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What Are Jet DC-1100VX-CK Specs For 6" Connection?

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Forum topic by TimBuege posted 02-04-2020 03:32 PM 1074 views 0 times favorited 33 replies Add to Favorites Watch
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TimBuege

11 posts in 155 days


02-04-2020 03:32 PM

Hi,

I have a Jet DC-1100VX-CK in my small two-car garage shop I’ve been using it for years with just the 4” flex hose that came with it, dragging it from machine to machine. I would like to run duct work and use 6” duct for the main.

The question I have is, how can I know what CFM / FPM that dust collector will pull if I connect 6” instead of using the 4” ports? The stats on Jet’s site only list for 4” are:

Air Flow at 4” (CFM) 1100
Velocity at 4” (FPM) 12,571
Static Pressure (Wc.) 10-1/2

Is there a simple formula to convert CFM and FPM? Or is that more complex and unique to the motor / blower?

Thanks,

Tim


33 replies so far

View fivecodys's profile

fivecodys

1637 posts in 2409 days


#1 posted 02-04-2020 04:34 PM

Hi Tim,

There is a ton of information available on the web regarding DC Layouts and design and I read quite a few of them when I was designing my layout. I have the same blower that you do (Jet DC1100) and I pared it with a Super Dust Deputy Cyclone. 6” ducting is too big for this blower. The blower cannot produce enough air movement to keep all the chips and dust suspended in a duct that large. Oneida recommended 5” duct-work for a blower that size and many here have also used 4” successfully. I chose the 5” metal ducting and have been very happy with it in my small garage system.

There is some great information here: http://billpentz.com/woodworking/cyclone/ducting.cfm

Bill is pretty much the guru of dust collection. It’s a good read although confusing at times.
There are quite a few things you can do to make the most out of your system.
Long sweep elbows, reduce flex hose to a minimum, correct locations for blast gates (this one surprised me but made sense once explained). I worked hard to squeeze every bit of efficiency from my small rig.

There are some really knowledgeable folks here that are very willing to share their experiences.
I learned a lot from them.

Best wishes.

-- A bad day woodworking is still better than a good day working.

View Fred Hargis's profile

Fred Hargis

6241 posts in 3266 days


#2 posted 02-04-2020 05:39 PM

There are on on line worksheets to convert FPM to CFM a few other things that are easy to use…but you have to know one of the measurements to start. The info provided by most manufacturers for the units are a twinkle in some marketing guys eye, so you can’t rely on them. Checking the Pentz site linked above can give you some useful stuff, and it can also bury you in techno-babble…so start with the FAQ section.

-- Our village hasn't lost it's idiot, he was elected to congress.

View clagwell's profile

clagwell

246 posts in 565 days


#3 posted 02-04-2020 05:48 PM

I have not measured that DC myself but a magazine apparently has, the data was posted on another forum. I’m just not sure which magazine.

I’ve added system curves for both 4” and 6” test ducts. The maximum flow at 6” is 725CFM. For 4” it’s not quite 600CFM. Add 10’ of flex hose and those numbers drop to roughly 600 and 400.

Note that for baggers it’s common practice “rate” the CFM at about double the maximum you can actually get with no ducting.

-- Dave, Tippecanoe County, IN --- Is there a corollary to Beranek.s Law that applies to dust collection?

View pintodeluxe's profile

pintodeluxe

6155 posts in 3586 days


#4 posted 02-04-2020 05:54 PM

I have found the calculations and especially the airflow testing with anemometer to be fairly inaccurate. There are so many variables to consider.

The best thing to do is find someone that’s set up this DC unit with 6” pipe and ask them how it performs. Hopefully someone will chime in here.

I run a 2hp Tempest with 6” mains, and 5-6” drops. Everything decreases to 4” near the machine. This works great for me.

What worries me on your planned setup is twofold…
1. No real cyclone. As dust gets into the filter, suction will suffer. If you clean the filter frequently, you may be able to mitigate this issue.

2. Fan diameter. To me fan diameter matters much more than stated HP.
My unit is 2 hp with a 14” or 15” impeller. The same brand 3 hp unit has exactly the same fan curve. No difference in performance with the bigger motor. I believe your jet is closer to 11” fan diameter. The Jet website didn’t have much info on that model, but you could measure it.

I would think you’d be right on the border between 4” and 6” pipes. 5” metal mains may be the perfect solution.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View TimBuege's profile

TimBuege

11 posts in 155 days


#5 posted 02-04-2020 07:58 PM

Great feedback, thank you everyone! I’ve already taken an initial look at Bill Pentz’s website the other day. Wow, there’s an awful lot there to digest! I understand the basics of what he is saying, but I need to find some time when I can focus enough to understand the details.

I gave Jet technical support a call this afternoon, and they told me the CFM (1,100 CFM) listed in the specs for my dust collector is the same regardless whether I use the 4” port or the 6” port, since that CFM is measured at the machine. I’m not sure why the specs state that it’s CFM @ 4”. Anyhow, that’s really all I needed to know for the moment. Now I can start calculating things from there.

I plan to re-read all of your comments more closely when I have time. Looks like a lot of good information.

Tim

View ibewjon's profile

ibewjon

1630 posts in 3566 days


#6 posted 02-04-2020 08:48 PM

I have essentially the 2hp jet with pleated filter and vortex cone. I have 5”, 26 guage steel duct with long radius 90’s from Oneida. I made my own 4” y fittings with 5” main run. I am very pleased with my system. 40 feet of duct with 4 long radius 90’s, and it takes all my 8” jointer can give it. No regrets on the 5”, it seems to be the sweet spot for duct size for a 2-3 hp machine. My DC is in a corner with a run going each way. The big test will be adding another 10’ of duct and connecting the 15” planer I purchased.

View Redoak49's profile

Redoak49

4734 posts in 2761 days


#7 posted 02-04-2020 09:21 PM

As mentioned above, the 1100 cfm is a dream. The best you can get is around 700 cfm. Wood Magazine tested this DC and published the results. I do not think running 6” with this dust collector is a good idea and 5” is better.

View Scap's profile

Scap

119 posts in 700 days


#8 posted 02-05-2020 12:59 AM

1100 CFM is likely measured as free inlet. (nothing connected) Which many fan companies do. Even those that have AMCA certified performance data.

CFM to FPM is an easy calculation.
Take the area in square inches of your duct, divide by 144 to get sq ft, and divide that into the CFM for FPM.

6” = 3^2*3.14/144= 0.196 sq ft
1100/0.196 = ~5600 fpm

Once you add any duct, those numbers will necessarily drop.

View TimBuege's profile

TimBuege

11 posts in 155 days


#9 posted 02-05-2020 06:15 AM


1100 CFM is likely measured as free inlet.

Yes, this is pretty much what Jet tech support told me over the phone.

The math is not difficult, I’ve already figured that out. I just need to take the time to do some reading and plan out what I want to see if it will be feasible.

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TimBuege

11 posts in 155 days


#10 posted 02-10-2020 03:27 PM

I just received this from Jet technical support. Can someone help me interpret what it means? More specifically, what exactly does the SP column represent? The amount of SP loss at that size input, or the amount of “available” SP remaining?

What I find strange is the numbers for 4 inlet are very different than the original spreadsheet they sent me that only included statistics up to 4>

View Redoak49's profile

Redoak49

4734 posts in 2761 days


#11 posted 02-10-2020 03:45 PM

SP is static pressure and refers to the amount of suction. Higher means higher suction. It refers to how high you can suck up a column of water.

This is good information and is what is expected from a 1-1/2 HP DC.

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TimBuege

11 posts in 155 days


#12 posted 02-10-2020 03:58 PM

Thanks, that’s what I was thinking it meant. So basically, 6” inlet is essentially useless unless I’m collecting dust right at the dust collector.

My concern is the big difference in the 4” inlet statistics between the two versions of the spreadsheet that Jet sent me. The original one (test ran in 2002) shows CFM of 678 and SP of 5.56 at 4”. The newer version (test ran in 2010) shows CFM of only 223 and SP of 4.23 at 4”. Are the newer motors that much weaker? I have an older unit, so I assume mine is closer to the 2002 test.

I’m starting to come to the conclusion that this dust collector can only be used by dragging it from machine to machine. Plumbing in duct work will kill any air flow.

View clagwell's profile

clagwell

246 posts in 565 days


#13 posted 02-10-2020 05:04 PM

I’m not sure what that data is but it is NOT a fan curve as normally presented.

The most obvious oddity is the shape of the pressure vs flow curve. Bernoulli tells us that potential energy (pressure) is traded for kinetic energy (flow SQUARED). The curve is all wrong.

The next thing is flow vs motor current. That should be nearly a straight line and it’s not even close.

I’m going to look at this some more but for now don’t believe that data, I don’t care who gave it to you.

-- Dave, Tippecanoe County, IN --- Is there a corollary to Beranek.s Law that applies to dust collection?

View clagwell's profile

clagwell

246 posts in 565 days


#14 posted 02-10-2020 05:15 PM

Here’s a Wood Magazine test of the 1100A (no Vortex Cone):

Much different from what Jet provided.

-- Dave, Tippecanoe County, IN --- Is there a corollary to Beranek.s Law that applies to dust collection?

View clagwell's profile

clagwell

246 posts in 565 days


#15 posted 02-10-2020 05:32 PM

Ok, it looks like they did not calculate CFM correctly. Using the velocity data times the area of a six inch duct results in a very believable curve. In fact, the 1100M is a good match for the 1100VX I showed in post #3.

-- Dave, Tippecanoe County, IN --- Is there a corollary to Beranek.s Law that applies to dust collection?

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