Dust collection wizards...

3 hp motor-13" steel impellor-- how much suction will it produce? 8" inlet and outlet, 6" duct on all main lines..
compared to a 2hp and 12" impelllor?

I don't know about being a wizard but I would say about 1300 to 1400 cfm.

Did you get a new dust collector?

ok that would be an improvement over the 2hp setup right? and by how much alan??

Larry you will see some improvements but looking at the testing done by Bill Penze on his website I think it would be minimal. Here is a link go to the Excel spread sheet and there is a chart showing the information.

Right above the static calc table is a fan table giving approximate cfm's for given fan sizes and motor horsepower.

so as don said and alan lead me to, its not big improvement huh

Nope, If your gonna spend the money I'd go for a 16" with a 5 HP.

Although its not as simple as HP and size, if the fan was a different shape (like the 2HP was really inefficient and the 3HP was way better designed) you could see a bit of a jump. At best I'd say maybe 25% effective (delivered at the end of the pipe) if the stars aligned right. On the flip side if the reverse is true it might not be any improvement at all...

Buying dust collectors is worse than buying a bed, why yes this is definitely the most comfortable thing you'll see today.. Why are you laying down on it my good sir, don't you trust me?

Hi Larry,

A huge factor in efficiency is how you run your ducts.

Really, really, really try not to have any 90* turns. Do a 45* ell into a short coupling (translate that to 6inch length of your 6 inch ducting) into another 45* ell. It takes 3 inches of pipe to go into a fitting, so the two 45* ells use up 6 inches of pipe so they can fit coupling to coupling. You can make the coupling longer if you wish.

Do not use any more flex than is absolutely necessary.

Be sure that all blast gates, except the one you are using right now, are closed.

My set up is a 2hp PennState. With this setup I am satisfactory. I do not have ANY surplus. If a second blast gate is open, my efficiency drops like a rock. My setup is inadequate to use a "Big Gulp" type of thing at the lathe. I have to use two of the flex-duct pipes that stay in the position where I put them. That means I have to adjust them every time I work on a different section of the turning.

My bandsaws, drill press, thickness planer, sanders, table saw and router (router has its own ShopVac) all work fine.

I cannot remember the impeller size. I do remember that the amperage is low for a real 2hp motor. They claim 1,500 CFM. Don't get me wrong. I am not buying a new DC. This one works well enough to keep me happy---and I really, really, to not like wood dust. However, If I had been more knowledgeable at the time of purchase I would have purchased a gutsier unit.

I purchased the PennState (DC2000) because it had one micron bags. To me that is extremely important. It is the fine stuff you cannot see that kills you. The one micron bags ended up not really mattering because I built a shed outside of my shop to house the DC (and give me more storage).

The other factor was the price. Read the data on other DCs and compare to the PennState. With 1 micron bags 1,500 CFM etc. you will find that they have a higher price.

The "dust" on the cover of the magazine is all of the dust removed from an 18-foot section of 6 inch pipe after several years of use---everything else made it to the dust collector bag. The pic showing the three pipes joining and going through the wall is where the system leaves the shop and goes next door into the dust collector itself.

One pic shows two 45* ells making a 90* turn. Another pic shows the end of a piece of 4 inch flex that was a drop from the 6-inch to a machine. It had been used for several years.

If you have any questions, ASK.

Enjoy,

JimB

When I researched larger DCs in 2006-07, I decided on the 3hp SDG based on its rated capacity. I knew I'd be able to have 2-3 ports open at the same time with no real reduction in performance. As others have said, you do not want to use any 90° elbows; sweeps are much better (I chose sweeps over 45° pairs for fewer joints). I had to stretch the budget a bit to get the 3hp, but I phased in the ducting over the next year or so to spread out the cost.

i have one 90° and most are the Y's like you mention bill. and i dont use a bag system it goes right outside.. i am just wanting to get more suction at the drum sander..thats my worst culprit..i have a double 45 configuration and its about 4ft high..4" it goes into a 6" pipe to the outdoors. here is the line that i want more suction at..also i do have some leakage on some of the gates???

My suggestion is add another 4" dust port to the sander, run a second hose back to your 6" duct. Then close everything off but the sander.

If you don't want to modify the sander, I'd run 6" duct up to the sander, 6" flex and a 6" reducer to the sander port size.

A more minor thing, you have a couple extra 45's in there that you could live without, but I doubt that's going to make a significant difference.

jeb i think the sander is stuck with the single port but i could go up to 5 " if i did some rework but that means to do some concrete chipping as well..

Larry I used Penz's spreadsheet and looked at the amount of losses assuming a total of 12 feet of 4"PVC, 6 feet of flex hose 2 -45's and 1 90and the loses came to 19.93 " wc by changing everything to 5" your losses dropped to 7.04. If it were me I'd be getting out the air tools and start chipping away on the concrete. If you would like I can send you the excell file so you can see.

Is there any way you can run a temporary line over to see Larry? I'm not sure what hose/fittings you have at your disposal, but it would be a nice thing to test if you had parts around to do it.

To avoid digging up a line, is there any other 4" drop close to feed a second hose?

Larry here are the number from the Pentz spread sheet



as an FYI Pentz says to use each 45 as .5 of a 90 so thats why it shows 2 90's

well jeb i have another drop in to the main line after the sander and one before the one after is capped off and the before goes tot he TSaw which could be closed off to direct more to the sander.. i might be able to go and make up a 5 " line to see how it worked in comparison to the 4" setup prior to the cement chipping,, the problem with the cement chipping is to get a fitting to accept the 5" pipe from a 6" pvc main line..

Hi,

Remember, what makes the DC system work is the efficient movement of air. ANYTHING that causes a ripple in the flow of the air is going to cost you. Examples: ripples in flex, any (even very slight) change in direction of the air, anything rough inside of the ducting, etc. You not only want to move the air, you want to move the air that is going to carry your dust; another open duct will steal the air that you want to move that sander dust.

Think of the air molecules as large marbles. They are going 131 miles an hour down the straight away, then comes a little turn and the outside marbles bounce off of the duct wall and start banging into the marbles in the center, which causes them to bang into other marbles. Energy is wasted and the marbles (dust) do not move as fast, nor as efficiently --- you have less "suction."

Enjoy,

JimB

got larger pipe last night and will do some excavating today sometime,,