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I'm in the early stages of designing a dust collection system for my home shop. My existing system, a dustpan and broom, is vastly inefficient for my setup, which includes a tablesaw, router table, planer, and various small power tools. Long-term, my goal is to plumb my shop to run ductwork to each of my three main tools from a centralized dust collector - I haven't yet mapped out a design for this, but the tool area of my shop is around 20x15, and I'd need to run to all three tools.

When doing my initial research to get a feel for the costs, I've run into a variety of recommendations for materials to use. Some sites insist that PVC pipe is the best "affordable" option, while others strongly warn against using it due to static buildup. Most of the other options I read about are more expensive, often by a significant amount, so I want to know if it's possible to save money by using PVC, or if the risks outweigh the convenience.

Is PVC a safe material to use in a dust collection system, and are there any specific precautions I need to take in order to use it?

  • Hi AHiggins, welcome to our site. It seem like you're asking for a comparison of all possible piping/ductwork materials out there with respect to their sawdust-handling abilities. This is a very broad question. Maybe you can provide some more details about your specific setup (e.g., how many feet of piping you need, how high you'll be lifting the dust), and ask for a recommendations for this type of shop? – drs May 17 '15 at 18:23
  • Thanks for the feedback! I started asking a more specific question, but broadened it in an attempt to make it more widely useful; I should have known better, and will edit this to bring it up to scratch. – AHiggins May 17 '15 at 19:03
  • Dangit rob, I was in the middle of making that edit :p – Daniel B. May 18 '15 at 3:53
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PVC is commonly used in dust collection systems. Typically for longer runs you should use 6" or larger pipe, regardless of the material. If you're using PVC, the larger, less expensive pipe is commonly available as sewer drain pipe.

As of May 2015, there have been no known fires caused by a static discharge in a PVC pipe from a dust collection system.

Because PVC is an insulator, you are more likely to get a number of small static discharges than a single large static discharge.

Even if you want to ground your PVC anyway, simply running a ground wire through the PVC will not be very effective because--as I mentioned before--PVC is an insulator and charge does not travel across it very easily. Only the surfaces of the pipe in direct contact with the wire will be grounded, and any points not in direct contact will not be grounded. Grounding the outside is pointless because no charge will travel from the inside to the outside, or vice-versa. If you suspend the wire directly through the middle of the pipe, you still won't collect and ground much charge because air is also an excellent insulator. If you want to effectively ground the system, you need to entirely cover the inside of the pipe with a conductive coating, then ground the inside of the pipe to the components on either end of the pipe (dust collector and tool), as if you were running metal pipe. Suffice it to say, it's a lot less work to just trust physics and use PVC pipe as-is without any extra unnecessary precautions.

If you're still concerned, I'd suggest reading the following articles, which cover the topic in much more depth:

Lastly, keep in mind that if you are running a central dust collection system, you aren't going to get enough airflow or air velocity if you cheap out on the dust collector itself. Once you've planned out your pipe, crunch the numbers with Bill Pentz's static pressure calculator (Excel spreadsheet) to find the CFM and static pressure requirements, and use those as the minimum specs when shopping for a dust collector.

  • Rob, thanks for the excellent and well-researched answer. I'd apologize for the delay in commenting, but that's what you get for linking to those articles. I think I need another day just to read them! – AHiggins May 18 '15 at 17:04
  • @AHiggins no worries; glad to help! – rob May 18 '15 at 21:40
  • Static charge will absolutely flow across the surface of the pipe. Consider the case where you get shocked from touching a statically charged pipe. If the charge did not flow across the surface, as you claim, then you could get another shock by touching another slightly distant part of the same pipe. But that's not what happens, when you get shocked you can't do it again until the pipe's charge builds up again. Thus, grounding a small screw drilled through the pipe will reduce static build up significantly. – Samuel May 17 '16 at 18:07
  • I've watched huge sparks fly between plastic tubing used for pneumatic conveying and nearby metal objects. Do not use plastic tubing unless it is continuously grounded. Strap or spiral-wrap a ground wire along the full length of the tubing. If it's close to the tube but not touching it there will likely be small sparks. If it gets too far away there will likely be large sparks. If you touch an ungrounded part of the tubing you may get a huge static discharge. – Mark Jul 15 '16 at 21:37
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I don't know about PVC tubing with regards to static build-up, but an important thing to consider that you may not have thought about is that having a small bend radius when you're going around corners etc. can actually choke up your system and cause you to lose a lot of suction power, as it gives more resistance. If you use standard PVC tubing and standard elbows, and you have to go around lots of bends then this could be an issue.

I'm also unsure of the abrasive-resistant properties of PVC, though depending on how much you'll be using it, this may not be a problem.

As for what I've seen used, I've only ever seen solid metal tubing, or flexible polyurethane tubing - the stuff with the wire wound through it in a spiral, like a spring:

enter image description here

This stuff is not drastically expensive and is easy to route and install as it's flexible.

I have no experience of PVC tubing as dust extraction, but I've always worked in a professional environment with purpose-made extraction. There is however a discussion here which suggests that PVC is a very bad idea. Remember that wood dust is highly flammable and at the right concentration in the air can even be explosive. Personally I wouldn't take any chances with static discharge.

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    That's why PVC tubing should be grounded. – Maxime Morin May 18 '15 at 1:27
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    Turns out that the need to ground pvc is mostly a myth, if you understand the physics. There have been some good articles in woodworking magazines about that in recent years. However, running a "ground" wire won't do any harm, outside of adding a bit to the cost, so if you don't trust the numbers feel free to apply that bit of insurance, – keshlam May 18 '15 at 2:48
  • @keshlam While that might be true it would be worthy of having a reference for the myth. – Matt May 18 '15 at 3:31
  • @WhatEvil as the question is specifically about the safety concerns associated with using PVC pipe, I'd suggest focusing more on answering that particular question. Also, you can buy PVC wyes, 45s, and long sweep 90s, so there is no more an angle issue with PVC than there is with metal pipe. Although I think the recommendation of flex tubing over PVC is off-topic, if you want to include that discussion you should also point out the performance tradeoff of flex hose vs. solid pipe. – rob May 18 '15 at 4:22
  • @WhatEvil, thank you for the suggestion! Part of my original, too-broad question was asking about alternative options to PVC, so the information is useful to me even if not directly on-topic. Your link did provide some extra information about the PVC tubing, and for that I thank you! – AHiggins May 18 '15 at 17:06
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If you work in a professional wood shop (Oregon) use of PVC piping for combustible/wood dust collection is a no no and can get you a fine (Due to the static build up regardless of the use of a ground.) It's more well known that using PVC for compressed air lines is a no no and a osha violation but same thing for ventilation / dust collection.

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Our operator was injured from a static discharge of a PVC pipe entering his hand and exiting his elbow, so it is not a myth. This was in a dust collection application.

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