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

[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/...espirator.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/showthre...ner&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/...espirator.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/cyc...m#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/cyc...esserSolutions)
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/cyc...m#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/cyc...esserSolutions)
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.....