HEPA (high effeciency particulate accumulator) filters are the gold standard for allergy particulate removal. They remove 99.97% of particles larger than .3 microns and are used in many freestanding units. The glue used in some of these filters may affect people with chemical sensitivitivies. They may be bonded with polyvinyl acetate, plastic or other resin binders, possibly containing formaldehyde, acrylic, or silicone. The outgassing from the filter itself may cause reactions. However, nonpetrochemical HEPA filters are available. There are also vacuum cleaners that offer HEPA filtration. The dense pleated accordion shape creates strong air resistance that can strain the motor of an air handler so a whole house HEPA filter is problematic. After extensive research, I found the freestanding Austin Air filters to be the best available both in terms of non toxic construction and parts, superior filtration and price.
99% of airborne particles are less than one micron.
viruses – 001 – .1
radon – < .001
smog – < .001 – 1.0
tobacco and wood smoke – .01 -1.0
cooking and grease smoke – .02 – .9
house dust – .00 -100
animal dander – .5 – 10
bacteria – .3 – 10
pollen – 6 – 100
mold spores – 1.0 – 100
visible to human eye – 10 upward
The Austin Air purifier has 60 sq ft of True Medical Grade HEPA, certified to remove 99.97% of airborne particles 0.3 microns and larger. It removes 95% of particles .1 microns and larger