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