tim wrote:
"Noon-Air" wrote in
:

"gs" wrote in message
...

Extensive snip here

FWIW, a *true* HEPA filter in a resi setting is a waste of
money....True HEPA filters get used in clean rooms and such.
THey are 95%+ efficient....in a resi setting, your gonna get a
whole lot more dust and dirt than a HEPA filter can handle just
by infiltration of outside air, and the system has to be
specially designed for HEPA filters.

I have to disagree just a little bit. My ex had a hard time
sleeping, especially during the fall and winter. She was always
waking up with a sore throat and bleary eyes. I bought a Sears
room-size HEPA filter and it really helped a lot. It even
disappeared the dust bunnies under the bed. The only drawback was
the filters. It would take a new one every couple of months, and
those suckers cost over $25 a piece (probably $50 by now). About a
year later I happened to run across the high-efficiency furnace
filters on sale at my local big box store and tried one. Man, did
that make a difference! The whole house had almost no dust, and
the HEPA filter in the bedroom unit would last for six months or
more. I did the same at my mom's house after I moved in to take
care of her after Dad died. I am sold!

Keep in mind, high efficiency is collection efficiency, not energy
efficiency. All furnaces should have indicators, or warnings for
too restrictive air flow., Some furnaces with variable speed can also
partly compensate for different filters.

greg