Dust collector piping.

[Ryan Grondin]

Originally I was going to run a 6 inch trunk run down the middle of my ceiling and branch off. But, my shop isn't huge.. and I'm starting to think the 6 inch would be over kill since I'd be branching off with 4 inch anyway... The furthest tool from my dust collector is about 25 ft away at the end of the run. But I can disable that part of my run with a blast gate and the next tool, my table saw is at about.. 20 ft from collector intake to tablesaw port... 3hp motor.dual dust bags. Just wondering ig I should even bother with the 6 inch since it's really not that far... and I'm not hooking up 20 tools to it... I can manage it with blast gates when using a specific side of the shop. Probably going to start installing it in the next few weeks. Building a small enclosure on the back side of my garage, plenty of space back there to store saw dust and shavings.. etc.  It'll keep noise down and fine dust inside the shop, bought a couple air cleaners to hang from the ceiling to help with the finer stuff.

[..Kev]

First thing to do is to be sure that your equipment is where it's going to stay for a long time.  Either you'll use PVC (or similar inexpensive) piping that will be a PITA to move or you'll be using expensive (think Nordfab) stuff wich will be expensive to move.

Once that's in place, then I'd suggest a design service to get the most out of the machine you choose.  Yes, it costs a few bucks but, will save the headaches in the end.  In my case, I used Clearview cyclone and Nordfab ducting and the design service was about 250 bucks.

Your other option is a bunch of research, reading, and math to get decent results out of your machine.

By the way, my longest run is only about 30'.  I have a 5HP collector and a 7" main trunk. 

[Eric.]

I gotta disagree with my buddy Kev.

If you're getting a real system like he has...a 5HP cyclone and Nordfab duct...yeah, pay for the service.

If you're like me (or you) with a puny little 2 or 3HP tinker toy, slap the 4" up however you please, trying your best to minimize length of run and sharp turns, seal the joints as best you can, and take what you get...which will be mediocre collection.

Hiring a company and throwing money at a weak system is just a waste...I'd save that money and put it towards a real system that you'll buy down the road.

I have a similar system to yours, 2HP with 4" duct...it picks up the bulk of the mess pretty good but it doesn't do much for the fine dust.  Dollars to donuts you end up with the same results regardless of how your ductwork is designed.

[gee-dub]

Its a math thing for me.  CFM is based on air speed of a given mass.  A 4" pipe has to move air pretty fast to get to the speed/volume required to keep fine dust airborne.  Dust collectors are not vacuum cleaners and use different fan curves to do their job.

I have found 6" ASTM-2729 PVC pipe pretty easy to modify when compared to metallic pipe.  Buy a couple of extra 10' sticks and some extra wyes and 45's and you should be good for quite a bit of change.

45's make gentle 90's and 6x6x4 wyes can hold gates at the transition to 4" if you choose to reduce.  One advantage of 6" pipe on 3HP and smaller systems is that it is less likely you'll have to upgrade the majority of the system if things aren't working well.

These are older pics but, show the general transition from 6" to 4" at some of my machines.

[Ryan Grondin]

Yeah That is exactly what I had in mind with the 6 to 4 transition... Looks good! Now to find some 6 inch pipe... Probably have to hit a plumbing supply... the bix box stores dont carry it near me.

I'm planning on using some silicone caulk instead of pvc glue so I can still take it apart in the future if I need to make changes. 

[Andy Wright]

On 8/16/2016 at 9:15 PM, Ryan Grondin said:

Yeah That is exactly what I had in mind with the 6 to 4 transition... Looks good! Now to find some 6 inch pipe... Probably have to hit a plumbing supply... the bix box stores dont carry it near me.

I'm planning on using some silicone caulk instead of pvc glue so I can still take it apart in the future if I need to make changes. 

I agree with Eric that you can just improvise with a PVC system rather than spending thousands on a customs designed duct system .

 

I have a 6" PVC main line that goes down to 4" at the drops and it works pretty well.   I had to order the 6" sewer and drain fittings from a plumbing supply house

 

[Ronn W]

Here is what I used to design my system.  Remember that if you close off all of the tools not in use you really don't have a main duct and branches.  You are only using the most direct line from the tool in use to the DC and all of you piping can be the same size.  If on the other hand you want to run more than one tool at a time or not mess with gates at every tool your duct sizes will vary.  Good luck.

Air_Handling_Design_Guide.pdf

[Ryan Grondin]

Thanks guys.. Appreciate all the feedback.

[Tom Cancelleri]

Duct design isn't difficult for a small shop. If you go with a more powerful unit, you can get away with some of the inefficiencies of using HVAC ducting and not having perfect design. If you do however take proper design, and airflow into consideration you'll be just fine.

Sent from my Nexus 6P using Tapatalk

[ben_r_]

You should always go with the largest diameter pipe you can (sized to the blowers inlet size) for as long a distance as you can with gradual step downs to the tool port. Use 45 degree wyes for branch off, never T connections and if you need 90 degree elbows use two 45 degree elbows to give the 90 degree turn a longer sweep.