Air Filtration

What are airborne particles and where do they come from?

You may be surprised to learn that some common household items pollute the air you breath, including: pollen and spores, human skin flakes, candle soot, infiltrating dust, viruses, bacteria, and fungi, pet dander, tobacco or wood smoke, cooking smoke and airborne grease, radon gas, chemical fumes and volatile organic compounds.  Every cubic foot of air you breath carries a mixture of millions of such airborne particles.  Although larger particles are more visible and catch attention more easily, the smallest of these particles are of greatest concern for indoor air quality.  Viruses, bacteria, smoke and grease are amongst the smallest and can be most damaging to the home and the individuals who live there.

Central system air cleaners and filters are generically categorized by:

Basic Filters, which come standard with most HVAC systems. These filters protect the furnace from bulk dust that can clog equipment before the warranty runs out; they do little to clean the air of smaller particles.

Media Filters, which filter the air using webs of polypropylene fibers to strain, intercept and diffuse airborne particles.

Electronic Air Cleaners, which electrically charge and collect airborne particles on a collection grid. Many electronic air cleaners capture up to 100% of airborne particles passing through the product.

High-Efficiency Particulate Air (HEPA) Filters use deeply folded media to trap a minimum of 99.97% of 0.3 micron particles passing through the filter. HEPA filters come in portable, bypass ducted and stand-alone configurations. Beware of manufacturers who use terms like "HEPA-style" or "HEPA-like" filters. Many manufacturers offer HEPA-style filters, but they may only be HEPA at initial efficiencies or by circulatiing air through the filter numberous times.