On Aug 4, 11:33*am, notbob wrote:
On 2010-08-04, Jim Elbrecht wrote:

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

You've worked how many hours in a true clean room. *You've set up and
designed systems in how many class 1000/100 clean rooms? *Do you know
how big a .3-5 micron particle is? *Do you know how much HEPA
circulation surface/capacity is required for a given volume of space to
achieve ANY level of HEPA classification? *You've certified how many
environments for particulate levels?

Hell, even the first clean room I worked in was a joke. *After initial
design, setup, and qualification, it degenerated into nothing more
than a visual sales gimmick to impress potential customers. *Looked
good through the conveniently located viewing windows, but never again
acheived anything remotely close to what a true HEPA filter is
designed to do.

Putting a true HEPA filter in your home furnace/central AC or vacuum
cleaner is like dropping a 5 gal home aquarium filter in an outdoor
swimming pool. *IOW, totally useless. *You can call it what you like
but real HEPA filters are only truly effective in VERY closed and
controlled environments. *You wanna pay big bucks for a HEPA filter
while tons of particles are entering from a thousand other sources,
including your own body, fine by me. *It's your money. *Like those
view windows, sounds impressive and it's a good selling point.

nb *

My dogs shake off more particles than a Hepa room would allow