static discharge for any duct runs. You never know where the static may come from, even a missed nail in a pallet. And especially if you use plastic ducting. Metal ducting cannot be isolated either. All need to be grounded.
My garage floor seems to be a great dust collector. My woodworking project of the day involves a broom, dustpan, and collection box or can. Maybe the garden before plowing?

 

So you would be in the camp that for a hobbyist, just deal with the sawdust at point of creation? Maybe just use the shop vac to keep it from blowing all over, but to not add a fire risk with a ducted DC system? Not challenging, I'm learning, and my ears are wide open to everyone's input. Is the fire risk "real" as in not an unheard of event? Or is it more theoretical?

 

Dust collector fires are started by embers from things like pinched saw blades burning the wood, dull router bits, picked up metal sparking in the ducts or hitting the impeller. There has never been a fire or explosion proven to have started from static electricity in a home shop system. The DC and ducts are too small to build up enough of a charge to create a hot enough spark to ignite dust. We also do not produce enough dust to reach the concentration levels needed to be a problem. The sparks are a nuisance and might distract you while cutting and you jerk your hand back into the path of a blade. Static can discharge back through a computer controlling a CNC and damage it. The explosion fear is a widespread myth.

Pete

 

BUT! Why take the chance. Ground it!

 

The only sensible thing (IMO) about avoiding dust bin fires is that the floor sweeps are a bad idea with a DC because you are likely to sweep a nail or screw into it, then the nail hits your metal fan and sparks into your bag of saw dust. Now if you regularly saw thru nails that may be another story. With the cost of saw blades I tend to avoid that.

I power sweep with a SV which has a plastic fan. I have a couple of brooms too. And once in a while I open the doors and windows and have at it with a leaf blower.

My PVC DC pipes have never shocked me. Others may have different experiences.

 

PVC ducts will build static, and can discharge to ground through metal blast gates, flex duct.

Fires in ducts is a myth busted long ago.

I did have smoke coming from my table saw cabinet once I believe caused by a hard piece of knot from a hot blade.

You don't hear of many wood shops burning down, do you?

 

Call me paranoid, but I have a 4” pvc duct system that I ran a bare copper wire inside and wrapped around the outside. My shop is in the basement of my home and I don’t think that it is worth the chance of burning down my house over $20 worth of copper wire.

 

OK, you‘re paranoid. 🤣🤣

 

😂 LOL

 

I have a somewhat similar sized shop but lucky to have a separate room for the dust collector. When our house was being framed I had the framers put in some joists and plywood in the unfinished area under the house and turned it into a shop. I had never had dust collection before and went a bit crazy on the design at first. I started with 6" metal ductwork and the price ended up being crazy ($3,000 for 5" Nordfab). I ended up with 4" PVC sewer and drain pipe hung from the ceiling with straps. I did splurge a bit and got a cyclone filter unit and was glad I did. Hardly anything gets past that and into the bag below the filter. The person at the local woodworking supply shop advised not to go with 6" pipe as it won't have the optimal velocity you would get with a 4" pipe with a Jet DC-1200VX 2HP. I only used 6" pipe between the Dust Collector and the Cyclone unit. I also highly recommend going with a remote control. It was a pain in the butt to get all the right sized fittings for all the machines, blast gates, flex hoses, etc.. What helped was to cut off a small section of the PVC pipe and take it to the store along with the other things you need to attach to. The other highly recommended dust collection accessory I recommend is the Shop Nation 3D printed adapter for miter saws. I had some 3D printed in color just for fun. It really improves dust collection.
See the attached floor plan and pictures. Send me a message if you have any questions. Cheers, Lee

 

I’ll look up the shop nation stuff, one of my boys has a 3d printer. Thank you for all the input- I’m trying to soak it all in! really appreciate it

 

I would also suggest designing a cyclone separator in your system…then your need to clean out the cloth filter goes way down. You don’t need to worry about sweeping chunks or gravel into the system because those pieces will never hit the fan. But there is a pressure loss with a cyclone separator. So the design suggestion is that you run 5” duct into the cyclone and 4” duct out. Oneida makes such a cyclone separator.

Given the speed of air in the duct, the effect of gravity is negligible, so don’t worry about that from a design perspective. The velocity must be sufficient to keep the dust suspended, otherwise your pipes will load up with dust somewhere.

More important than gravity is the diameter of the duct. Too big a duct and the velocity will drop too much. Too small a duct, and the frictional losses will cause pressure drop. So I ditto the suggestion above to do 5” duct. But…

5” plastic duct is really hard to find. And 5” fittings. This is what I found out. So a single length of 5” from blower to separator and 4” thereafter is how I would design.

 

I would also suggest designing a cyclone separator in your system…then your need to clean out the cloth filter goes way down. You don’t need to worry about sweeping chunks or gravel into the system because those pieces will never hit the fan. But there is a pressure loss with a cyclone separator. So the design suggestion is that you run 5” duct into the cyclone and 4” duct out. Oneida makes such a cyclone separator.

Given the speed of air in the duct, the effect of gravity is negligible, so don’t worry about that from a design perspective. The velocity must be sufficient to keep the dust suspended, otherwise your pipes will load up with dust somewhere.

More important than gravity is the diameter of the duct. Too big a duct and the velocity will drop too much. Too small a duct, and the frictional losses will cause pressure drop. So I ditto the suggestion above to do 5” duct. But…

5” plastic duct is really hard to find. And 5” fittings. This is what I found out. So a single length of 5” from blower to separator and 4” thereafter is how I would design.

But 5" steel duct and fittings is readily available, and eliminates the annoying static build up.

 

There is an insane amount to learn. There's at least one book out there about it and lots of information online. My approach is to not be obssessive, but just use a lot of power. I have a 1.5hp cyclone I use for my table saw and my band saw. It's annoying because it gets clogged and it's not easy to tell if is (I have to pull the container out and stick my arm up there) and underpowered but it's better than nothing. I use 4" PVC and haver one or two bends in both lines. I have a 3HP 3-phase 2 bag machine that sounds like an airplane I use for my jointer/planer. That DC and the planer are both industrial beasts.

I a built pine table and 2 benches recently and I filled up the bottom bags 3 or 4 times. That's enormous chip volume. If you do any real planing, think about that. No other common shop machine comes even close to producing so much waste. Fussing with the metal clamp bans is no fun.

When I had a lunchbox planer I would use a Lee Valley trash can cyclone lid and a 1hp dust collector. Almost all the chips ended up in the trash can and it was a piece of cake to empty. At the time I was using a shop vac with a foot switch for my table saw and it worked better than you might expect. Now I have overhead DC on the table saw too and I like that.

Here's a thread about my clever blast gate design. They work flawlessly. https://www.lumberjocks.com/threads/overhead-blast-gates.41990/

 

I really like the design of your gates!