Best practice for DC hose to point of use?

[Tony Gomez]

lets start by saying I have never had a DC beyond a shop vac. So trying do finally do this right.

While I build up my CFlux 2 which arrived yesterday, I'm trying to figure out what is the best way to connect the mobile DC to individual tools. My use will be me wheeling the DC to the table saw, 8" jointer, or 13" planer and using 10' of flex hose. All my tools have 4" ports. The planer (DW735) technically is a 2 1/2 port with a 4" adapter and the planer has a built in blower to assist chip/dust removal.

The CFlux 2 has a 6" port and an adapter for 2x 4" ports so I'm thinking my options are
1) DC to tool with 4" flex hose
2) DC to tool with 6" flex hose, use 4" adapter on tool (perhaps use Rocker Dust Right kit for easy tool disconnects)
3) DC to tool with 5" flex hose using 6 to 5" and 5 to 4" adapters (still use Rocker disconnects)
4) DC to tool with 5" flex hose, modify table saw and jointer to accept 5" hose. I could manage 6" on the planer, but the G0715P can't do 6 unless I cut into the metal.


My "reading online but no actual experience" knowledge tells me that
#1 will be easy but flow will be crippled to achieve 1000 CFM, but maybe it is still ok for good chip removal? (I wear P100 hepa masks with garage door wide open when I work, so the fine dust collection might be fine)
#2 The 4" port will reduce the velocity too low in the 6" hose for good chip movment up to the DC.
#3 Should addressthe velocity issue, has the ease of the disconnect, and less 4" in the system means better CFM then all 4" system
#4 Probably the best for saw and planer wrt velocity and CFM. Would need an adapter for the planer. Can't use quick disconnects.

Toolmetrix did some measurements with the CFlux 1 and measured CFM of 10' of straightened flex hose, and they got ~650 CFM which according to the Laguna chart, is ~ 6.5" static pressure. The CFlux 2 chart shows that at ~6.5" static pressure, the CFM would be ~ 900 CFM.

Oneida has all the hose and adapters to make any of this happen (just not sure right now when to select crimped or not on the adapters).

There is my brain dump. Sage words from the experienced?

[Josh Kocher]

Here are some rough numbers for you.

10' of:
4" flex ~ 15" static pressure
5" flex ~ 5"
6" flex ~ 2"

Tapered dust hood:
4" ~ 3.2"
5" ~ 1.1"
6" ~ .5"

The manufacturer published performance curve for your collector shows you'll get about 1000 cfm at 5" static pressure.

http://lagunacleanair.com/product/cflux2/

[James Gunning]

Tony,

The best practice is to run a 6" duct from your Laguna to the port on the machine. Have the port on the machine sized at 6", or use multiple ports to approximate the 6" area. For example, two 4" ports is slightly less than a single 6" port in area. I understand the reluctance to cut into a tool to install a 6" port. I worked around it myself. Always try to get as close to 6" duct as possible since that size will flow to most air within the capability of your DC. If you have to use something smaller, just keep in mind you're always looking to maximize the airflow. Run the 6" as close as possible to the machine and adapt down in size there.

The following photos show how I handled the change to 6" ports on several of my machines.

Powermatic-jointer.jpgHood-for-Dewalt 734-12.5-inch-planer.jpg18-inch-Jet-bandsaw.jpg18-inch-Jet-bandsaw-2.jpgHookup-on-table-saw.jpgInlet-for-drill-press-and-sander-DC-hose.jpgFloor-Sweep.jpg

First is a Powermatic 54A jointer. HVAC fitting epoxied into MDF. Next is a register boot adapted for a Dewalt 734 planer. It mounts the same way the factory adapter did, except the port sticks straight up when mounted. Then, two shots of a Jet 18" bandsaw using an MDF manifold connecting the 4" factory port with an added 2" duct to clean out under the table and add more airflow. The fifth from the left shows a Ryobi BT3000 hooked up to the 6" flex duct. The maroon "thing" is a manifold connecting the 2.5" blade shroud on the top to a 4" blast gate opening into the saw body on the bottom. Next is a inlet I made to clamp to my drill press and Rigid spindle sander allowing use of the 6" DC line to help catch the chips. Finally, a floor sweep made of MDF scraps. All the fittings are 6" metal HVAC and MDF epoxied together. The flex hose uses a crimped HVAC fitting that slides into the port fitting on all the machines.

[Larry Frank]

Before you go to far, just try the 4"flex hose. If you get the 900 cfm, then you are fine. I would buy a digital manometer and use it with the Laguna performance curve to estimate flow.

Everyone seems to think that the best way is to enlarge the machine ports. It may be, but not always needed. I am using the 4" ports with my Oneida Super Dust Gorilla -5 hp and get adequate flow according to Pentz.

As a note, I measured my dust collector performance with a hot wire anemometer and digital manometer.

[Josh Kocher]

Definitely try the 4" hookups, but I surely wouldn't run 4" flex hose all the way... run 5 or 6 and reduce at the machine.

Larry's 5 hp Baldor motor and larger impeller allows him to overcome more resistance and still get adequate airflow. Oneida's chart shows that system still pulls 1200cfm at 9" static resistance... in fact it doesn't chart a cfm lower than that... at 5" it does 1600cfm

The 2hp Laguna is a different capability altogether... at 9" 200cfm... 5" 1000cfm...

[Tom Bodet]

Then, two shots of a Jet 18" bandsaw using an MDF manifold connecting the 4" factory port with an added 2" duct to clean out under the table and add more airflow.

James, that setup is exactly what I've been pondering but couldn't visualize. Thanks for posting the pics.

[John Lanciani]

Here are some rough numbers for you.

10' of:
4" flex ~ 15" static pressure
5" flex ~ 5"
6" flex ~ 2"

At what volume? The problem with generic numbers like this is that they are incomplete at best, or outright wrong at worst. You need volume and static pressure to have anything meaningful. According to your "rough numbers" a dust collector that deadheads at less than 15" SP would not be able to move any air through 10' of 4" flex and we all know that that is just not true.

Unfortunately the only real way of knowing if a given installation will produce satisfactory results is to assemble and test it. A dust collector is an integrated system, and as such it is virtually impossible for the average user to calculate the performance of the system using only incomplete data from various components of the system.

I've offered this before and I'll offer it again here; I have all of the equipment needed to test a dust collector and it is available for loan. Anyone interested can look here for details; http://www.sawmillcreek.org/showthre...ffer&highlight=

[Bill Adamsen]

Jame's photos are great. On a combination machine the dust hookups are all 120mm (about 5") so I use a quick disconnect from Spiral (my solid pipe is all Spiral) to connect a single flex hose to whichever machine is being used. They disconnect and reconnect easily and that setup has worked for me. I actually used the same connectors when upgrading the dust collection on other machines such as the Unisaw shown. The connectors are not perfectly efficient, but they are I believe reasonable (they work).

[Steve Cowart]

I think you should absolutely test with just 4" first. Especially if you are not running any ducting. I have the same planer and run 4" all the way to it with the last 10 feet being flex and it works great. You have slightly more (Better) DC system than I do. No matter what you do with ducting, unless you make major modifications to the planer you won't see any real difference. If it works fine with the 4", its MUCH easier to live with. I have 4" running to all my tools and am very happy with the results. Larger ducting is really critical when you are running more than 1 machine at a time, but for 1 at a time 4" can be fine in most cases.

As has been pointed out, it is VERY difficult to calculate all the variables involved and get meaningful results. At some point in the future you will probably want to use some hard ducting and make things more permanent, then you can rethink your approach based on what improvements you need.

Don't get caught up in "Analysis Paralysis". Try the 4" and THEN upgrade if needed.

By the way, I use the 4" "Anti-Static" hose from Rockler for my planer, and it is far better than standard hose.

[Josh Kocher]

At what volume? The problem with generic numbers like this is that they are incomplete at best, or outright wrong at worst. You need volume and static pressure to have anything meaningful. According to your "rough numbers" a dust collector that deadheads at less than 15" SP would not be able to move any air through 10' of 4" flex and we all know that that is just not true.

Unfortunately the only real way of knowing if a given installation will produce satisfactory results is to assemble and test it. A dust collector is an integrated system, and as such it is virtually impossible for the average user to calculate the performance of the system using only incomplete data from various components of the system.

I've offered this before and I'll offer it again here; I have all of the equipment needed to test a dust collector and it is available for loan. Anyone interested can look here for details; http://www.sawmillcreek.org/showthre...ffer&highlight=

The numbers are from the static loss calculator on Bill Pentz's website and while not exact certainly provide a good approximation to work with when choosing ducting components for your system.

Absolutely build it blind, cross your fingers, hope for the best and test it to get the real numbers... but why not use the available information to build it with a chance the real numbers will meet your expectation.

You just bought a $1500 cyclone, why worry about a couple extra bucks for the larger duct? I'm not sure why anyone would encourage 4" duct with the amount of information out there that contradicts it's capabilities.

[John Lanciani]

The numbers are from the static loss calculator on Bill Pentz's website and while not exact certainly provide a good approximation to work with when choosing ducting components for your system.

Absolutely build it blind, cross your fingers, hope for the best and test it to get the real numbers... but why not use the available information to build it with a chance the real numbers will meet your expectation.

You just bought a $1500 cyclone, why worry about a couple extra bucks for the larger duct? I'm not sure why anyone would encourage 4" duct with the amount of information out there that contradicts it's capabilities.

The problem with that is that the "data" on Pentz's site ranges from decent to imaginary to pure garbage. Bill had an axe to grind, he is not an industrial hygienist nor an engineer in the field he preaches. Bill can tell you his opinion of what you must do, with just a little effort and some testing I can show you that much of his "data" regarding airflow is just plain wrong.

[Larry Frank]

As John Lanciani has mentioned, instead of using questionable numbers, why not take him up on his offer. It would be great to see some more real world numbers instead of the ones that make no sense.

My Dust Collector max static pressure is about 12-13". Given the above numbers with 10 feet of 4" flex hose, I should not get any flow. I attached 10 feet of 4" flex hose and measured the flow before and after the hose. The flow went down from 746 cfm to 722 cfm . The static pressure went up from 9.3" to 10.0".

How about some more people run some tests and report about their system and measured results.

[Josh Kocher]

Despite your suspicions on Pentz's data, if it's overly conservative I don't mind using it as a guideline.

So throw that out if you like.

The title of the thread is "Best Practice"...

I would say that if you want to move air into that new cyclone and get the best collection you can, 4" duct is not "Best Practice".

[Josh Kocher]

As John Lanciani has mentioned, instead of using questionable numbers, why not take him up on his offer. It would be great to see some more real world numbers instead of the ones that make no sense.

My Dust Collector max static pressure is about 12-13". Given the above numbers with 10 feet of 4" flex hose, I should not get any flow. I attached 10 feet of 4" flex hose and measured the flow before and after the hose. The flow went down from 746 cfm to 722 cfm . The static pressure went up from 9.3" to 10.0".

How about some more people run some tests and report about their system and measured results.

With 9" of static loss Laguna says 200cfm in their charts for the OP's collector.

10-20 bucks more to get 5" or 6" flex for your short run, why are we even having this debate? What's the downside of going bigger? To spite pentz's numbers?

[Larry Frank]

What is the downside of going bigger? A couple of thoughts is that you need to change the port on your machines and some of them it is not really possible. Secondly, I am not going to cut into a new machine and make a new port unless that it makes a substantial difference. And, lastly, a 6" hose is much more difficult to move around than a 4" hose. I have a 5" hose going to a couple of my machines and then reduced to a 4" at the machine. The hose is much heavier and difficult to move around.

I have no idea where someone got the numbers for the static pressure loss of the hoses. I just went and used the Pentz calculator to look at the static pressure loss for 4", 5" and 6" hoses that are 10 feet long. I took the numbers from the area where he shows the subtotals for different parts of a system so that I could isolate just the hose loss.

For the 4" Flex hose, the calculator provides 5.91" of loss at 600 cfm and not the 15" that someone posted. I should have questioned the results that someone posted earlier as they just seemed wrong.

For 5" hose, the calculator provides 1.93" and for 6" hose provides 0.77" One should note that the static pressure loss is also a function of the air velocity and it goes down as the hose size goes up.

I checked these numbers with a different calculator and got similar results.

I have no problem with Bill Pentz and his numbers as he has provided a service to us all. His number and calculator seem fine. His spreadsheet is a starting point for many of us to understand what is happening.