94

twister testWe tested eight cyclone dust-collectors to separate hype from reality.

In the beginning, the woodworkingworld was covered in sawdust. Slowlywe evolved from broom-and-dustpan

to shop vacuum, and eventually to bigger,more capable dust collectors with the suc-tion to carry away wood chips as well as finesawdust. These days, with the health haz-ards of wood dust making front-page news,you’re about as likely to see a dust collectorin a woodworking shop as a tablesaw.

In WOOD® magazine issue #140, we testedsingle-stage collectors best suited to gather-ing dust from one tool at a time. (You can goto www.woodmagazine.com/dcreview todownload that review.) This time, we focuson cyclone systems capable of pulling dustthrough a whole-shop duct system.

How cyclones differ fromsingle-stage dust collectorsThe bag-type dust collectors most of usknow and use today are basic, single-stageunits. They suck wood dust and chipsthrough an impeller that deposits the entiremess in a lower container bag, while theair—and some dust—exhausts back into theshop through an upper filter bag. Most unitscan be wheeled from tool to tool and thenconnected directly to whatever powerequipment you’re using.

Cyclonic-type collectors are larger, fixedunits, generally more powerful, with mostrequiring 220-volt service. They suckwood chips and dust into a funnel-shapedchamber (as shown at left and described inthe caption below) where heavier parti-cles—the chips and the more substantialgrains of sawdust—fall into a separatedrum for disposal.

Numerous advantages give cyclonecollectors an edge over single-stage

units. Because cyclones separate out anddispose of virtually all the debris before itpasses through the impeller, engineers candesign the impeller for maximum airflow,not for its ability to withstand the impactof a stray chunk of wood. The impellers of single-stage collectors, on the other hand,not only have to create suction, they alsohave to transport the debris passingthrough them, which can bog them downand clog them under heavy workload.

Cyclones also can be built with big-ger impellers and motors, which creategreater airflow volume (rated in stan-dard cubic feet per minute, or SCFM),and with larger inlet ports to allowlarge-diameter, multi-duct runs. Withthe proper setup, a cyclone may be ableto serve several woodworkingmachines operating at the same timewithout sacrificing performance.

Five comparison points for cyclone collectorsTo ensure that our testing would be fair across arange of units with different specifications andoptions, we enlisted the assistance of Dr. Greg Maxwell, an airflow expert from IowaState University. (Although our test numbersmay vary from the manufacturers’ quoted specs,all of the cyclones were tested in the same man-ner, so our results give you a fair head-to-headevaluation of each machine.)

Three key criteria define the performance of acyclone dust collector: airflow, filtration, anddebris separation. In addition, we think the over-all size of the unit, and what exactly you get foryour money are important to your buying deci-sion, so we’ll touch on those subjects as well.n Airflow. Generally speaking, your dust col-lector must pull a high volume (SCFM) of air at

1

2

4

5

6

SEPARATING BY CYCLONE. When dust and debris enters the cyclone collector through the inlet (1), itbegins a spiral descent along the inside wall (2), which slows its speed. As the particles slow, largerdebris falls from the air stream and into the storage drum (3). Small dust continues to flow upwardthrough the outlet tube (4), into the impeller (5), and finally is exhausted out to the filter (6), whichremoves nearly all of the fine dust before returning cleaned air to the shop.

3

WOOD magazine December 2003TR-0015

95

Pleated cartridge filters pack more filter surfacearea into a small package. Oneida’s (left) cleanseasily by blasting it with compressed air; PennState’s filter has five times the surface area, but itsclosely spaced pleats take more time to clean.

the tool despite static-pressure (SP)loss caused by ductwork betweenthe tool and the collector. (See“What is static-pressure loss?” onpage 97.) Using a pitot tube andmanometer, we recorded SCFMreadings at a series of SP levels inductwork matching each unit’s inletdiameter. The Cyclone PerformanceCurves chart, on the next page, plotsthe airflow through each inlet as wegradually dialed in a funnel-shapedplug (shown in the photo above) toincrease SP. All models used their factory-supplied filters, which wereseasoned with 30 gallons of wooddust and then emptied prior to thetest, to provide real-world results.

Reading the chart from right toleft, you see that as static pressureclimbs, airflow drops. Oneida’s 2Commercial System pulled thehighest volume of air across awide range of SP, with Grizzly’sG0525 second best.

However, at very high static pres-sures, the Penn StateTEMP142CX delivered high-er airflow. So, if the SP losson your shop’s ductwork isless than about 7", the 2Commercial and Grizzlyperform best; ductworkwith greater than 8" SPloss (a pretty extreme con-dition) would be betterserved by the Penn Statecyclone. Most stationarywoodworking powertools require at least 350SCFM to adequatelyevacuate dust, so at over9" of SP even theT E M P 1 4 2 C Xbecomes ineffective.

Remember, too,that opening theductwork to twowww.woodmagazine.com

machines at a time requires twice the air-flow and can nearly double the SP, depend-ing on the configuration of your ductwork. n Filtration. When it comes to filters—the cyclone’s last line of defense againstfine dust—consider both the level of filtra-tion and the filter media itself. All of themanufacturers represented in this test haveswitched to high-efficiency cartridges (seephoto, above) or bags that capture virtuallyall of the dust particles most harmful toyour respiratory system—particles thatrange in size from 0.5 to 10 microns.

Besides protecting your lungs, these high-efficiency filters also can improve airflowthrough the system. For example, Bridge-wood and Grizzly first sent 30-micron bags(common on single-stage dust collectors)with their cyclones, and then changed tohigh-efficiency bags midway through ourtest. Retesting these machines with theirnew bags gained them an average of 175SCFM and 1" of static pressure.

As for the filtration media itself, celluloseor paper-type cartridge filters perform aswell as more costly spun polyester filters—although the synthetics have the edge inmoisture- and puncture-resistance. A steelmesh protects Penn State’s cellulose filtersfrom projectiles, such as a mitersaw-flungoffcut. Cartridge filters also provide a larg-er surface area for filtration than cloth bags.That means they restrict the exhausted airless and take up less space in your shop.n Debris separation. To test howwell each cyclone separates heavier dustand debris from fine dust, we diligentlymixed and weighed equal piles of woodchips and sawdust, and then fed the sameamount at the same rate to each of the col-lectors. Ultimately, we found negligible dif-ferences in the way each cyclone separatesmaterials.

But what do you do with that drum whenit gets full? Units that collected the debris in55-gallon drums went longest betweenemptyings, but those drums are awkwardand heavy to lift and dump (although both55-gallon models in our test come with a

96 WOOD magazine December 2003

High pointsd Three-way adapter instantly reduces 8" inlet

to three 4" inlets, or can be left off for a full8" main.

d Rolling drum dolly makes haul-away easier,and large drum size eliminates frequentemptying.

d Fairly easy assembly.

Low pointsf 10' height means it won’t fit under a

standard 8' ceiling.f Owner’s manual doesn’t list some assembly

steps at all, and lists others that are no longer necessary.

More pointsg 55-gallon drum not included.g Bridgewood also sells a 5-hp version

(model BW-CDC5), requiring 30 amps at220V for $1,095.

High pointsd The second-highest airflow and a compara-

tively low price make this cyclone our Top Value.

d Three-way adapter instantly reduces 8" inletto three 4" inlets, or can be left off for a full8" main.

d Drum dolly makes haul-away easier, and large drum eliminates frequent empying.

Low pointsf 10' height means it won’t fit under a

standard 8' ceiling.f Owner’s manual doesn’t list some assembly

steps at all, and lists others that are no longer necessary.

More pointsg 55-gallon drum not included.g Although this unit appears similar to the

Bridgewood BW-CDC3, its impeller pulled higher airflow.

How the cyclones stack up

wheeled drum dolly to easetransportation). Smaller drumsare easier to manage but must beemptied more often. n Overall size. Cyclonecollectors are necessarily tall,and manufacturers have towork hard to make their unitsfit under an 8' ceiling (theBridgewood and Grizzlycrowded even the 10' ceilingin our test facility). Also,because space often is tight ina workshop, it helps to know acyclone’s footprint before youbuy. Those dimensions areshown in the chart on page 98.

Some units offer space-sav-ing options, such as the inter-nal filter that fits inside thecyclone on the OneidaComp-Sys models. Thetrade-off, however, is about a 10-percent drop in airflowcompared to the external fil-ter, and more difficult—andmore frequent—cleanings.Penn State’s cartridge filtercan be suspended from theceiling to save floor space.

If noise reduction is more important toyou than size, Penn State’s optional exhaustmuffler increases the cyclone’s overall foot-print, but decreases noise by 5 to 10 dB.

n Extras. None of the units in our groupwas complete and ready to run “out of thebox.” They required assembly, and wefound that some key components may or

may not be included in the purchase price.For example, collection drums add cost toall but the Oneida systems. Most also camewithout power cords and plugs, so we had

CYCLONEPERFORMANCE

CURVES

CYCLONEPERFORMANCE

CURVES

CYCLONEPERFORMANCE

CURVES

DU

CTW

OR

K R

ES

ISTA

NC

E (S

P lo

ss)

Bridgewood BW-CDC3

Grizzly G0525

Oneida Comp-Sys 2EXT35

Oneida 2 Commercial

Tests were conducted using pitot tube and manometer at dust-collector inlet, and ductwork the same diameter as the inlet. Duct length was 10 times its diameter to stabilize airflow for accurate measurements. Filters were seasoned, emptied, and tapped clean before test to simulate workshop conditions.

AIRFLOW (Standard cubic feet per minute)

Penn State TEMPEST

Penn State TEMP142CX

0 200 400 600 800 1000 1200 14000

2

4

6

8

10

Minimum recommended airflow for

Woodsucker II

Oneida Comp-Sys 1.5EXT35

1

3

5

7

9

11stationary tools

Shop #3

Shop #1

Shop #2

planers

Bridgewood BW-CDC3, $695www.wilkemach.com, 800/235-2100

Grizzly G0525, $725www.grizzly.com, 800/523-4777

After calculating the static-pressure loss of your ductwork (see sidebar at right), find the number along theleft side of this chart. Now follow that horizontal line across the chart. (We plotted the three “typical” shopsfrom the sidebar as examples.) The dust collector you choose must have a performance curve above yourhorizontal line and to the right of the 350-SCFM mark recommended for most stationary woodworking tools.

Static-pressure loss is resistance to airflow created by “upstream” factors, such as duct length and diameter, and the number—and even the angle—of intersections, bends, and elbows. There’s a realscience to minimizing SP loss (thus maximizing the performance) of dust-collection ductwork, andsome of the manufacturers represented in our test provide assistance in planning or analyzing yoursystem, for free or a nominal fee. We heartily recommend taking advantage of these services before

buying a cyclone.To help you make a meaningful comparison of the

cyclones in the test, we came up with the three “typical”shop scenarios shown at left. (Note: Although there’smore ductwork in Shop #2 than Shop #1, this system’sSP loss is actually lower because of the 7"-diameter mainand a shorter run of flex hose.)It’s unlikely that any of these scenarios will match your

shop exactly, but you can use them to “ballpark” the SPon your ductwork. Remember that adding length, elbows,and flexible hose will add to SP loss; removing them willreduce the loss. Collecting from two tools at once also willincrease SP loss and require twice the airflow.You can calculate more precisely the static pressure ofyour existing or planned ductwork by following theinstructions in WOOD® magazine issue #119 (page 16),or by visiting www.woodmagazine.com/spcalc for ahandy worksheet.

97www.woodmagazine.com

High pointsd The included 35-gallon drum mounts to and

dismounts from the cyclone easily.d Canister-filter clean-out at bottom of unit

makes emptying it a snap.d The only cyclone in the test that can easily

run on a 110-volt circuit.d Easy assembly and excellent manufacturer

support, including design assistance and acomplete line of filters, ductwork, andaccessories.

d Packaged for shipping via UPS.

Low pointsf A small pinhole leak on the exhaust plenum

allowed some dust to leak into the shop air.We patched it with a dab of silicone sealant.

More pointsg For small shops, this cyclone’s optional

internal filter reduces its footprint, butknocks about 10 percent off airflow,and makes clean-out more of a chore.

What is static-pressure loss?

Oneida Comp-Sys 1.5EXT35, $875www.oneida-air.com, 800/732-4065

High pointsd Canister-filter clean-out at bottom of unit

makes emptying it a snap.d Easy assembly and excellent manufacturer

support, including design assistance and acomplete line of filters, ductwork, andaccessories.

d Packaged for shipping via UPS.

More pointsg For small shops, optional internal filter

reduces its footprint, but knocks about 10percent off performance, and makesclean-out more of a chore.

Oneida Comp-Sys 2EXT35, $975www.oneida-air.com, 800/732-4065

Shop 1

Shop 2

Shop 3

to buy those as well. (Check the list of stan-dard and optional accessories for eachmodel in the chart on page 98.)

Sales tax and shipping also add cost,which can be considerable on large, heavyequipment, particularly with units shippedby a trucking line. Cyclones that are broken

down for shipping by UPS can save youshipping hassles and costs, but you pay withextra assembly time. It’s worth your whileto call the manufacturers or check out theirInternet sites to find out, in advance, exact-ly what you’re getting for your money, andwhat shipping methods are available.

Finally, it may be important to have helpwhen you’re setting up your system. Designinformation or assistance is available fromGrizzly, Oneida (for a $50 fee, which canbe applied toward the purchase of one oftheir systems), and Penn State, but not fromBridgewood or Woodsucker.

WOOD magazine December 2003

(*) Alternative mounting method lowersheight to 851/2".

WOODSUCKER

NOTES:

BRAN

D

FAN

IMPE

LLER

DIA

MET

ER

(INC

HES

)

AMPS

(220

V)

HORS

EPO

WER

MO

DEL

BRIDGEWOOD

GRIZZLY

ONEIDA

PENN STATE

3

3

11/2

2

2

2

2

2

18

18

8.5

11.4

11.4

8

10

11.4

13

13

121/2

121/2

14

12

14

13

MOTOR

1. Height may vary according to distancebetween drum and cone.

(S) Leg stand(W)

2.Wall mount

(S/W) Can be mounted either way

Cartridge filter with cleanout

3. Bag filterCartridge filter

(B)(C)

(CC)

BW-CDC3

G0525

Comp-Sys 1.5EXT35

Comp-Sys 2EXT35

2 COMMERCIAL

#TEMPEST

#TEMP142CX

WOODSUCKER II

4. (C)(P)

Cellulose with steel meshSpun-bond polyester

High pointsd The lowest-priced cyclone in our test.d A clean-out zipper on the filter bag makes

dust removal fast and easy.d Optional 26-gal. drum is small, but it

mounts to and dismounts from the cyclone quickly and handles easier than larger drums.

d Wall-mounting brackets come with thecyclone.

d Packaged for shipping via UPS.

Low pointsf This unit pulled the lowest SCFM in the test.f Lots of assembly work, and the manual

is disorganized and confusing.

More pointsg Also available with .5 micron canister filter

(TEMPESTCX) for $645.

Penn State TEMPEST, $495www.pennstateind.com, 800/377-7297

Penn State TEMP142CX, $795www.pennstateind.com, 800/377-7297

High pointsd Started in the middle of the pack for airflow,

but outsucked all the other cyclones at SP levels greater than about 8".

d Ceiling-mounting the cartridge filter saveson floor space.

d The largest filter surface area—452 sq. ft.—of any cyclone in the test, means less- frequent cleanings.

d Power cord, switch, and wall-mountingbrackets included in purchase price.

d Packaged for easy shipping via UPS.

Low pointsf Clean-out drum is permanently affixed to

the filter, so it must be vacuumed out through an access door.

f Closely spaced pleats inside the filterrequire patience to clean.

High pointsd The highest airflow numbers in the test.d Pleated-polyester canister filter is an

efficient dust-catcher, and a clean-out at bottom of unit makes emptying it a snap.

d Easy assembly and excellent manufacturersupport, including design assistance and acomplete line of filters, ductwork, andaccessories.

Low pointsf The highest-priced cyclone in the test.f Large size of components requires they

be shipped by trucking line, which may or may not deliver to a home address.

More Pointsg Hands down, this machine tested best,

so we named it our Top Tool.

Oneida 2 Commercial System, $1,070www.oneida-air.com, 800/732-4065

REPORT CARD

Cyclone dust collectors:Additional informationfor the “Report Card”

More pointsg The photo shows a steel filter-clean-out

drum, but Penn State changed to a fiberclean-out drum (and lowered the price) justbefore this issue went to press.

g Options abound on this cyclone, including a5-micron bag filter that reduces unit cost to$645, an excellent value.

g We tested the 3-hp version (TEMP143CC,$995) and found its performance curve identical because the impeller and motor speed are the same as the 2-hp model.However, the 3-hp motor should last longer.

g System-design assistance is available.

98

Inlet Diam.Brand Model (inches)Bridgewood BW-CDC3 8Grizzly G0525 8Oneida Comp-Sys 1.5EXT35 6

Comp-Sys 2EXT35 72 Commercial 7

Penn State Tempest 5Tempest142CX 6

Woodsucker Woodsucker II 6

99www.woodmagazine.com

The Oneida 2 Commercial has the most impressive overall per-formance of all the cyclones in the test, with the highest peakSCFM readings and the ability to sustain that airflow well above 6"of static pressure. This, plus effective fine-dust filtration and fast,easy clean-out earned this sucker Top Tool honors.

For about $300 less, though, Grizzly’s G0525 performed remark-ably well, with a high-efficiency filter bag and airflow second onlyto the Oneida 2 Commercial, so we named it the Top Value. Theonly drawback is its towering height, which, at 10', may be toomuch for many home shops. If your shop can’t handle that height,take a good look at the Penn State TEMP142. It’s the same machineas the TEMP142CX we tested but comes with a less-efficient 5-micron bag instead of the .5-micron cartridge filter, and costsonly $645. And, at only 94" tall, it fits under an 8' ceiling. ¿

Written by Michael Morris with Dave Campbell and Jeff HallIllustrations: Tim Cahill

High pointsd Unique exhaust design captures the .5-micron

cartridge filter inside a clear plastic bag so you can see when the filter needs cleaning.

d Well-written manual made bolt-together setup easy and relatively quick.

d Wall-mounting brackets, power cord, and switch included in price.

Low pointsf Large size requires shipping by trucking

company.f Noticeably the loudest in the test at 91 dB.f Not much in support services provided by the

manufacturer.

Woodsucker II, $800www.woodsucker.com, 866/366-3878

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PERFORMANCEGRADES (6)

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120 x 68 x 40

120 x 68 x 40

85 x 48 x 28

89 x 48 x 28

96 x 54 x 28

88 x 46 x 25

94 x 44 x 28

93* x 40 x 23

CONSTRUCTION

S

S

S/W

S/W

S/W

W

W

W

55

55

35

35

35

26

26

35

B

B

CC

CC

CC

B

CC

C

P

P

P

P

P

P

C

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FILTER(AS TESTED)

5

1

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.2–2

.2–2

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.5

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C

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82

89

81

83

81

81

83

91

12

12

N/A

N/A

N/A

5

6

6

ACCESSORIES (9)

DD, P, S

DD, P, S

C, D, O, W

C, D, O, W

C, D, O, W

P, W

C, O, P, W

C, W

D

D

P, R, S

P, R, S

P, R, S

C, D, M, O, R, S, U

D, M, R, S, U

D

1

1

2

2

2

2

2

2

T

T

U

U

U

T

T

U

246

246

219

238

350

125

217

165

$695

725

875

975

1,070

495

795

800

7. Measured 8' from machine at 5' height.

8. (N/A) Cord not included.

Excellent

Good

Average

Below average

6. A

B

C

D

10. (T)(U)

TaiwanUnited States

11. Prices current at time of article’s production and do not include shipping, where applicable.

9. (C)(D)

Cartridge filterDrum

(DD) Drum dolly(M)(O)(P)(R)(S)(U)(W)

MufflerCleanoutPower switchRemote power switchLeg standCeiling-mounting brackets for filterWall-mounting brackets

5. From manufacturer’s specifications.We were not able to verify this in our testing.

Our pick of the litter gobblers

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Review at

FOR EIGHT CYCLONE DUST-COLLECTORS UNDER $1,100

©Copyright Meredith Corporation 2003