Is a 1.5 HP cyclone enough for my garage shop?

[ChrisA Edwards]

I may be the odd one out here, I read these threads with interest and hope to enlighten and educate myself a little, but some of these dust collection threads leave me amazed that my little 1.5hp, converted two stage, dust collector actually manages to suck up 99% of the waste cut off my projects.

My main run is 5" metal, about 4' across my garage ceiling, going to 4" at the blast gate with at 15' of 4" flexible hose going to my tools.

I use my little DC with my SawStop, Hammer A3-31 J/P, ShopFox molder, Laguna Bandsaw and SuperMax Drum Sander.

I catch cuttings and sawdust into a 55 gallon drum, beneath my Oneida Super Duty XL Cyclone.

I have thought about a more powerful DC, but haven't seen the need. I've never had a duct p clog or even the narrow area of a blast gate.

[Allan Speers]

Yeah but Chris, how's your air quality?

You are no doubt sucking up all the big stuff. The important question is, are you getting all the microscopic fines? That's what does the real damage to your lungs.

Maybe you're fine, but all data suggests that you probably are not. Personally, I plan to use a HEPA respirator while running my new 1.5 HP Cyclone. I'm also considering adding true HEPA filters to the output of my two JDS air cleaners.
The cyclone will give me the convenience of minimal filter cleaning, but I'm not expecting TRULY clean air.

[Allan Speers]

BTW- That's a great idea for small clamp storage!

[Mark Daily]

Hi Allan- I’m a new forum member but have been woodworking in my 12’x 20’ garage shop for 20 years or so. I’ve been using a Grizzly G1028Z, 1.5 HP collector with .3 micron filter bags for that entire time. I have 4” flexible ducting for my main trunk and all branches to machines. I have a 12.5” planer, 6” jointer, 3HP cabinet tablesaw, 14” bandsaw, etc. and have no problems collecting dust from them, one machine on at a time using blast gates.

I also have have a Jet AFS-1000B air cleaner hung from the ceiling and together they keep my shop really clean.

To design my system I read “Dust Collection Basics” by Woodstock International which lists things such as required CFM and static pressure for various machines. It covers just about everything you need to know to get started.

As others have mentioned, things like CFM and static pressure and more important than horsepower.

Hope this helps!

[Peter Christensen]

Normally I'm all for books and the information they hold but you should understand that the 3 or so books on home shop dust collection were published 25 or more years ago. That was before the dangers of fine dust was dust was known or understood. The books were written using decades old information from industry on what was needed to remove the bigger particles of dust. Those machine port sizes, duct size requirements, flow requirements for particular machines are out of date.

I do want to welcome you Mark and not discourage or disparage you but dust collection/protection is one of the most important things in the workshop but is the most misunderstood. It should be simple and straightforward. Unfortunately it isn't though.

[ChrisA Edwards]

Yeah but Chris, how's your air quality?

My response was more to your thread title and my intent was to question is bigger really necessary for a limited space shop.

I wear a respirator while cutting and sanding, etc., I don't think any DC, attached to a tool is going to be 100% at catching the very fine stuff.

My biggest offender is my table saw. I don't use a blade guard, primarily because I like to use my cross cut sled whenever possible. Since I've started using a thin kerf blade, I end up with a lot more sawdust above the table, which means there is also finer stuff in the air. I'm working on an overhead hood that will work with my sled, for that I may need a bigger DC air flow capacity.

I also have a Jet Filter, mounted up on the ceiling for air scrubbing, although
i've read reports that this is not the ideal location as it will flow the fine stuff up and past your face.

If air quality is your major concern versus a clean, dust free shop, to the naked eye, a good respirator is the best approach.

[Jim Becker]

Allan, most of my drops are 5" with a few at 4" "down the line" for things like the router table, CNC, etc. No worries on the size. Flex should always be kept to a minimum, however, as even "smooth bore" flex has more resistance than hard duct.

[Mark Daily]

Peter, I’m not exactly sure what your point is. This particular book mentions the hazards of inhaling fine, suspended dust particles several times and recommends using an air cleaner and dust mask in addition to a dust collector.

Machines still come with 4” DC ports, so are you saying the guidelines for CFM and static pressure are no longer valid? If a DC pulls in large particles it will also pull in smaller particles. To my thinking, the issue is in how well the DC filters the air before leaving.

Thats why I mentioned my DC has .3 micron filter bags (instead of the standard 30 micron bags) and I use a ceiling mounted air filter.

I’m no expert so if I’m missing the point, please enlighten me.

[Peter Christensen]

Manufactures don't make to the best. They make what is easy and what they have always done and are reluctant to change unless forced by legislation or by the market. As the market is poorly educated they don't demand 6" ports on the machines so they aren't generally available. A 4" pipe can pull a little over 400cfm with the usual DC and less through hose. A 6" can move 800cfm to 1000cfm which is needed to pull the very fine dust that you can't see. That dust won't get picked up by a 4" hose when the bigger visible dust does. You can't see the fine stuff and it needs volume to get it. The better the filter the better it keeps the fines out of the air so that is good. There is more resistance to flow with a fine filter and that affects how much will get picked up in the first place. It isn't only the size of the port going out but there also need to be openings in the right places to allow the air to flow through to pick up the dust in the machine. That is rarely provided. So yes I am saying the guidelines in those books are outdated.

A room filter is grabbing dust out of the air that you didn't get at the source so you have to wear a good mask to protect yourself until the dust count is lowered to safe levels. How many people have dust particle counters to know when the air is clean again? Not many even though the prices are coming down to the cost of a few cases of beer. A lot of people don't know that that fine dust can hang in the air until the next day so half an hour or less after machining or sanding they pull their mask off and work in the dust for the rest of the day.

Better than filters is exhausting the collected air outside. Great in warm climates. Not so great in very cold ones like mine in the winter or extremely hot ones. Better than room air filters is ventilation where you blow the air outside with fans but that also has the temperature issues.

Something else about manufacturers and their specs. The dust collector makers test their machine to an outdated industry standard too. They take just the impeller without filters or ducts or cyclones and take a single reading in the middle of the airstream/centre of the pipe where the air flows the fastest. That is what they publish in the brochures. They don't measure across the entire pipe to get an average flow nor do they do it with the filters etc on because that further reduces the airflow making their DC look bad against the competitors. Same as car makers and their horsepower claims. In the real world that DC with 1200cfm in the brochure is going to give you an actual flow of nearer to 600cfm.

I've been reading about dust collection for decades and have a good understanding of it and I left the ideas of a 4" system with air cleaners behind long ago. I am working towards a system (CV-Max) that gets the dust at source so I won't have to have room cleaners or wear a mask unless for the worst operations. If you are happy doing so then carry on. The information is out there if you want to take the time to sift through it all.

[Allan Speers]

Allan, most of my drops are 5" with a few at 4" "down the line" for things like the router table, CNC, etc. No worries on the size. Flex should always be kept to a minimum, however, as even "smooth bore" flex has more resistance than hard duct.

Thanks, Jim.

[Mark Daily]

Peter, thanks for the info. You made a number of points I hadn’t thought about, like mfr’s still using 4” ports just because it is economical to do so- not because it works. And exhausting outside instead of in the same room- makes perfect sense, but I probably didn’t think about it because it’s not an option for my machine or my garage.

Looks like I need to do more research and start upgrading my system- thanks for your input amigo!

[Andrew More]

Something else about manufacturers and their specs. The dust collector makers test their machine to an outdated industry standard too. They take just the impeller without filters or ducts or cyclones and take a single reading in the middle of the airstream/centre of the pipe where the air flows the fastest. That is what they publish in the brochures. They don't measure across the entire pipe to get an average flow nor do they do it with the filters etc on because that further reduces the airflow making their DC look bad against the competitors. Same as car makers and their horsepower claims. In the real world that DC with 1200cfm in the brochure is going to give you an actual flow of nearer to 600cfm.

I don't think it's universally true, and instead varies depending on the manufacturer in question.

I put a lot more faith in the performance graphs that Grizzly puts out because I was able to measure the performance of the cyclone I own, and saw that the numbers claimed matched the numbers in my real world application. Further the provided graph indicates performance drop offs as the static pressure increases.

Even Bill Pentz states that "Jet and Powermatic brands actually advertisted airflows that we could get during our testing", and he's pretty hard on other manufacturers for making exaggerated claims.

Do you have some sources, or know which brands have 100% drops in performance?

@Chris - I think the proof is in the pudding, do you find fine dust on the surfaces in your shop? If not, you're good. You could also buy a air quality dust meter on Amazon to test as well. Just be careful to check the air outside your shop before worrying about it too much. Depending on where you live you could find it's nicer inside the shop than outside on some days, even with all the sawdust flying.

[Jim Becker]

Andrew, it's the fan curves that are important. They are hard (or impossible) to come by for the mass market products. Oneida has always supplied them and I believe CV does, too. It's good to hear that Grizzly is also providing fan curves as they are the only way to actually compare performance between alternative machines as well as to understand the likely performance with the duct work and tools in our own shops.

[Andrew More]

Andrew, it's the fan curves that are important. They are hard (or impossible) to come by for the mass market products.

Sorry, what's a "mass market product"? Dust collection is a niche tool, as far as I know it's not possible to buy one at any of the big box stores. I also don't see much at the local Woodcraft or Rockler, maybe a single stage collector or two. So I don't think there is a "mass market" dust collector.

Oneida has always supplied them and I believe CV does, too.

I think Clear Vue stopped providing them online, but I found an old post from 2012 with the specs. Clear Vue Fan Curve.pdf

The CV1800 starts at ~1500 CFM at 5" sp on a 6" pipe, which is overkill, IMHO, for a small hobbiest shop. I understand you can't be too careful, but the requirement is 1000 CFM at the tool, and 1500 CFM is 50% more than is necessary. Even this mythical 1000 CFM is a bit too much for most systems according to the research Bill Pentz has posted, with 800 being closer, and 1000 only necessary for Belt Sanders, and Shapers.

If it was a few dollars more, I could see going with the more powerful system, but that $1000 over the G0443 is about what Steve Ramsey suggests people spend to equip an entire shop. Not to mention the reasonable results achieved with an even cheaper single stage collector like Chris has posted. Naturally this is a trade-off everybody needs to do for themselves, but the difficulty in finding the fan curve makes it difficult.

All of which ignores the near impossibility difficulty of collecting the fine dust when it's sprayed by the fast moving blade on a table saw, or enclosing a miter saw and still having it fully functional.

In the case of the Grizzly I found it in the manual, they also seem to publish it in their spec list for their cyclones. They don't publish it for the single stage collectors, but there's little reason to do so, since the expectation is that those systems will not be ducted, instead rolled around to each station as necessary.

[Peter Christensen]

Thanks for the Clearvue pdf Andrew. I'm setting up a Max so now have something to compare.

You asked "Do you have some sources, or know which brands have 100% drops in performance?"

No not specifically. My point was that the claims can't always be trusted.

Oneida and Clearvue are generally trusted for publishing accurate air flows. It doesn't matter if you think they are too big for our home shops or that they are not single stage, just that the airflow for a 5hp is close to true. That said look at the specs of the single and double stage collectors and some claim 2hp units matches the 5 hp Oneida or CV. They also claim a 3 hp exceeds the airflows. I just don't see how honest sellers can say their 2hp collectors are as good as a 5 hp machine, that's why the stubble on my shaved head bristles a little when I see those claims.

Busy Bee Tools here in Canada, cousin to Grizzly, claim 1700cfm from a 2hp single stage. https://www.busybeetools.com/products/dust-collector-2hp-w-canister-csa-cx400.html (don't know why the link isn't working). Their 3 hp single stage claims 2320cfm. https://www.busybeetools.com/product...csa-cx402.html

Grizzly also has at 1700cfm for their 2hp DC. https://www.grizzly.com/products/Gri...Series/G0548ZP and their 3hp also claims 2320cfm just like Busy Bee. https://www.grizzly.com/products/Gri...Series/G0562ZP

Not every seller makes the same kind of claims but the average woodworker starting out doesn't have much knowledge to sort through the good and bad. They trust the sellers and are in some cases going to be disappointed or endangering themselves because they breath dust they didn't know wasn't being captured.

It would be nice if an instrumented test duct was available for a reasonable price. Clubs could buy one along with a particle counter and the members could test their systems as they make improvements. I think that would go a long way to informing woodworkers and might even get the sellers to up their game for the better.