Electrically enhanced media filtration

[lownox]

I am looking for opinions on this situation. As a product development engineer, often times the success of the project depends greatly on how equipped the lab is. For example, if you don't have a multimeter... you probably would do much electrical work. Anyhow, to my scenario...

Ashrae standard 52.2 relates to filtration with regard to partical size. If a company were trying to develop an electrically enhanced media air cleaner for residential application, is it fair for the engineers to expect to be able to fully test this unit for standard compliance. This standard relates to rating the performace of the filter (MERV), but if an engineer must use old methods and methods that don't apply to this standard... he really doesn't have a good gauge as to what he has constructed.

What it comes down to is we experimenting in this area and the only tests we can run are Ashrae 52.1 dust spot efficiency and a DOP test using a cascade impactor. Keeping in mind that we are using media filtration in this unit, it seems like sending an oil mist down the duct is not appropriate. Sounds remotely reasonable?

I am argueing that we cannot develop such a unit without first equipping ourselves with the tools required to test with. This post may beg for someone that has more experience than I with these standards, but I am hoping maybe someone is lurking who can offer some advice. Thanks.

Steve

 

[MintJulep]

Is there a question?

It sounds as if you don't fully understand the ASHRAE 52.1 and 52.2 test standards. They define methods of test. You perform a test following the method defined by the standard, and the result is a number that you can report. There is no "compliance" of the actual product under test to the standard.

It sounds to me as if you want to say "We have a filter that is so good it can't even be tested by existing methods."

Very typically this is the sales pitch of the snake oil huckster.

 

[lownox]

No snake oil at all. Fact is I think we have a crappy concept going. You are correct I am not savy in the art of filtration design. I am thrown to the proverbial wolves on this project and getting little to no help from management. Also, I know there is no "compliance" with regard to those standards... bad choice of wording.

I know, I know... not your problem. The question is clearly presented in para. 3. Although insinuated.

Is DOP an effective or appropriate aerosol to use for media filter testing? I should have stated it this way initially... sorry. The 52.2 standard suggests potassium chloride as a challenge aerosol, but we are not equipped for that.

I am trying to determine if I have a viable argument that we are not equipped to develop this unit and need to purchase the proper equipment... i.e. testing apparatus like that described in 52.2. We have a duct arrangement as outlined in 52.1, but my argument is that it is not sufficient for developing a unit that is supposed to be about MERV 15 equivalent. The DOP question is the one I really am seeking advice on.

Thanks for your initial reply and anything else you can add.

Steve

 

[MintJulep]

Ok.

Yes, DOP has been used as a filter testing particle. You might want to look at ASTM D 2986 "Standard Practice for Evaluation of Air Assay Media by the Monodisperse DOP (Dioctyl Phthalate) Smoke Test" for a historical perspective. The standard has been withdrawn, without replacement.

MIL-STD-282 might also be of interest.

I'm not sure that DOP could be used in a 52.2 tester to produce a "valid" result. I don't think a DOP smoke generator produces the range of particles needed.

 

[lownox]

Thanks for the info. I have been researching a lot to develop some simple testing methods for my own use. I realize that 52.2 is the standard of choice for what i am doing, but I don't have that type of setup (YET).

I have a cascade impactor and a particle counter.
Operating with the understanding that .3um particles are the most difficult to capture, I am considering "hot" DOP. It seems that cold DOP produces a very few .3um particles vs. larger sizes. I want to minimize the amount of oil deposited on the filters during tests, so i thought "hot" would be the way to go.

Any opinions? Thanks.