Air Filters: Should You Be Using HEPA Filtration?

Air filters in your HVAC system are the front line in the battle for healthy indoor air quality. Unfortunately, what is generally installed as standard equipment may not be getting the job done. Inexpensive, disposable flat panel filters are primarily designed to protect mechanical HVAC components from wear and tear caused by large inorganic dust particles. They aren’t made to address human air quality issues caused by microscopic organic airborne contaminants. HEPA (high-efficiency particulate air) filters close the gap and take air filtration to a higher level.

Filter efficiency is rated by the MERV (minimum efficiency reporting value) system, ranging from 1 to 16. The higher the MERV rating, the more effective the filter is at safeguarding your indoor air quality. Standard panel filters have MERV ratings from 1 to 4 and generally remove air particles no smaller than 3 to 10 microns. HEPA filters exceed MERV 16. These air filters remove 99.97 percent of particles down to a size of .3 microns.

HEPA filters are the gold standard in hospitals and clinics because they remove not only inorganic dust, but microorganisms such as mold spores, bacteria, pollen, dust mites and many viruses. Instead of flat fiberglass media in standard filters, HEPA utilizes pleated media to substantially increase the surface area for filtration as well as the filter’s service life.

As filtration efficiency increases, so does restriction to system airflow caused by the filter. Therefore, HEPA filtration is not suitable for all residential systems. An HVAC contractor can measure the airflow and tell you if your system can accommodate in-duct HEPA filtration. As an alternative, residential HEPA filtration options include whole-house air filters that connect to ductwork via a bypass loop. These units draw air out of the duct, convey it through the HEPA filter array, then loop it back into the duct without restricting airflow.

Sobieski Services is in the front line of ensuring healthy indoor air quality with efficient air filters.

Our goal is to help educate our customers in Delaware, Pennsylvania, Maryland and New Jersey about energy and home comfort issues (specific to HVAC & plumbing systems).

Image Credit: massdistraction