Not in alt.hvac

I'm guessing this response is a good month late but for what it's
worth...  I would go whole house instead of just the main floor.
Bedrooms are a MUST.  I would also stay away from the HEPA.  The
static pressure would be huge and you are looking at lot of
maintenance over the years as well as increased costs to use the
beefed up blower required.  All for what I consider to be poor
technology!  To give you an example go into any store that sells a
HEPA style air unit(Try Wal*mart the next time you are there).  They
often give you what's referred to as Clean Air Delivery Rate(CADR).
That supposedly tells you how often it will exchange the air in a
given size room.  If you look on the outside of the box you will also
normally see a disclaimer that tells you that the CADR rating isn't
guaranteed past 72 hours of use!  Why not?  Because the air has to
flow through the unit to give you that kind of delivery rate. You
start with a filter media that is real dense to begin with.   Every
particle that is trapped blocks the flow even more.  As time passes
you either need to clean or better -- replace an expensive filter!
Some of the particulate that is stopped can actually grow on the
filter media!  Some particulate is small enough that it will pass
right through the filter media.  All in all, it will work better than
nothing but fairly ineffective and expensive.

The other setup you mentioned I believe would give you much better
results in cutting down air pollution as well as being easier to
maintain!  The electrostatic charges the ir going past and attracts
the particulate to grids normally.  Pull those out regularly, clean
them and put them back in.  The ionization and UV light can kill
viruses that pass right through filter media.  One thing I would do if
possible.  Make sure you have access to the ductwork just beyond the
ionizer and UV light.  Because of how they work you may get some extra
dust there.  I would rather it there than in the air I breathe but
access there would allow you minimize it when you do the maintenance
on the electrostatic filter.  Follow the recommended maintenance
schedules and I believe you will be pleased with that setup!

BTW, I formerly offered air purifiers - mainly room-type -- and in my
opinion just about EVERY home in the US should have SOMETHING even if
it's a HEPA!

Harold Spatz
http://hspatz.healthyhometour.com

Harold Spatz
Healthy Home Tour!
http://hspatz.healthyhometour.com