Central Shop Vac System

[Peter Aeschliman]

Hi all,

In addition to my cyclone DC system, I'm thinking about putting in some kind of central vacuum system. I'm tired of rolling around my shop vac/dust deputy cart all over my shop. It's bulky and always in the way, not to mention super loud.

I use my shop vac for sanding and clean up. I'm also considering using it for my sawstop TS's blade guard connection (it's currently connected to my DC with a 2.5" hose dropped from the ceiling). I'd like to build a closet for both my cyclone and my shop vac to keep the noise down.

-Are there any innovative solutions out there?
-How do I figure out an appropriate size for the vacuum? I have a Rigid shop vac right now that had good suction, but once I put the Dust Deputy mini cyclone in front of it, I noticed a meaningful drop in vacuum. I imagine it will only get worse if there's ~50ft of ducting added on.
-Any other guidance or thoughts about the idea?

Thanks in advance!

Peter

[Lee Schierer]

We have a central vac system in our house. The Drain Vac Little Giant unit we have is really powerful. We purchased it from Think Vacuums. I would suggest adding a cyclone separator in front of the unit to catch the bigger stuff so you don't fill up the bags quite as fast if you are going to use it in your shop.

[John Donhowe]

I'll give you my thoughts- free and worth every cent. I am by no means an expert, and what follows what I've gleaned from personal experience and browsing web sites.

A shop vac just doesn't have enough power to support a central dust collection system. I'd recommend you look into getting an actual DC for that. A DC and a shop vac are really two different species. The shop vac can produce a high vacuum, but at a relatively low air flow (cfm), whereas a DC can create a high air flow, but at a lower vacuum. Each has its uses in the shop: the vac is good for dust pickup from tools with small dust ports (<2"), usually hand tools such as routers and hand held sanders. A DC is best for stationary tools with larger (4"+) ports- table saws, jointers and planers.

With either one, performance will diminish the more resistance you have to air flow in the line. Resistance is through long a/o narrow hoses or ducts, and anything that will increase air turbulence, such as corrugated hose, sharp bends, and cyclones (i.e. Dust Deputy). The advantages of the Dust Deputy outweigh the penalty you pay, IMO. However, adding 50' of duct or hose would really sap the power from the vac.

I'd look on CL for a used DC- Grizzly, Jet, Delta, etc., around which you can plan a fixed system (closet, duct work, etc.). Ducts should be a minimum of 4", but if you're looking at a 50' run, move up to 6" for a main trunk line. Branches to individual tools can match their port size, typically 4" for most hobbyist WW tools. Consider making a two stage system by making a Thien separator (check out jpthien.com, if you haven't already), or buy a Super Dust Deputy. I'd also recommend getting a good quality canister filter for the DC, if it doesn't have one. Size-wise, you can get by with a 650-750 cfm DC if you have short duct runs. If you're looking at 50', think about a 1100+ cfm DC. More powerful DC's would need 240V, though. BTW, the Harbor Freight DC seems to be a popular low cost choice, but you need to take their performance claims with a ton of salt.

You'll still need your shop vac for hand held tools and general shop clean up. I, too, find the high pitched whine of my Ridgid vac really irritating. I built a cart which has an enclosed box one one side to contain my vac- essentially a rolling closet. The box is lined with scrap foam rubber to cut down noise, and baffled on the bottom to vent. A hose through the side of the box connects to my Dust Deputy on the open side of the cart. By rolling the cart to where I need it, I can keep the hose length down, so as not to drain too much suction.

BTW, I find the noise of a DC much less irritating than that of a shop vac- the frequency is much lower. You might find that if you put your DC in a far corner of your shop, you might not need to build a closet.

Good luck.

John

[Phil Thien]

Peter, I have a couple of these:

http://www.leevalley.com/US/wood/pag...97,62604,62594

The ones I have were actually sourced from Rockler (which doesn't carry them any more). Woodcraft has the same thing. I wanted one and noticed a couple in Rockler one day and asked how much they were. The sales guy said something like "forty-five." I said, "I'll take two." They rang-up at $99 or $129 each and I told the guy it was okay, I'd let him back out of the sale but he insisted it was his mistake and they'd sell it. I told him it was alright and he insisted.

ANYHOW, I used those kits to create a network for my shop. All my tools have 2.5" or smaller ports. I have one of my separators in a corner, powered by a Ridgid 6-HP vac. I'm very happy with the result.

I'm not making any representations that my system gets everything. BUT, it keeps up with a 6-1/2" jointer, a 12" planer, two bandsaws, a desktop CNC router, table saw, and router table (with downdraft).

I have a rather awesome air cleaner that gets the finest dust.

[Phil Thien]

I'll give you my thoughts- free and worth every cent. I am by no means an expert, and what follows what I've gleaned from personal experience and browsing web sites.

I think you missed the part where he already has a large cyclone-based DC system. This is in addition to that.

[Peter Aeschliman]

Thanks guys. John, sorry if i wasn't clear. the purpose is to use it for my sander, the blade guard on my table saw, for other small tools, and for general shop clean-up. My 3 HP cyclone with 6" ducting does the heavy lifting.

I'll look into a bigger vacuum made for powering a home system. I figured the shop vac wouldn't be enough. What about sizing a cyclone for this then? If I get a high powered system, will my dust deputy cause problems?

[Ed Weiser]

Hi Peter,

When I set up my current shop I looked on Ebay and found an off brand central vac unit with high SP (>100 in Water IIRC) and reasonable airflow of about 80 cfm. I put a steel Dust Deputy to catch the chips before the vac unit and have run at least 100 ft of 2" pvc central vac pipe in the system. Despite at least 5 or 6 outlets, I have plenty of airflow and strength of vacuum to do any tasks I ask of the system. Like you I also have a central dust collector for large volume flows. I use the central vac system for the dust collection for my Kapex (among other tools) and get better results than I do with my Festool vac. (I think it's the bigger air hose.) In summary, my advice is don't use a shop vac but use a dedicated central vac unit.

Good luck.

[Mike Chalmers]

Isn't it about time someone comes in to decry all of this "foolish" talk about shop vacs and duct collection, as it is not approved by Mr Pentz.

[Ed Weiser]

Isn't it about time someone comes in to decry all of this "foolish" talk about shop vacs and duct collection, as it is not approved by Mr Pentz.

For high SP low flow applications they work! Festool has made that clear...

[Peter Aeschliman]

Isn't it about time someone comes in to decry all of this "foolish" talk about shop vacs and duct collection, as it is not approved by Mr Pentz.

Is this sarcasm? My reply depends on your answer.

[Lee Schierer]

Is this sarcasm? My reply depends on your answer.

Let's tread carefully here....

[John Donhowe]

Peter- my bad- when you referred to your cyclone, I thought you were referring to your Ridgid-Dust Deputy set up Doh!

In the words of Emily Litella, "Never mind!"

[Peter Aeschliman]

Let's tread carefully here....

I simply don't know whether he was being serious or sarcastic and so didn't know how to respond. It's easy to misread tone in written form, so that's why I asked.

If he was being sarcastic, we have a good laugh and we move on. If not, then I would ask Mike to clarify what issues he has with the discussion or my plans. That's all. No hostile intent- not on my part at least!

[Alan Schaffter]

I have a central vac in my shop (in addition to a DC).

It has ports for (1) cleanup vac hose (2) hollow chisel mortiser (uses Loc-Line semi-rigid pickup) (3) mitersaw blade guard (4) power hand tools (ROS, routers, biscuit jointer, etc.) via an overhead drop at my bench.

It is plumbed with relatively inexpensive 2" (gray) PCV electrical conduit which comes in long lengths. Everywhere possible I used matching long-sweep conduit elbows which have a much greater radius than PVC plumbing fittings, however I also used some plumbing (Y, etc.) fittings with shorter radii as well.

Unlike my fully-automatic DC which has machine triggered auto-gates, I used standard manual plastic blast gates for the shopvac installation. I added a contactor with a low voltage coil and pushbutton switches at each drop to turn the system on and off.

I used a standard Shopvac (brand) which provides plenty of SP. Like all shopvacs, don't expect any sort of CFM (most pull only around 100-150 CFM). I enclosed the shopvac in a lower shop cabinet to get it out of the way and reduce the noise. The cabinet has a muffled vent. At the request of AWW magazine (it was the subject of a Shop Tip a few years ago) I measured the cabinet temp for a period of over 30 min. The temp never got above 95°. I never got around to insulating the inside of the vac cabinet

As far as using a "whole house" vac system- compare the SP and CFM stats, it might not be worth the cost. The best you'll likely see from a shopvac is an SP of 100". I'm not certain, but don't think you'll see much higher than 120" for a whole house vac. The top-of-the-line Beam ($$$) claims 124" although lesser units in their line claim 140" (with 125 CFM). As far as CFM, I won't swear to this, but think the best you'll see from a generic shopvac might be 180 CFM; from a whole house vac, maybe 200 CFM, though the top-of-the-line Beam claims 211 CFM? The top of the line "Shopvac" brand claims to pull 185 CFM (sure it does!?!?!!?) and 64" (zero flow); the Fein Turbo II, 116 CFM and 90"-99". Festool claims 137 CFM and 96" for their $800 CT36. These companies often play fast and loose with numbers and you need to understand how they take the measurements. The CFM measurement is most likely taken at the inlet without hose/duct, just as the SP is measured without flow! (the old "lift the bowling ball" advertisement). Horsepower ratings are typically total BS- a theoretical number based on instantaneous measurement of current.

A Clear-Vu mini-cyclone sits outside of the vac cabinet and is connected to the inlet of the shop vac. The system works great for its intended use!!

You should be able to view this thread about it on NCWoodworker as a visitor without joining.

[glenn bradley]

In my experience, your success will depend on your shop layout. My shop is a pretty simple rectangle and my machines and work areas are laid out so as to allow a pretty open workflow. I have a large Ridgid vac / Dust Deputy about mid way along one long wall. I use a 35 - 40 foot 2-1/2" hose that is of the type that holds its shape under vacuum. That is; it doesn't try to suck-up to its minimum length under load and therefor 'snag on' or 'knock over' items between you and the vac ;-) This reaches almost everywhere in the shop although I do add another 6 feet of reduced hose when doing extended clean-ups once or twice a year.

This is the rig I settled on after a few variations of ducting did not work for me. Your vac and duct path availability will contribute directly to your success. It just wasn't in the card for me.

Ridgid Vac Mad v1 (8).jpg . Dust-Deputy-003.JPG

My dad, on the other hand has his shop setup like a maze. His solution is four smaller vacs. One on the wall by the milling machines and large bandsaw, one in the corner by the sharpening station and small bandsaw, one by the tablesaw and router table and another at the end of the lumber rack that also covers the lathe. Neither of us has had much success with rigid ducting of any length for a shop vac. The machines are just not built to move the original capacitive air mass and then perform very well. You mileage may vary.