Q: Electrostatics

Hi. I have this old 1981 H&R General Electric 15kV/1mA DC supply. It works like a charm, although I have no idea what it came out of. But I've been thinking of using it for electrostatic air filtration.

In the furnace return-air duct, I'd like to open up a section and slide in a well-insulated and grounded "module" consisting of a series of positively-charged collection plates (parallel to the flow of air) and a negative ion supply "grid" ahead of this to emit ions. Of course the plates are easily removable for cleaning.

Yes they make electrostatic furnace filters commercially, but damn are they expensive!

Questions, hopefully someone can help:

1. Is 15kV too high an EMF? Most tabletop ionic devices seem to operate around 7kV/10uA but a furnace duct would have a much larger air volume and velocity.
2. Would the distance between emitter and collector matter much in a forced-air system?
3. Is there a way to calculate the length and diameter of "grid" needed to facilitate ionic production vs. ozone production?
4. Is there a way to calculate optimum collection plate dimensions and surface area?

Or will this all need to be trial-and-error... I don't fancy the notion of patching a gaping hole in the furnace ductwork if the prototype flops. :)

TIA.