MERV 16 (or HEPA) Air Scrubber/ Filtration

[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.

[David Kumm]

Drum sanders are a challenge, even for conventional cyclones.

Most cyclones are not designed for fine dust. Bags are generally used rather than cartridges due to the inevitable loading. Dave