On 2/11/2012 5:17 AM, Robert Macy wrote:
On Feb 10, 2:41 pm, wrote:
...snip...
Now, back to the question that I started in another thread.
There is a technology that uses an electric field that does not require
external power.
I thought the field was created by the triboelectric effect of air
passing through insulating media. The only response to that was
the rude statement that, "my education was faulty," but no real
useful help was provided.
The other theory presented was that the electric field was permanently
installed
at the time of manufacture. That was debunked.

I've looked at my sample and can't find any evidence of an electric field.
I stuck one on my HRV, but can't tell if it's better than an ordinary
filter.
That led me to another quest for a particle counter to measure
actual results.
People who sell passive electrostatic filters say they're terrific.
Technical people seem to think they're snake oil.

Jury is still out on that one.

Are we having fun yet?

mike

Yes, term is electrostatic.

Triboelectric is the garranteed charge distribution that is caused by
forcibly separating dissimilar materials with different electron work
functions. Examples are wool to rubber, hair to comb, almost
everything some more than others.

Electrostatic filters REQUIRE air movement to work.

Yes, they work. ...and I'm technical. To be equivalent to electronic
air cleaners requires a bit of volume in comparison.

From memory, I thought it possible/plausible to create a 'built-in'
field during manufacturing, but know that charges would quickly
accumulate to null the fields out. You say it was debunked. Was the
'ability' to "...install..." the charge debunked? Or, rather whether
it was done by electrostatic filter manufacturers at all?

The electronic filter creates several kilovolts across about a
centimeter or so.
I believe you can create a fixed electrostatic field by solidifying a
polar polymer in the presence of a strong electric field.
Since the distance is tiny, you might even convince yourself that you
have similar kilovolts/cm. But does that do any good in a filter
application.
Wouldn't a dust particle have to actually bang into that molecule
to experience any field at all?
So, if the electrostatic had any permanent electric field, where is it
in the material stack and how would one measure it?

I don't have much air volume, so the electrostatic may not work for me
even if it does work in a furnace. Might as well build another
electronic one and be done with it.

A particle counter would settle the question rather easily.
I considered buying one of the $10 Sharp optical counter modules, but
it looks like what I want to measure would be down in the noise level
for that module. The projects built on that module have lots of
glitz, but no real numbers. Anybody can detect a cloud of smoke.
Optically detecting small amounts of pollen is quite another matter.