Electrostatic vs. HEPA Furnace Filters

Many people prefer to use high efficiency furnace filters in their homes in order to reduce allergens or the effect of cigarette smoke, or simply because they want the best air quality that they can get. Hospitals and laboratories are excellent examples of the latter case. On average these individuals will chose to buy filters with a MERVE rating higher than 10, preferably between 13 and 20 in particular. High efficiency particulate arresting (HEPA) filters are the most commonly used filters in this respect, but more and more often they are being replaced by new electrostatic filters instead.

The main reason for this phenomenon is simply design. HEPA filters have dominated the market as the best filters that money can buy for a very long time. This is due to their design, wherein particles are sucked into an accordion shaped design that makes it nearly impossible to escape, and are then trapped in a fiber filter with a polymer side on the back. These filters suck up far more than 90% of particles in the air, yet they also reduce the airflow through the furnace and can need to be changed often.

Electrostatic furnace filters, on the other hand, are equally effective without the trouble. These filters can trap between 94% and 99% of all particles in the air, much like HEPA filters, yet are much easier to use. Unlike HEPA filters they do not need to be changed regularly, but rather washed every three months or so in order to ensure they work properly. Also unlike HEPA filters, electrostatic filters do not slow the air down even one bit.

Ultimately the two filters are not so radically different when it comes to performance. The electrostatic filters keep airflow going at top speeds, but they both catch a very large amount of dust and dirt particles in the air and keep your home clean. However HEPA filters need to be regularly replaced, and electrostatic filters just need to be washed. That difference is key, and is at the heart of why so many people are making the switch.