MERV 16 (or HEPA) Air Scrubber/ Filtration

[Peter Aeschliman]

Now that is awesome. I already have two big Wynn Environmental filters that won't have a purpose for after I start venting my DC outside. I was wondering what I was going to do with them. This might be the ticket, and it will involve far less work to build.

I also like that the air flow isn't as direct on the inlet side with a round filter. With two of these suckers, and maybe a few well-placed fans in the shop to direct the air toward them, I might be in luck.

Thanks for pointing that out, Jery! I've spent a lot of time on Bill Pentz's site, but I didn't see that.

[Phil Thien]

Now that is awesome. I already have two big Wynn Environmental filters that won't have a purpose for after I start venting my DC outside. I was wondering what I was going to do with them. This might be the ticket, and it will involve far less work to build.

Just make sure the airflow wouldn't reverse in the new application.

You don't want the blower pulling from the dirty side.

[Peter Aeschliman]

Yeah, good point. I was thinking about that- currently the dust accumulates on the inside of the filters as configured on my DC. If I go Bill's route and pull the air through the filter, I'll be sucking the dust from the previous setup out of the filter and into the shop... So I'll have to push the air into the filters I guess. Or wash the filters out really well... I bought the washable kind.

[David Kumm]

Filters are made to filter either from outside in or inside out and can't necessarily be reversed so find that out. Cartridge filters were originally designed as outside in and it is only recently that companies have used them inside out. Even if designed that way they aren't as easily cleaned. The dylos will really give you great info as to air quality and to some extent change the way you think about MERV ratings and airflow. They also give you an excuse to never sweep the floor. Those numbers are scary. Dave

[Steve Milito]

Hi guys,

I'm trying to improve the quality of the air in my shop. I've noticed that I get a sort of tightness in my chest just behind/below my sternum after a day of working in my shop. I have a plan for upgrading my dust collection, so now I'm turning my attention to air filtration.

Maybe what you really need is a stress test . . .

[Peter Aeschliman]

You mean a cardio stress test, or a test of emotional stress?? ;-) My cholesterol and blood pressure are all normal, so I'm confident it's related to wood dust.

The tightness I refer to only lasts for 4-5 hours after I'm in the shop... accompanied with very slight shortness of breath. The signs are pretty minor at this point, but I do notice them. They got particularly bad after I tried using some new plastic bags on my DC that were over-sized. I've been using them for about a month and a half. They leak like crazy, and every time I run the DC I start to feel it. Hence this round of changes.

It made me realize that I won't be doing this hobby for much longer if i don't think long term and get my air quality sorted out. I'm only 32 years old, and I want to keep doing this hobby until I'm pushing around a walker! ;-)

[Peter Aeschliman]

Filters are made to filter either from outside in or inside out and can't necessarily be reversed so find that out. Cartridge filters were originally designed as outside in and it is only recently that companies have used them inside out. Even if designed that way they aren't as easily cleaned. The dylos will really give you great info as to air quality and to some extent change the way you think about MERV ratings and airflow. They also give you an excuse to never sweep the floor. Those numbers are scary. Dave

Good to know. I'll just assume the flow direction needs to go inside out, since that's what Wynn designed them for. Right now I'm also glad that I sprung for the washable filters.

[ian maybury]

I'd not noticed Bill's piece on using a cartridge filter as an air cleaner. It's a nice set up - minimal space is taken up. Depending on what the numbers look like you could consider running two cartridges stacked on top of each other to minimise pressure drop and slow the build up of dust.

One advantage if you can find suitable filters and run the airflow from the inside to the outside of the filter is that it would be about as effective a diffuser as you can imagine. Presuming a decent fan you'll get a strong draught if you exhaust the fan through say an elbow.

The in line fan is a neat idea too, but axial flow fans don't make much by way of pressure compared to say a BC radial as used on dust systems, so it'd be worth digging out filter manufacturer's data to make sure that the pressure drop the filters will deliver in use (including when a bit dirty) will be comfortable within the pressure capability of the fan...

ian

[michael osadchuk]

You mean a cardio stress test, or a test of emotional stress?? ;-) My cholesterol and blood pressure are all normal, so I'm confident it's related to wood dust.

The tightness I refer to only lasts for 4-5 hours after I'm in the shop... accompanied with very slight shortness of breath. The signs are pretty minor at this point, but I do notice them. They got particularly bad after I tried using some new plastic bags on my DC that were over-sized. I've been using them for about a month and a half. They leak like crazy, and every time I run the DC I start to feel it. Hence this round of changes.

It made me realize that I won't be doing this hobby for much longer if i don't think long term and get my air quality sorted out. I'm only 32 years old, and I want to keep doing this hobby until I'm pushing around a walker! ;-)

Peter,

I'm not a doctor..... but it sounds from the above that your immune system has been comprised.....

the bad news is, of course, if this is the case, that it could get worse if you don't track down what is attacking it and deal with the 'triggers'; you may have to give up or significantly modify activities you enjoy like woodworking....

the good news is that you can recover some or most of the losses to your immune system, etc.

ironically, another small piece of the good news is that given that your body appears to be 'sensitized' to the triggers that are affecting your breathing, to an extent your body can act as a dust particle counter/monitor ........ you already seem to know some of the triggers in the workshop (eg. breathing immediately affected when turning on DC with the oversized/leaking plastic bags).......
... this is the opposite of many self reports where people say "I don't see any dust in the air and my body isn't being discomforted at the moment and conclude the air quality in their workshop must be fine" just like people attending a lot of rock concerts/use headphones at too loud a setting and say their hearing is fine (hearing loss has not yet become subjectively apparent)......

..... if you make one change at a time in your workshop dust collection/air filtration and workshop activities, the signals your body is giving off may be sufficient to guide you in improveing the air quality in your workshop

I've had a Dylos particle counter (the cheapest, base model calibrated for 1/5 microns) now for 5 years and have used it to track down problems with dust collection or when I do something new in the shop that might generate excessive dust particles.... otherwise I no longer use it continuously when I'm in the shop because I've come to know, with the dust collection setup I now have and with routine shop work activity, I won't have an air quality problem

good luck

michael

[Peter Aeschliman]

Ian, you raise good points.

On the one hand, I like the idea of the filter acting as a diffuser (won't stir up as much dust), but on the other hand I worry that it won't adequately contribute to the circular air flow I need in the shop. That could be solved by adding some hanging fans in strategic locations I suppose... but then we circle back to the concern about stirring up dust. I tend to think that if I'm doing a good job of collecting dust at the source, and collecting dust that escapes my DC via air filtration, there shouldn't be much dust left over to stir up. So I want to approach the "dust stirring" issue by solving the root cause, which is, don't let the dust settle in the first place- capture it!. So long story short, I've talked myself into wanting that circular air flow in the shop, which means that I'll need to overcome the diffuser effect by via additional fans.

As for the pressure drop, this is definitely a concern. Interestingly, one of the fans I saw while looking around actually comes with a cartridge style filter attachment:

http://www.amazon.com/247Garden-Inli...%22+inline+fan

Amazon doesn't provide much detail on the filter, but it's way smaller than my Wynn filters. I'm not sure how it would compare to my Wynn filters in terms of static pressure impact, but if I were a betting man, I would assume my Wynn filters will do a better job due to their size.

The good news is that the expensive part of this is already done- the filters. This fan is pretty inexpensive, so I'm tempted to just take the risk on Bill Pentz's recommendation:

http://www.amazon.com/inch-inline-hi...%22+inline+fan

[Peter Aeschliman]

Peter,

I'm not a doctor..... but it sounds from the above that your immune system has been comprised.....

the bad news is, of course, if this is the case, that it could get worse if you don't track down what is attacking it and deal with the 'triggers'; you may have to give up or significantly modify activities you enjoy like woodworking....

the good news is that you can recover some or most of the losses to your immune system, etc.

ironically, another small piece of the good news is that given that your body appears to be 'sensitized' to the triggers that are affecting your breathing, to an extent your body can act as a dust particle counter/monitor ........ you already seem to know some of the triggers in the workshop (eg. breathing immediately affected when turning on DC with the oversized/leaking plastic bags).......
... this is the opposite of many self reports where people say "I don't see any dust in the air and my body isn't being discomforted at the moment and conclude the air quality in their workshop must be fine" just like people attending a lot of rock concerts/use headphones at too loud a setting and say their hearing is fine (hearing loss has not yet become subjectively apparent)......

..... if you make one change at a time in your workshop dust collection/air filtration and workshop activities, the signals your body is giving off may be sufficient to guide you in improveing the air quality in your workshop

I've had a Dylos particle counter (the cheapest, base model calibrated for 1/5 microns) now for 5 years and have used it to track down problems with dust collection or when I do something new in the shop that might generate excessive dust particles.... otherwise I no longer use it continuously when I'm in the shop because I've come to know, with the dust collection setup I now have and with routine shop work activity, I won't have an air quality problem

good luck

michael

Hi Michael- I think you and I were posting at the same time.

I hear you, and I really appreciate your concern. These symptoms are only very recent. I've been working with Black Walnut almost exclusively over the last few years. The first time I cut into the stuff, it bothered my respiratory system. Nothing extreme, just obnoxious. Much worse than the Cherry and Maple I was accustomed to. What I haven't said is that I've also dabbled in metalworking recently. At one point a few weeks ago, after using my angle grinder on some steel, I noticed my lungs were really irritated. There was somewhat of a cloud of grinder dust in the air. I actually had to leave the shop and let my air scrubber work for a few hours. I also have a sandblasting cabinet that is ventilated using my shop vac. I use aluminum oxide media. I wear my respirator while I do that, so it hasn't really bothered me.

Over the last month or two, my lungs have been a bit more sensitive. Again, nothing extreme here. I'm just trying to pay attention to what my body is telling me.

I think I might be communicating my symptoms in this thread in such a way that it's coming across as far more extreme than it is. But frankly, it's the catalyst for my dust collection/air quality projects. So it is significant enough for me to take action.

Of course I hope I haven't permanently screwed up my respiratory system. Whether my symptoms are temporary or permanent, I need to take action. I just hope I haven't taken action late enough that I have to walk away from woodworking altogether (I highly doubt that though).

[Michael W. Clark]

So long story short, I've talked myself into wanting that circular air flow in the shop, which means that I'll need to overcome the diffuser effect by via additional fans.

As for the pressure drop, this is definitely a concern. Interestingly, one of the fans I saw while looking around actually comes with a cartridge style filter attachment:

http://www.amazon.com/247Garden-Inli...%22+inline+fan

Hi Peter,
I know you are concerned about direction of flow through the cartridge filter, but I think if you clean your filter adequatly, you could reverse the flow without any issues. This being said, you could put the cartridge filter on the inlet of an axial fan as shown in the BP link, then discarge through a straight piece of duct. This would give you the most filter area in the smallest space and still promote your air currents. I just looked at the picture in the BP link and didn't read the text, this may be what he is suggesting.

The carbon filter in your filter fan link, will not be good for your intended purpose. The carbon filter is for odor control and will plug with significant particulate levels, thus limiting airflow and your circulation effect.

If you are going to build the air scrubber box arrangement, look for envelope style filters with the media/filtration requirements you want. The envelope style will give you more filter area. You can include a framework inside your box to increase the number of filters if you desire, but there are a lot of sizes commercially available. You may have to go to a commercial/industrial filter manufacturer for more choices. The prices should be competitive. A regular furnace filter will work for the intake or a register grill. The furnace filters will reduce the loading on the more expensive envelope filters, but it may be minimal depending on your dust size. The register grill would at least act as a safety guard over the fan intake.

Mike

[Peter Aeschliman]

Hi Peter,
I know you are concerned about direction of flow through the cartridge filter, but I think if you clean your filter adequatly, you could reverse the flow without any issues. This being said, you could put the cartridge filter on the inlet of an axial fan as shown in the BP link, then discarge through a straight piece of duct. This would give you the most filter area in the smallest space and still promote your air currents. I just looked at the picture in the BP link and didn't read the text, this may be what he is suggesting.

The carbon filter in your filter fan link, will not be good for your intended purpose. The carbon filter is for odor control and will plug with significant particulate levels, thus limiting airflow and your circulation effect.

If you are going to build the air scrubber box arrangement, look for envelope style filters with the media/filtration requirements you want. The envelope style will give you more filter area. You can include a framework inside your box to increase the number of filters if you desire, but there are a lot of sizes commercially available. You may have to go to a commercial/industrial filter manufacturer for more choices. The prices should be competitive. A regular furnace filter will work for the intake or a register grill. The furnace filters will reduce the loading on the more expensive envelope filters, but it may be minimal depending on your dust size. The register grill would at least act as a safety guard over the fan intake.

Mike

Thanks Michael- I'll call Wynn and ask about the flow direction. I definitely would prefer to pull air through the filter (outside in) for air circulation reasons. After cleaning the filters (compressed air, then water), I could always run them for a few hours outside to get anything left over.

As for the carbon filter in the link- yeah, I definitely wasn't thinking about using that for my application. I just thought it was a clue that a these fans can work with filters without burning out or having the airflow hurt too badly. But I won't know until I try it with my Wynn filters.

I'm pretty much decided at this point that I'm going to go the BP route since I already have the filters on hand. It will save me money and time, and hopefully yield the same results. Plus, I can also buy the upgraded filters for my jet unit and have three air scrubbers in the shop. Can't hurt!

[Peter Aeschliman]

I just spent about 2 hours cleaning out my Wynn filters. I'm shocked by how much dust was in them. I've cleaned them a few times over the last 3 years with compressed air... But wow. I went pleat by pleat washing them with water. It took a long time to get the water running somewhat clear.

Needless to say, I won't be reversing the air flow direction after all. I'll need to blow through the filters (inside out)... otherwise I'll be stirring up more dust than I'm catching!

I must have installed my thien baffles incorrectly because it really is amazing how much dust got through. I should probably blame my drum sander.

[Phil Thien]

I must have installed my thien baffles incorrectly because it really is amazing how much dust got through. I should probably blame my drum sander.

Drum sanders are a challenge, even for conventional cyclones.