notbob wrote:

On 2010-08-04, Sam Takoy wrote:

Is this not a commonly available type of filters? Are they not
recommended for some reason? Can someone recommend an (online) place to
purchase them?

HEPA filters are very specialized and have absolutely no place in the
home. Basically, it's become the new marketing scam aimed at rubes.
HEPA filters filter such small particles, they are used in "clean
rooms", where micron sized particles are verboten. You have to build
a specialized room where outside ventilation is strictly controlled
and people wear clean-room bunny suits and the interior air is
constantly recycled through HEPA filtered whole and partial filtering
systems. Even the floors are part of the filtering system. The cost
of these rooms is staggering.

Anything claiming to be HEPA for your HVAC or vacuum cleaner is complete
nonsense.

You do seem to relish being *boldly* ignorant--

Just to keep it easy- here's a copy/paste from Wikipedia-
-start wiki-quote-
"The original HEPA filter was designed in the 1940s and was used in
the Manhattan Project to prevent the spread of airborne radioactive
contaminants. It was commercialized in the 1950s, and the original
term became a registered trademark and a generic term for highly
efficient filters. Over the decades filters have evolved to satisfy
the higher and higher demands for air quality in various high
technology industries, such as aerospace, pharmaceutical processing,
hospitals, health care, nuclear fuels, nuclear power, and electronic
microcircuitry (computer chips).

Today, a HEPA filter rating is applicable to any highly efficient air
filter that can attain the same filter efficiency performance
standards as a minimum and is equivalent to the more recent NIOSH N100
rating for respirator filters. The United States Department of Energy
(DOE) has specific requirements for HEPA filters in DOE regulated
applications. Products that claim to be "HEPA-type", "HEPA-like", or
"99% HEPA" do not satisfy these requirements and may not have been
tested in independent laboratories."
-end wiki-quote-

I'll grant you that Wikipedia is a pretty shake source-- so I welcome
anything other than your opinion on the matter.

Jim


nb