Is Air Filtration with .3 micron Hepa Filters possible without spending thousands?

[ed mendenhall]

Does anybody have any experience or knowledge of using hepa filters in a typical small shop air cleaner such as the jds, delta, jet, etc?

I've been doing a lot of research but just getting more confused, (same for dust collection) so I figured I would just ask directly.

The best I've seen mentioned was 1 micron at the inner filter, but most agree that .3 microns is where it's at for lung health. I can't afford to spend thousands on an industrial hepa unit for the basement. So far the only reasonable one is made by grizzly for $589 with shipping. http://www.grizzly.com/products/Large-Floor-Air-Filter/G0573 They also carry a Shop Fox fine air unit but it is only 200cfm. I've seen them for $99.

Would it do any good to buy a regular unit (1 micron) and add the Shop Fox for the really fines for a total of around $350-$400?

Or should I just build my own using hepa filters? Anyone seen or built their own? BTW, I plan to install Pentz style Cyclone as well.

Thanks,
Ed

[Kent Chasson]

If your goal is to reduce the number of small particles that you breath, I would suggest you forget the air cleaner and use that extra money and time on your dust collection (or just wear a respirator). In my experience, once the small particles get in the air, an air cleaner will never collect a high percentage of them. They filter the air close by quite well but the fan tends to spread the rest of the particles all over the shop and a lot of dust eventually settles out only to get kicked up again later. It's possible they will actually be harmful because they can make the air feel cleaner and you less likely to wear a respirator even though there are a lot of small, harmful particles still floating around.

Keeping small particles out of the air is no small task. I just spent several thousand dollars and a solid month putting new dust collection in a 600 sq ft shop and I'm still not finished. I am now able to use many of the tools without wearing a respirator but even with consistent effort and patience, I still end up wearing a respirator half the time. If I get it down to 20%, I'll be thrilled.

[David Hostetler]

filter efficiencies are a tough nut to crack for sure. For example the Wynn 35A Spun Bond cartridge filter for single stage dust collectors is rated at 1 micron, but if you look at the MERV rating, it is a higher MERV rating than the .5 micron rated paper blend model... Why is that? Part of it has to do with the testing methodology, and certification process for various filtration media.

If you are truly concerned with HEPA filtration, you might want to contact Dick Wynn and Wynn Environmental directly. Dick has worked with Bill Pentz in the area of woodworking filtration, and is a veritable library of knowledge on the subject.

Generally speaking though, your 1 micron rated filter captures 97+% of all particles 1 micron and larger, they also typically capture somewhere in the high 80% range of particles .3 to 1 microns... Combined with the multiple changes of air in a given volume, and while you will never, not even with HEPA get completely 100% particle filtration, you will get as close as you can...

Mind you, that air filter is not to be used while you are in the shop. That is NOT what they are for. They are there to clean the air AFTER you are done working, so that the next time you enter the shop, you are entering clean air... If you are worried about while you are in the shop, capture the dust before it gets airborne with a proper dust collection system, including proper separation, and filtration.... Again read Bill Pentz' work on the subject. While the subject is deep enough, and Bill goes all the way into it, so there is enough there to melt a brain surgeon's head, if you take your time and digest it bit by bit, his ideas for the most part are dead on...

[Van Huskey]

Mind you, that air filter is not to be used while you are in the shop. That is NOT what they are for. They are there to clean the air AFTER you are done working, so that the next time you enter the shop, you are entering clean air...

Although, they certainly aren't the first line of protection (removal as close to the source is) I have never heard they were not for use DURING work. The manufacturers certainly market them as such and the magazine articles testing them assume they are being used while working. It seems very odd not to use them the entire time you are in the shop. Most are designed with a timer to continue to scrub the air after you leave but I am still at a loss to understand the logic of not running them when you are in the shop, please illuminate me.

[David Hostetler]

Think about it, if you are producing dust around waist level, and you are pulling that dusty air up to ceiling level to get to the filter, what does it have to pass? Your mouth and nose. Also the air movement tends to kick up dust that has settled in the shop....Both the Wood Whisperer and Fine Woodworking had videos on the subject a few years ago... Check out The Wood Whisperer videos for video #88 I believe it was...

Having said that, I tend to run mine prior to my entry into the shop, while I work and afterwards... I know I am not supposed to while I work, but it helps keep the air in my shop cooler, and it REALLY helps the A/C move the cooled air around my shop! I don't know that it is THAT much of a danger, but if you are going to be ultra paranoid about dust, then best to avoid it as much as possible... I am trying to take the as good as possible while staying sane approach... I don't think the last bit is working too well though.

[Van Huskey]

Think about it, if you are producing dust around waist level, and you are pulling that dusty air up to ceiling level to get to the filter, what does it have to pass? Your mouth and nose. Also the air movement tends to kick up dust that has settled in the shop....Both the Wood Whisperer and Fine Woodworking had videos on the subject a few years ago... Check out The Wood Whisperer videos for video #88 I believe it was...

Having said that, I tend to run mine prior to my entry into the shop, while I work and afterwards... I know I am not supposed to while I work, but it helps keep the air in my shop cooler, and it REALLY helps the A/C move the cooled air around my shop! I don't know that it is THAT much of a danger, but if you are going to be ultra paranoid about dust, then best to avoid it as much as possible... I am trying to take the as good as possible while staying sane approach... I don't think the last bit is working too well though.

I think you are mis-applying the theory. The problem with the really harmful sized particles is that they stay in suspension in the air even with little to no air movement. I think what Marc was trying to say is it does not negate the need for a respirator. I am open to others input but my firm belief is that on balance the air cleaners make the workshop better for your lungs on a whole by running them while you work and after compared to JUST running them after. The harmful particle sizes just don't settle and ANY air movement in the shop are going to keep a significant amount of them in suspension at nose level. Take a look around after a long ROS sanding session and you will see the amount of VISIBLE particles in suspension at well above nose level, if these large particles are in suspension you can guarantee the small ones are as well in an even bigger percentage. These filters work and in my opinion not running them while you work is reducing their efficacy and increasing the particle load on your longs both small and large. In the end capture all the dust you can at the source (and make sure you are not reintroducing it) but no matter how effective this is it isn't 100% on any tool/DC system I have seen, you still have to treat the ambient air.

[David Hostetler]

I won't argue with you on that, I run mine while I work and had assumed I was doing something bad... But I figure it swaps the air how fast? And honestly, I won't get anything done if I am sweating to death in there...

So I guess I can stop feeling stupid about using my air filter while I work then?

[Van Huskey]

So I guess I can stop feeling stupid about using my air filter while I work then?

I would! If you look at the recent I think FWW test of these (where I think the Jet won) they showed the times it took each of these to reduce the fine particle size by some percentage, I don't remember the exact time periods but they were far shorter than my typical shop time. I think running them while you work is good, but assuming they keep the air 100% safe all the time is the bad idea since they don't and even if they make it WORSE for a short time (I am not sure about that given the particle size we are concerned with) on the whole they make the air safer.

[Van Huskey]

BTW this rewritten article may shed some light for the OP and others:

http://www.finewoodworking.com/fwnpdfFREE/011213054.pdf

[phil harold]

I think the OP is concerned about creating dust in his house
Shop is in the basement and will migrate into the rest of the house
I would consider venting the Pentz style Cyclone outdoors
Just need to make sure if you are pumping air out of the house with the cyclone you need to have a source of make-up air

[Carl Babel]

I strap a Filtrete Ultimate filter onto a box fan, set it next to where I am working, and work away.
This is in addition to my DC system (Oneida).

[Neil Brooks]

I strap a Filtrete Ultimate filter onto a box fan, set it next to where I am working, and work away.
This is in addition to my DC system (Oneida).

Me, too.

Lots of "us," actually, from what I've seen.

In my case, I actually go one step farther. My whole-house air cleaner uses a 5" thick pleated media filter:

http://t1.gstatic.com/images?q=tbn:ANd9GcQPkOdneSJ7fHmeL8W4opxVb0dtQmCG0 kThKJyXRRJcbt85zf_Y

It gets sandwiched on there, too, along with the Filtrete, and sits on my sanding table, while I'm sanding. It's also on a cheap Harbor Freight programmable timer, and runs, on "HI," about 3hrs, in the middle of the night.

AND ... a hanging JDS unit, and a pretty effective DC, AND ... one of these jobbies in my shop window:

http://lh4.googleusercontent.com/public/SfUZIkgEoWZtmMEGuAUmvvPxwPTkg-tPv-1QL7eHJYH-C4wXI3VVwSRHJTDIV7aKJ3adMf9TzEK3dQfKc8mtCxOaiLExBd 5S8yJAUxAS4EuFcTOsL3doab2He0FdK9bDy_dVIsI9O626nGjs v6a06A4eN5VQT12hG3ZkUVDoSR9a-WOld3Zj2iM5Q9nv

But ... because I just enjoy this DC stuff ... I picked up a used bomb-proof fan (http://www.drillspot.com/products/49532/Dayton_3XK51_Exhaust_Fan), for a hundred bucks, and am building a 30 x 30 x 30" rolling air filtration cube that will use one 5" pleated media filter, and TWO 3M Filtrete filters.

I'll install a threaded insert into the top panel, so I can add or remove a big eye hook, and hoist it into the air, by pulley on the joists, if necessary.

I'm using a 12-hr attic-fan timer, with a "hold" feature, as the switch.

I do NOT aim for an ISO 14644-1 cleanroom (:D), but ... my shop's in the basement, and want to do what I can to keep the mess at bay.

[ed mendenhall]

Hey everyone, sorry it took so long to chime in but I must have missed the check box to get email notifications for replies. I have been checking my email every few hrs with no responses (feel like an idiot) so I checked into the forum tonight. Glad I did....

Let me clarify a bit... I am setting up my first workshop in the basement. I do intend to go all out with the "Bill Pentz" style cyclone system. So i hope to catch most at the source. Of course with the expense and work involved it will be a while before it is complete. (Not to mention the research, after reading Bill's site, my head is spinning....)

Anyway, from what I read people tend to agree that fine dust under 1 micron is the true danger. However, with all of the popular ambient air filtration units out there, there doesn't seem to be any that address or offer filtration at that level. (at least not at the "hobbyist" or under $2k level) So for the not so wealthy people like myself who want to protect our lungs including a good cyclone system what do we do?

Is it possible to find a hepa filter that will fit into an existing, name brand unit, or are we stuck making our own. I know it is usually less expensive to make our own, but I don't want to spend a year building all my own safety equipment (Cyclone, air filter, downdraft stations, etc) before even starting the actual wood working projects. It would be nice to buy a $300 name brand unit and fit hepa filters.

That is my first priority to sort through, then it looks like a few other good points were brought up as well. When do you run the air filters? How about the performance difference between ceiling mounted and floor units.

David, I will try contacting people at Wynn, thanks. I'm surprised with all the wonderful work Bill Pentz has done with cyclone design that he didn't design a great air filtration unit to go with it...hmm just a thought, I'm sure he is busy though, I think He mentioned helping out his son with the business.

Sorry to be so long winded I'm off to check out the fine woodworking article. Thanks Van.


Ed

[Rod Nikkel]

Generally speaking though, your 1 micron rated filter captures 97+% of all particles 1 micron and larger, they also typically capture somewhere in the high 80% range of particles .3 to 1 microns...

Not really. It will capture 97+% by weight, but not particle numbers, right off the bat. That means that, according to this graph on the Wynn site itself, http://www.wynnenv.com/filter_efficiency.htm less that 1/2 the 1 micron dust gets caught and less than 1/3rd of the .3 micron dust is trapped. Most goes right through till the filters have enough dust in them that the dust cake makes them more efficient at trapping particles, but less efficient at letting the air through. Here's what a few hours of research, including talking to the technical people at the filter companies, taught me. http://www.sawmillcreek.org/showthread.php?152117-Filter-Ratings-what-they-mean-(and-don-t-mean) If you really want to start off with clean air through the filters, you have to go at least MERV 16.

[phil harold]

Bill Pentz recommends exhausting the cyclone to the outside
this will eliminate the fines being recirculated in the structure

[Rod Nikkel]

Phil,
That really is the ideal way to go. But when we started working this morning it was -27C (about -15F) and our Clear Vue set up will totally replace the air in our shop in less than 3 minutes. You just can't heat replacement air fast enough to keep from freezing everything in the shop in the winter! So spring, summer and fall we vent outside. In the winter, we have to filter, which is why I did the research as to why our brand new, highly rated filters were reading over 12,000 on the Dylos air meter. It was "interesting" what I found out, and that is what I want other to know. Just because it says 97% does not mean 97% of the particles right off the bat. A lot of that fine stuff goes through for a while, so you still need to wear your masks.

[David Hostetler]

Let me sum up what I was trying to say in my initial post. No there isn't a way to fit "HEPA" filters into an existing ambient air fliter. Mostly because the "HEPA" filter rating is most often applied to vacuum cleaners, and not room or building air filters. Room or building air filters are typically rated in MERV ratings. And while a filter may be rated at "1 micron" efficiency, it may have a MERV rating of 15, whereas a competing filter with a ".5 micron" rating will have a MERV rating of 13 . With the MERV ratings, the larger the number, the better the efficiency... I believe the 3M Filtrete Ultimate Allergen filtes are MERV 15, as is the Wynn Environmental spun bond poly filter media. But at micron ratings they are at 1 micron... I am not sure how that all works. I would suggest calling Wynn Environmental and asking Dick Wynn himself. He explained it once to me and it made sense then... Also Bill Pentz HIGHLY recommends the Spun Bond poly filtration media... Which is what ClearVue used, and the Wynn 35A filter on my cheapo HF DC uses... (And the PSI primary filter on my ambient filter uses...). Long story short, after all the Pentz reading I have done, I am comfortable that I am filtering sufficiently, I am NOT super comfortable with the duct sizing I am using, but I am not overly concerned about it. On my short list of items to pick up is a Dylos meter though. It might make me want to upgrade my DC, who knows?

[Frank Martin]

I have an Oneida cyclone, a ceiling mounted Jet air filter and wear this http://www.envirosafetyproducts.com/3m-clearvisor-adflo-system-papr-respirator.html in the shop. Very comfortable and the best thing I got for the shop...

[phil harold]

Rod
I understand the cold air return issue all too well

The OP is looking for ".3 micron Hepa Filters" for his basement shop
I will assume that he is not worried about just his lungs and is trying to keep dust from migrating into the rest of the house and his family.

To get good filtration, the air needs to be run thru multiple filters, expecting the canisters on your cyclone to do this is unrealistic

For a round a 1000 bucks Honeywell makes a 3 micron Hepa filter it only will do at the max 400cfm. I am sure if you don’t filter sawdust before it gets to this unit it will fail pretty fast.

His best chance is to but the cyclone and canisters in a sealed room with bank multiple filters in the wall for the air to return. There is still the problem of changing and cleaning filters and dust not reaching the cyclone at the creation point

The best solution is just to get the contaminated air out of the building before it gets in ones lungs

There are air exchangers that can reduce the heat loss
But in reality multiple filters and of the returned air from the cyclone and a continuous run ambient air filter will reduce the particles.

.3 micron Hepa Filters are used in the medical industry all the time, they just get expensive

[mreza Salav]

My suggestion is to build your own unit. It has many advantages to the commercial ones:
1- You can put a lot more filter area than the commercial ones, mine has two layers of 16"x25" filter on each side (two sides)
2- You can get the best filters you can find out there for furnace and a lot cheaper than the commercial air cleaner units
3- It's cheaper to build and if you use an old furnace fan it will have more CFM than most commercial units.

Here is one I built, since then I have added another layer of filter on the outside;
http://www.sawmillcreek.org/showthread.php?103512-Home-made-air-cleaner&highlight=
I put cheaper filters on the outside that I replace/clean more frequently than the more expensive and better behind them.

[phil harold]

1- You can put a lot more filter area than the commercial ones, mine has two layers of 16"x25" filter on each side (two sides)
2- You can get the best filters you can find out there for furnace and a lot cheaper than the commercial air cleaner units
3- It's cheaper to build and if you use an old furnace fan it will have more CFM than most commercial units.
I put cheaper filters on the outside that I replace/clean more frequently than the more expensive and better behind them.

Good points but are we getting down to .3 microns?

[David Hostetler]

Rod
I understand the cold air return issue all too well

The OP is looking for ".3 micron Hepa Filters" for his basement shop
I will assume that he is not worried about just his lungs and is trying to keep dust from migrating into the rest of the house and his family.

To get good filtration, the air needs to be run thru multiple filters, expecting the canisters on your cyclone to do this is unrealistic

For a round a 1000 bucks Honeywell makes a 3 micron Hepa filter it only will do at the max 400cfm. I am sure if you don’t filter sawdust before it gets to this unit it will fail pretty fast.

His best chance is to but the cyclone and canisters in a sealed room with bank multiple filters in the wall for the air to return. There is still the problem of changing and cleaning filters and dust not reaching the cyclone at the creation point

The best solution is just to get the contaminated air out of the building before it gets in ones lungs

There are air exchangers that can reduce the heat loss
But in reality multiple filters and of the returned air from the cyclone and a continuous run ambient air filter will reduce the particles.

.3 micron Hepa Filters are used in the medical industry all the time, they just get expensive

A separate enclosed room with filtered air return for the cyclone is a great idea, and one a lot of guys do, this will not only reduce any blown by dust from the cyclone filters, but also reduce the noise level...

And you are right, that doesn't address the fines that are missed at the point of origin. That is where improving the dust hoods on all of the machines comes into play. But even with the best dust hoods, there WILL be fines in the air. Which is where the ambient air filters come into play... Even with 80% + filtration efficiency with each pass through the filter, and frequent exchanges of air through the filter media, I would think, perhaps incorrectly that the fines that get missed have exponentially increasing chances for capture on each pass... Simply put, capture the dust at the source as much as you can, get the best filters you can, duct your system as efficiently as you can, and use at the minimum a 1 micron filter in your ambient filter. If you want better filtration, build your own ambient filter and use MERV 15 filter as your final filtration stage. See my previous post on the confusing nature of filtration ratings. I can only wish you luck on building your own though. I have low ceilings, and the smaller squirrel cage blowers are a rare find around here. I found 3, 2 that were so badly bent up when the contractor yanked them as to be unserviceable, and 1 that the motor was rusted up on it and it wouldn't move. I should have kept one of the bent ones for the motor come to think of it.... Anyway, it seems squirrel cage blower availability varies by region... If you build your own, you will have to come up with some way to control the machine, unlike commercially available units where remote control, and timers are already figured out for you...

Blowing fines outside is fine, if you live in an unusually temperate climate, but for those that live in the bone chilling north, or the searing south, that is just not a good option. Blowing your conditioned air outside would make a shop a miserable place to be very quickly...

If even that isn't enough to satisfy you on protecting your family, get that shop OUT of your basement and in to a separate, dedicated shop building.

[phil harold]

If even that isn't enough to satisfy you on protecting your family, get that shop OUT of your basement and in to a separate, dedicated shop building.

+1
ka-ching

[mreza Salav]

Good points but are we getting down to .3 microns?

I said I have cheaper filters on the outside and better (and more expensive) filters behind them (second layer).
You can get HEPA filters if you wish all the way but I find it more cost saving to replace the cheaper filters more often than the more expensive ones.

I have used air quality monitors (down to 0.5 micron particles) to check air quality in the house and in the shop (which is in the basement).
In a typical day (months after doing any woodworking in the shop) the quality of air in the shop and the rest of the house is the same. In fact house is a bit worse because of
more traffic, etc. With the air cleaner running I get much better numbers even after moderate amount of wood working in the shop. So I am fairly confident my shop is not affecting the air
quality of the rest of the house as far as I can measure.

[Rod Nikkel]

On my short list of items to pick up is a Dylos meter though.

You sure learn things when you have one of those! Recommended for anyone who is concerned about dust.

[ed mendenhall]

I have an Oneida cyclone, a ceiling mounted Jet air filter and wear this http://www.envirosafetyproducts.com/3m-clearvisor-adflo-system-papr-respirator.html in the shop. Very comfortable and the best thing I got for the shop...

Frank, that looks like a nice unit. A little pricey though, if i had the capital I would go that route and not be so worried about the air filtration.

[ed mendenhall]

As I design the shop, let's assume I have a good cyclone set up, cyclone is in separate room with filters in the wall, I am venting outside when weather permits, and my collection at the source is good (with upgraded/modified ports).

The next step is to catch any residual dust in the air. From what I am reading .3 micron capture is recommended, yet these units/filters don't seem to be available. Are we left with no choice but to try to design and make our own. Is 1 micron good enough if we have a first class cyclone setup? I wonder what Bill Pentz does in his shop (if anything) to compliment his cyclone?

I would rather overkill with machinery and not have to rely so much on the respirator while in the shop.

Ed

[ed mendenhall]

Hi Mreza, Your design looks great. If I have to build my own I will look to your design. Were you able to get .3 micron filters for your inner filters?

[David Hostetler]

I wonder what Bill Pentz does in his shop (if anything) to compliment his cyclone?

I would rather overkill with machinery and not have to rely so much on the respirator while in the shop.

Ed

Has anyone thought to ask him?

From what he publishes on his site at http://billpentz.com/woodworking/cyclone/docsorders.cfm#AirFiltering it appears that he is pretty much up in the air about post collection filtering, he mentions the 1 micron ambient filters as being useful, but not something to rely on fully...

HIS recommendation at least on this page is to blow the fines from your dust collector outdoors, replace your shop vac filter with a HEPA filter, and post filter with a 1 micron filter like the Jet AFS1000

From Bill Pentz site where he discusses cartridge filter conversion for single stage dust collectors he says...
"Replacing the original bags with a top quality cartridge filter from the various hobbyist vendors made for these conversions works, but all of the existing conversion cartridges and new hobbyist units are only offering 2-micron or worse filtering. With the worst health damage caused by 2.5-micron and smaller sized particles, these don’t offer much protection. That’s why I recommend using certified 0.5-micron or better yet 0.2-micron cartridge filters. With my support Wynn Environmental developed a new 0.5-micron wide pleated filter designed to mount right on most 1.5 hp to 2 hp dust collectors. They make this filter in the same paper poly blend that most other makers offer, and offer it in the far superior all poly version." (Source http://billpentz.com/woodworking/cyclone/DCConversion.cfm#LesserSolutions)
I mention this just to illustrate that there is some info there that is making Bill recommend the poly blend filter, even though it shows up on the web site as 1 micron rated, and the MERV rating I have seen at 15 (~ .3 micron filtration) is as close to HEPA as I am going to get for a hobby wood shop dust collector. KNOWING this, I would say that a good MERV 15 furnace type filter would give you the filtration you want. This would most easily be done with an ambient filter that is shop built... You MAY be able to adapt an over the counter say Filtrete Ultimate Allergen filter to a production filter unit, I do not know... But I don't get he feeling from what I see in Bill's writings that at this point, it is a worthwhile excersize... I could be wrong.

[ed mendenhall]

Has anyone thought to ask him?

From what he publishes on his site at http://billpentz.com/woodworking/cyclone/docsorders.cfm#AirFiltering it appears that he is pretty much up in the air about post collection filtering, he mentions the 1 micron ambient filters as being useful, but not something to rely on fully...

HIS recommendation at least on this page is to blow the fines from your dust collector outdoors, replace your shop vac filter with a HEPA filter, and post filter with a 1 micron filter like the Jet AFS1000

From Bill Pentz site where he discusses cartridge filter conversion for single stage dust collectors he says...
"Replacing the original bags with a top quality cartridge filter from the various hobbyist vendors made for these conversions works, but all of the existing conversion cartridges and new hobbyist units are only offering 2-micron or worse filtering. With the worst health damage caused by 2.5-micron and smaller sized particles, these don’t offer much protection. That’s why I recommend using certified 0.5-micron or better yet 0.2-micron cartridge filters. With my support Wynn Environmental developed a new 0.5-micron wide pleated filter designed to mount right on most 1.5 hp to 2 hp dust collectors. They make this filter in the same paper poly blend that most other makers offer, and offer it in the far superior all poly version." (Source http://billpentz.com/woodworking/cyclone/DCConversion.cfm#LesserSolutions)
I mention this just to illustrate that there is some info there that is making Bill recommend the poly blend filter, even though it shows up on the web site as 1 micron rated, and the MERV rating I have seen at 15 (~ .3 micron filtration) is as close to HEPA as I am going to get for a hobby wood shop dust collector. KNOWING this, I would say that a good MERV 15 furnace type filter would give you the filtration you want. This would most easily be done with an ambient filter that is shop built... You MAY be able to adapt an over the counter say Filtrete Ultimate Allergen filter to a production filter unit, I do not know... But I don't get he feeling from what I see in Bill's writings that at this point, it is a worthwhile excersize... I could be wrong.


Thanks David, Maybe I'll try contacting Bill through his site. Sounds like if the cyclone is set up correctly to begin with, I shouldn't be overly concerned with the ambient unit using true hepa filters. Shoot for 15 or 16 merv.....

[mreza Salav]

Hi Mreza, Your design looks great. If I have to build my own I will look to your design. Were you able to get .3 micron filters for your inner filters?

Thanks. I should add those photos are before adding the second layer. I've just added two rubber bands (on each side) that run from the top to bottom
and the outer filters slip under them (and over the inner filters). This way it's very easy to change them.
I don't use HEPA rated, just the best filters available in typical BORG's (3m Filtrete's).

You can get really good filters though with MERV rating of 16. Here is one for example:
http://www.amazon.com/AirTamer-Ultra-Performance-Pleated-Filter/dp/B002B55X1I/ref=pd_bxgy_hpc_img_b

[david brum]

You can get replacement filter for common woodshop ambient air filters from Wynn. The Wynn filters are rated MERV 14, designed to capture 75-85% of .3-1.0 micron particles.
http://www.wynnenv.com/jet_filters.htm

[phil harold]

The next step is to catch any residual dust in the air. From what I am reading .3 micron capture is recommended, yet these units/filters don't seem to be available. Are we left with no choice but to try to design and make our own.

Ed
Honeywell makes one, f500, that filters at 99.97% (at 0.3 microns) but I would filter air before it reaches this unit
http://www.amazon.com/Honeywell-F500A1000-Whole-House-Cleaner/dp/B000X1DKT4

replacement filters are 150 bucks for the hepa one


has any thought about installing an electrostatic unit in their home built ambient air filter?

http://www.electro-breeze-supply.com/electrostatic_air_filters.html

[ed mendenhall]

thanks for the link


Thanks. I should add those photos are before adding the second layer. I've just added two rubber bands (on each side) that run from the top to bottom
and the outer filters slip under them (and over the inner filters). This way it's very easy to change them.
I don't use HEPA rated, just the best filters available in typical BORG's (3m Filtrete's).

You can get really good filters though with MERV rating of 16. Here is one for example:
http://www.amazon.com/AirTamer-Ultra-Performance-Pleated-Filter/dp/B002B55X1I/ref=pd_bxgy_hpc_img_b

[ed mendenhall]

Honeywell makes one, f500, that filters at 99.97% (at 0.3 microns) but I would filter air before it reaches this unit
http://www.amazon.com/Honeywell-F500A1000-Whole-House-Cleaner/dp/B000X1DKT4

replacement filters are 150 bucks for the hepa one


has any thought about installing an electrostatic unit in their home built ambient air filter?

http://www.electro-breeze-supply.com/electrostatic_air_filters.html


those look like interesting units, particularly the electro breeze. Maybe I should go with Jet, etc with 1 micron and add one of those whole house hepa units to my ac ducts.

Maybe I'm over thinking this whole thing. I never gave it a thought until I came across Bill Pentz's site and all the forum discussions. (glad I did though)

any opinions on this unit??? http://grizzly.com/products/G0573

[David Hostetler]

Thanks David, Maybe I'll try contacting Bill through his site. Sounds like if the cyclone is set up correctly to begin with, I shouldn't be overly concerned with the ambient unit using true hepa filters. Shoot for 15 or 16 merv.....

I think you've got the right idea... FWIW, you asked about the G0573, I have the G0572, and honestly wish the filters had the same MERV ratings as the G0573. My main issues with the issue you pointed out are size, and air flow. The low speed CFM is just a bit lower than my highest, and that is a LOT of air movement...

[Frank Martin]

Frank, that looks like a nice unit. A little pricey though, if i had the capital I would go that route and not be so worried about the air filtration.

Totally understand Ed. I have pollen allergies and have a family history of other allergies. So, you can say I am more likely to develop problems with dust than others... And I really want to continue woodworking. For this reason, I did not mind paying for it and wish I had gotton one years ago...
Good luck with your search...

[ed mendenhall]

Do you think that much air flow would be detrimental? (my entire basement is about 1,200 sq/ft with 2/3 for the shop) Is it a bad trade off for the .3 micron filter? I also assume it will be loud.

I know more the cfm the better with cyclones, is that different with ambient filters?

Thanks again


I think you've got the right idea... FWIW, you asked about the G0573, I have the G0572, and honestly wish the filters had the same MERV ratings as the G0573. My main issues with the issue you pointed out are size, and air flow. The low speed CFM is just a bit lower than my highest, and that is a LOT of air movement...

[michael dilday]

I have a 18x22 shop with a Jet AFS-1000B filter with the Wynn internal filter and a Home Depot outer filter. I also have a Jet JCDC-3 dust collector. I also have a Dylos air quality monitor that measures down to .3 microns. When I pollute the air with small particles there Jet air filter removes them down to a safe level in about 10 minutes. I can tell you from experience that the Jet air filter works. Collecting at the machine is not 100% even if you have a great dust collection system. Shaving a piece on the table saw will really spit out a lot of small particles. Small particles stay in the air for a very long time.

[Rod Sheridan]

Ed, I have a cyclone with a HEPA filter, the shop air is cleaner with it running than outdoor air, or any other room in my house.

Since the really small particles aren’t separated by the cyclone, they are captured by the filter, it shouldn’t matter what device you use them on as long as it is fairly leak free.

Regards, Rod

[Ole Anderson]

I strap a Filtrete Ultimate filter onto a box fan, set it next to where I am working, and work away.
This is in addition to my DC system (Oneida).
I used to do that until I realized that a box fan simply doesn't have the chops to deal with the pressure loss across anything other than a cheap furnace filter. Yea, it sorta of works. You might be pushing a couple of hundred cfm, vs 1000 cfm with an ambient air cleaner with a squirrel cage fan. If you really need a budget solution, start with an old furnace blower. That could accommodate a prefilter and a HEPA filter.

[Ron Selzer]

I mounted a used furnace fan under my homemade bench. completely closed and sealed off one half of the bench underneath. then cut 24x24" openings in both sides.Installed 24"x24" bag filters with 24"x24"x4" prefilters. Have changed the prefilters a couple of times have not changed the bag filters yet. Have a magnehelic monitoring the pressure drop and it has yet to rise enough to change the bag filters. Turn it o when I go down in the basement to work and turn it off days later. Wife comes down and says she can't smell anything and her allergies don't flair up as long as I do this. If I cut on table or radial arm saw, use the router, sander or wide belt sander without doing this she can tell even if she is not in the house when i do and comes home later. I have a cyclone with 3hp and 2 hp dust collectors that automatically come on when using any stationary tool. A shop vac with cyclone hard piped for use with hand power tools and the over blade guard on table saw.