- The Danger
Particles that are less than 2 microns in
size will enter and remain in the lung linings and
These particles can contain, mold, fungus,
bacteria, pollen, dust mites, dust mite feces and
other airborne respirable allergens. These
are the particles you need to remove from your
The Big Lie
There are those that would
have you believe that a washable type
electrostatic air filter will protect you from
these harmful particles. They don't...never
did. In fact most electrostatic air filters are
less then 10% effective in
capturing dangerous respirable particles.
- Well it would be
pretty hard to sell any of these washable
electrostatic air filters if they advertised a
whopping 10% efficiency rating.
Instead sellers of washable electrostatic filters advertise the results of a
test that measures an air filters ability to
capture large particles.
This test "the average
synthetic dust weight arrestance test" has only one
use, it gives the people selling the washable
electrostatic air filter a high number to hype.
So the next time someone tries to sell you a
electrostatic filter with a 95%
efficiency air filter, ask
them what the dust spot efficiency is?
how the tests work
Synthetic Dust Weight Arrestance Test
test measures a filters ability to remove
large particles. Most large particles are to
heavy to stay suspended in the air and soon fall to
the ground. Small particles are the ones
which have the greatest potential to aggravate
An air cleaner is
mounted in a clean test duct. A highly efficient
filter is carefully weighed and mounted downstream
from it, and then a measured quantity of synthetic
dust is released into the duct. The downstream filter
captures particles that get through the air filter.
filter is weighed again, and the pre- and post-test
weights are compared to establish a rating.
Dust Spot Test
test accurately represents an air filters ability
to capture fine respirable
An air filter is mounted
in a clean test duct, with highly efficient filters
mounted upstream and downstream from it. Outdoor air
is then introduced into the duct. The upstream filter
catches a sample of airborne particles before they
reach the air filter, providing a bench mark for later
comparison with the downstream filter.