What Are the Restrictions of HEPA Filtration on Airflow?

As filtration efficiency increases, so does the restriction of system airflow caused by the filter. Therefore, HEPA filtration is not suitable for all residential systems. An HVAC contractor can measure airflow and tell you if your system is compatible with HEPA filtration built into ductwork. As an alternative, residential HEPA filtration options include whole-house air filters that connect to ductwork through a bypass circuit.

These units draw air from the duct, transport it through the HEPA filter array, and then reintroduce it back into the duct without restricting air flow. The high-efficiency particulate air filter (HEPA) is the best in air filtration and removes more than 99% of particles of 0.3 microns or larger. However, due to the dense filtration material used in HEPA filters, the air pressure needed to force air through the filter is too high for an air conditioning fan or oven to withstand. A HEPA filter installed in an oven would restrict air flow to such an extent that no air would come out through the vents. However, traditional air filters that are in the higher range of MERV ratings (12-1) approach HEPA filtration levels, with the exception of virus removal. While most use air filters to help reduce indoor air pollution, some simultaneously reduce airflow, either because they are dirty, inefficient, or too efficient.

With that said, it's important to find the right air filter to remove contaminants from your home while maintaining consistent airflow. While good for stand-alone air purifiers and for private uses, this level air filter in an average household system dramatically reduces airflow. The only time you can use a HEPA air filter in your home is if your system is compatible or requires a HEPA air filter. Sobieski Services is at the forefront of ensuring healthy indoor air quality with efficient air filters. When looking for an air filter, it's important to find one that traps contaminants and allows air to flow freely. Usually, the only time you would need a HEPA air filter in your home is if your house was built to accommodate the use of HEPA filters or if your HVAC system has been modified to allow the installation of a true HEPA system, which is very expensive.