Confused about Dust Collection

The price is right…with an HF coupon it would be $160 and just pick up at the store down the hill. However, there are lots of bad reviews mixed in with the good reviews…some really bad. Is 5 micron good enough?



Is a cartridge better than bag? Grizzly has a 1hp with cartridge for $325. It seems the cartridge alone is half that amount.



Oneida shows Dust Deputies added in parallel with what seems to be shop vacs can increase the airflow; is it enough of table saws?



Are the big dust collectors too big for handheld tools?

Do you mean vent outside without a bag or filter? I don't thing so. It would either be going under the deck or into shrubbery, neither sounds like a good idea. Plus the noise to neighbors would be greater.

For reference, this is the $800 delivered Grizzly 1hp with canister, cyclone, and remote control:



The Jet uses some sort of funky cone in a conventional cartridge unit but claims cyclone results.







The HF or single stage Grizzly would probably need a cyclone of some sort. Grizzly has one that goes on a garbage can for $35. An Oneida Super Dust Deputy is around $200 plus you need to add and modify a cannister.



They also have a setup for three regular models with two shop vacs.



The HF has a 4" inlet port, which seems strange given its rated power and airflow. I thought most vertical filter above collection systems used 6" ports. The outlet from the Super Dust Deputy is 6".

I just waded through the Bill Pentz sonnyr referenced above. It is also linked by the filter site Cole Tallerman linked above.

Now I understand why I'm confused. All our filters are awful and many more hazardous than our tools. SawStop may protect our fingers, but we are poisoning ourselves with fine dust the size of bacteria. Pentz described home woodworking shops as equivalent to third world operations generating more fine dust in the air in 4 hours than a commercial shop meeting OSHA regulations does in a year.

Loren above suggested venting outdoors. This apparently is de rigueur for commercial shops. What it is doing is dispersing the fine particles outside the workshop. Some building codes might not allow this.

The volume of air that exhausts creates another problem: low inside air pressure. This can cause flues to reverse. It is a problem with the commercial hoods in all restaurants and some homes equipped with commercial range hoods. Only a few US jurisdictions have residential building codes for makeup air. For restaurants there are significant makeup air units available to heat incoming air in cold weather. Usually, the HVAC system is also sized to include a significant part outside air. Raising 800 cfm 50°F (20°F outside) would require an 60k-80k BTU furnace.

One way to handle them may be an electrostatic precipitator. These are sold as upgrades to home HVAC systems as 'electronic filters'. They charge incoming particles and then collect them on negatively charged panels. Commercial precipitators, the size of a building, hammer the plates to clean them. Home systems require a run through the dishwasher every few months. In practice, in most home systems the electrostatic precipitators are inoperable after just a few months. One major residential HVAC vendor puts a full 4" thick fabric filter in front of their precipitator. All the overhead filters sold for woodworking are a fabric filter design (baghouse in commercial filter design).

Pentz also complained our cyclones (and how many home woodworkers have cyclones?) are too small and our filters too small, not fine enough, and and still transmit too much fine dust. They cyclone he seemed to favor was the Woodsucker models, long out of production, big, and expensive.

I'm beginning to form some ideas of a possible solutions. One would be a big indoor cyclone with the output sent outside where the filters and final collection were in a small enclosure. An blower producing the same airflow (but less powerful since it would face less resistance) would bring in an equal amount of outside air from another area far from filters. To the best of my knowledge no one makes that for home use.

The next alternative enclose the filters and with a separate blower push the air through an electrostatic precipiatotor. You could even add a catalytic filter to handle the VOCs that I'm pretty sure some of the woods and processed materials emit. None of the systems seem to have that either.

A little knowledge is a dangerous thing…and I'm more confused than ever. And I thought all the fumes from racing gas and the tires was toxic!

Note: Pentz didn't talk about electrostatic precipitators or VOCs, I added that.

I found this cyclone on e-bay. More interesting are some of the configurations.

In the first a user has it outside, and appears to blow everything that the cyclone doesn't get through a stack of automotive air filters.

In the second it seems to vent out the roof.

Nice pictures, knotscott.

Manitario, Bill Pentz has is latest info on his website: http://billpentz.com/woodworking/Cyclone/

The ClearVue appears to be Pentz's design implemented. Phii Thein complains they stole some of his design. The ClearVue is a bunch of parts connected with MDF. The parts are the plastic cyclone, a 5hp motor, a 15" or 16" impeller, and two tall filters.

They sell the parts separately-motor $375, impeller $225, cyclone $450, filters $300/$400 (either $150 or $200 each)-but the sum is high enough that it pays just to get the completed unit at $1595 or $1695 depending on the filter chosen. There is probably a hefty shipping charge on top of that, but the individual components should be light enough not to require a fork lift for unloading. Additional pieces may run a few hundred more…say $2000 total.

The Clear-Vue probably defines the upper limit of the units we have discussed here.





This is a YouTube of the ClearVue assembly, giving lots of good shots of the details:
Can an HF based unit come close? With a 20% coupon (in every issue of Circle Track magazine) the dust collector is $160. The filter from Wynn is $150-$170 plus shipping; they shy it fits the HF without issues. You can get a cyclone to fit it for $200-$250 on eBay. Miscellaneous extra parts would probably add another $100 or so for a total of about $675.

The Grizzly 1.5 hp cyclone is about $150 more, but probably doesn't include as good a filter. The Grizzly 2hp canister with the cyclone added the same way has the HF would be about the same, but again the filter probably wouldn't be as good. The cyclones look similar but the aftermarket one looks a bit better (taller cone).





Loren, his tests are interesting but his macro probably wasn't enough to see anything in the range we are talking about. I have a bellows with reversed 20mm lens to get 10x (enough to see the pixels on a TV screen). There are bellows extensions to double that. He had a simple macro lens. 1 micro is VERY small, about 100-200x smaller than those pixels.

He did talk about the air being cleaner with air blowing through a filter. A stop at Home Depot will show the filters come in a variety of strengths. The air filtration boxes that are sold are nothing more than blowing air over a filter. and could probably be constructed inexpensively using furnace filters and a modest fan.

The runtime issue for filtration is an issue. Furnaces run intermittently based on temperature. Commercial systems run to limit CO2 buildup from occupants. That isn't a residential problem because the occupancy density is much lower and the people are often at rest. However, running the house air through the filter is important if air quality is the concern. I'm not sure if any thermostats handle it. a third party does make a cycling device. It may be useful to have if a lot of woodworking is taking place in the house. Or the furnace fan can be left in the on position during woodworking and for a few hours afterwards.

Just got off the phone with Grizzly. The G0703P has a spun polyester filter and 13.5in impeller, larger than the 12.75in on there normal 2hp & 3hp units. Although rated at 1.5hp, it draws more current, [email protected] more than the 2hp unit (9A). It would be $840 with tailgate delivery, or within $100 or so of the HF with a canister filter and cyclone added. It also includes a remote control. It has a 6" inlet compared to the 4" inlet on the HF.

Based on that I would say the HF is no longer a reasonable option given the requirements for a cyclone and canister filter.



Spec sheet: http://cdn0.grizzly.com/specsheets/g0703p_ds.pdf

DYI, your progression makes sense if you start with the HF already there. The cyclone and canister are needed improvements.

Has anyone made there own air filter putting a standard furnace filter and a fan in a box? Or added the commercially available ones?

The Canadian on the link Loren posted above ran a fan on the floor through a high end furnace filter on his bedroom floor (no box) and significantly reduced the airborne particles measured and observed.



http://woodgears.ca/dust/dylos.html

Now let me add the Penn State Industries Tempests.

The design is similar to the Clearvue but more sizes are available. The 2hp (although at 9A it draws less than the Grizzly), 12"impeller (vs. the Grizzly's 13.5") is equipped with dual nano filters. $875 stationary, $895 mobile. The mobile unit only collect dust under the cyclone. After passing the filters air is re-routed to the cyclone inlet.

The 2.5hp model with a 14" impeller is $1095.

Shipping is extra, probably around $150.



These appear to be a step up from the Grizzly although more expensive and having the remote an extra $65-$75

Interestingly, they provide fan performance graphs. These can provide more insight. These are the 2hp, 2.5hp , and 3.5hp stationary models.



The 2.5hp and 3.5hp only differ in motor/blower and filters…the filters are 20% taller on the bigger unit.

They also offer mufflers that go between the filters and the blower that they reduces the noise level 50%.

HorizontalMike, how well does your trashcan separator work? Which one did you use? Grizzly has one that they charge $35 for. Sounds like an intelligent system buildup.

Crank49, you have agreed with Mike's setup. Do you have data for the pressure drop across a cyclone or the relative performance of a cyclone vs. drop out box setup like the one Mike used? In magazine reviews, such as the one in Fine Woodworking, the cyclones had little if any performance drop over use while those without had significant. The question is: where does the drop out box fall in that spectrum?

There are charts for the pressure drop across different diameter and type of ducting and ducting transitions. There are also charts for the various CFM requirements across different shop tools. Is there a chart that has the pressure drop across the tool? Grizzly has one entry that had a 2" drop from a dust hood to a 4" duct.

With a cyclone especially, there is a big penalty if the air flow drops below a required speed (fpm in contrast with volume in cfm). Some people complain their system is very loud. I'm wondering if that is because their air speed is too high. For example, 1000cfm into a 6" duct is over 5000ft/min. Penn State said their design target is 3500fpm-4000fpm with 3000fpm being too low.

"Oneida has a Smart Dust Collector in their portable line that adjusts impeller speed to maintain optimal airflow speed. However, it is frightfully expensive!



Some things I've learned.

The Grizzly 703/703P (which is $840 delivered with cart and remote) has cyclones and filters that are 1/2 the size (literally, 1/2 the size) of Grizzly's other cyclone dust collectors. A rather large difference! However, the 703 is probably enough in a small shop with only one tool active and short duct distances.

The 1.5hp 443, 2hp 440, and 3hp 441 all share the same cyclone and canister filters differing only in motor and impeller size. There is a $200 difference between the 443 and 440, but the upgrade to 220v adds $91 to the 443. The 703 includes a cart. Grizzly charges over $200 for a stand for the 440 series. There is also an optional muffler. The costs quickly add up.

The cabinet of a table saw looks like a source for a significant pressure drop…restricted inlets to the cabinet and the outlet seems to be a very primitive round hole in the side of the cabinet. I'm trying to figure how much of the drop is there.

The ratings from the manufacturers are pre-cyclone inlet…so the cyclone loss should be accounted for in those numbers. Grizzly rates their 2hp canister unit at 1700cfm (no pressure/flow graph) and the unit with a cyclone at 1350cfm, presumably reflecting the drop across the cyclone and inline with your 4" of drop estimate.

I noticed that Torit is using baghouse solutions for most of the commercial woodworking applications on their website:http://www2.donaldson.com/torit/en-us/pages/applications/woodworking.aspx. However, don't all of those systems have automated cleaning with pressurized air? Isn't that a significant difference from hobbyist shops? This is a picture of a 6800cfrm school woodshop system.



The pressure drop across the table saw, a planer/jointer, and a sanding table would seem to be an important criteria for estimating the capacity needed in hobbyist shop.

Bert, the standard hobbyist dust collector has been with a bag, maybe a cartridge, but without the automatic filter cleaning process your production shop uses. The cyclones are the only systems in the hobbyist dust collection product space that have a mechanism for filter maintenance.

Burt, what dust collector do you use in conjunction with your air filter? Do you have a cartridge? A nanofilter? A cyclone? Did you consider just putting a fan in front of a fine capture household filter like the high end 3M model, may in conjunction with their carbon filter for VOCs?





Michael (crank49), if we used an ESP after a cyclone it should capture fine particles without a fire hazard. In commercial systems, it seems baghouse solutions dominate woodworking and finer particle capture isn't an issue. But those systems are located outside. For a home system that exhausts inside that fine particle capture could be useful.

The are lots of ESPs that are sold for residential use. Like may woodshop dust collectors, failure to perform frequent and adequate cleanings renders them ineffective. However, one could be used to create an ESP for home woodshop use.

Do we have a solution for VOCs in a home woodworking shop?

My wife is sensitive to anything I paint. I have an HVLP sprayer I bought over 12 years ago. However, the drying paint emits VOCs. I think there are some paints that are lower VOC. My wife's nose is very sensitive, I lost my sense of smell about 7 years ago.

You can solve your dust capture issue, the questions are cost and local zoning. Ideally, put a significant cyclone-the Penn State Tempest S, the Grizzly G0440/G0441, Oneida V-Series or Super Gorilla, ClearVue Cyclone-outside in its own shed. For each tool ensure both the tool and hood are sufficient to capture the dust generated. Then back it up MERV 15+ filter running through a fan in the shop.

Once you put the dust collector back in the shop (The Donaldson Torit site has no commercial dust collectors in the shop) you need to have a filter capable of MERV15+, a cyclone strong enough to pull nearly everything, and motor/impeller powerful enough to drive it. This is modified HF vs. ClearVue decision is not unlike the Grizzly 1023RL vs SawStop 3hp PCS decision: both work, one provides greater safety at much higher cost.

The race car in the picture is an example. It had a bunch of safety stuff not common when it was added: collapsible steering column, extra 10lb extinguisher with thermal switch next to the fuel cell, a pressure switch set to cut the engine electrics when brake line pressure exceeded a threshold (set to 900lb, 600-650 was normal max range), the driver suit was a PBI with a very high TPP and protective underwear and baliclava were always worn (which is very hot in a stock car on a summer evening), I was using a HANS device when they were still difficult to get.

A few of those were prompted after a 2001 T-bone accident. In woodworking, unless there are fingers on the floor, the cause and effect aren't as clear.



Everything has a cost performance tradeoff. Short of spending $2500 for dust collection, it seems we are finding what the best middle ground is. For some people cost is the dominate factor. For other performance. Most of us are some place in between.

For me, the low end is probably the Grizzly 703P or PSI Tempest. I would add a cyclone and canister to the HF, raising the price to over $540. The 703P at $840 and the Tempest for $120 more offer advantages and simplicity worth the difference. Both solutions are one machine at a time with a short hose. For the table saw, that would include a flexible hose at least 12' long.

Any of the Oneidas and ClearVue would be over $1500…and approaching $2000. The Grizzly 2hp and the PSI Tempest S would both be about $1200-1300 when the dust settled (pun intended). Either should be able to handle one large machine over an arbitrary fixed ductwork of 20-50 feet. Neither specs their filters with a MERV rating and it currently isn't a nano filter.

Oneida specs their filters as MERV 15 or MERV 16, some as HEPA. ClearVue specs their standard filter as MERV 10 and has a $100 upgrade to MERV 15: Filter Efficiency: 99.99% at .5 micron (MERV 10)
Filter Upgrade: NANO - 99.999% at .5 micron (MERV 15). Presumably the PSI and Grizzly filters are MERV10 range. Those are all particle size capture numbers. They require some mechanism (e.g. a good cyclone) to keep the filter clean. And they do nothing for VOCs.

A list of the MERV standards: http://www.oneida-air.com/PDF/merv.pdf

Has anyone used the Oneida Super Dust Deputy and retrofit HEPA filter am HF or inexpensive Grizzly?

While I still may not have the right answer, the threads have been very helpful in clarifying the issue.

First, the objective. There are 2 parts. The 1st is to collect wood chips and visible sawdust to keep the shop clean and to not be wearing it at the woodworking. The 2nd is to collect fine dust from wood and wood products (such as MDF) that can be to size of bacteria or virus. That is critical to maintaining your health.

Second, commercial wood shops are significantly different than most home and some small commercial shops. These shops have their extraction systems outdoors with the makeup air provision that is significant in size. It appears that a filter system (called a baghouse system) is overwhelmingly preferred system for these commercial operations. They differ from the typical home dust collectors that use filters and having an automated system to continuously clean the filter.

Third, the only way to filter the fine particles is with a filter. The industry specifications for fine filtration are usually MERV or HEPA. For fine filtration the MERV filtration would have to be 15 or greater. The HEPA filters would be 16 or greater.

Fourth, the objective of using the cyclone is to protect the filter when no other mechanism is available to keep it clean. An effective cyclone will trap virtually all visible and most invisible particles. As long as it meets this objective the nuances of one design against the other are not important. It is like bench racing at a bar over which car is quicker; it only matters on the racetrack and then what might seem fastest on the spec sheet may not be best. And even then, the differences may be insignificant.

Fifth, and a home shop where only one tool will be used at a time the system needs to provide the needed airflow tool given the restrictions of getting her into and its dust hood and the ductwork leading from the tool to dust collector. I'm not clear on why having too much airflow will do. My guess is it will increase the vacuum in the ductwork and tool and possibly suck the sawdust out of the cyclone in its collection bin.

Sixth, the combination of a motor and impeller need to create the correct airflow through the system for the fifth objective. If they don't create enough, the system won't function adequately. If they create too much, the system may also not function as previously discussed.

Seventh, most of us have no tools to effectively measure air quality, in this case specifically particulates suspended in the air. Another discussion, air quality may also include CO2 and VOCs. So for nearly all of us we are just guessing.

So the starting point has to be to filter. Do not adversely impact the woodworkers health, that filter should be a MERV 15 or greater or HEPA filter. The larger the filter the less airflow restrictions it will create an no longer it will last between cleanings.

The cyclone needs to be effective for the volume of airflow and size of particles being captured. The cyclone actually doesn't care about volume, it cares about the velocity. I told the correct velocity is in the 3500 - 4000 feet/minute range. The equations the efficiency of the cyclone are function of the density and size of the particles, the density and viscosity of the suspending medium (in this case air with minimal compression), and the dimensions of the cyclone.

It would appear most of the cyclones are an acceptable range. Some are a little better than others and some undoubtedly have a lower pressure drop than others but we have no measurements to determine that. The relative pressure drop in the cyclone would only really be an issue if we were purchasing the cyclone independently of the motor/impeller. Except for some home built systems we aren't; instead were buying complete systems.

The smaller cyclonic systems - the 2hp/13.5in Grizzly 703P, the Penn State 2hp/12" Tempest, the Oneida 2 hp V-System - appear to be designed to be moved near the tool being used and connected directly with a short flexible duct. In that case they appear to be able to develop sufficient airflow and velocity to operate. Note that not all of these models come with a MERV 15 or HEPA filter.

The next step up appears able to handle a single (and in some cases two) tools in a modicum of ductwork connecting to the them. While I don't have definitive numbers, scrounging through the various ductwork design guides I'm guessing the back pressure through the tool to the dust collector probably 5 to 7 in/H20. To get the desired cyclone inlet velocity with a 6 inch duct that would be 650 - 800 CFM and with a 5 inch duct it would be 475 - 550 CFM. Both numbers are in the range of what the duct design guides specify for a tablesaw.

As long as they have appropriate filter and are collecting all of the dust any of the systems - whether a modified harbor freight, a home built wood cyclone, a ClearVue, or Oneida Pro-series - would be adequate.

When buying a complete system cost is an issue. I am waiting to hear back from Grizzly about the availability of their systems with nanofilters. The Oneida and ClearVue systems are nice, but also among the most expensive. In my shop, I won't be able to easily wheel around the dust collector, so the smallest systems are probably not viable. That would leave the 2hp/14" Penn State 1425 Tempest S, probably with a muffler. If the airflow is too great, I could create an additional inlet port with an automotive air filter for noise attenuation and a blast gate for volume control. If the Grizzly did come with the nanofilter, the 2hp/12.5" G0443 may be the most cost effective solution.