What is an Electrostatically Charged Filter?

The term “electrostatic air filters” can refer to either an air purifying unit that utilizes electricity to charge particles or a disposable filter panel that is usually placed in a heating, ventilation and air conditioning (HVAC) system. These filters are made of a filter medium that has undergone a process to give it an attractive quality. In some cases, multi-layer washable filters contain layers of materials that are designed to charge particles as they pass, making it easier for the attractive filter layer to work. So, how do electrostatic air filters work? While a standard air filter is effective enough to filter out larger particles from the air, it fails to capture some of the smaller particles. This is where electrostatic air filters come in.

They use the natural phenomenon of static electricity to capture particles in the air. Air filters serve to remove contaminants from outside air that is recirculated through the HVAC system. An electrostatic air filter is made of metal and uses static electricity to give particles a positive charge when they enter the filter. Air travels over the metal surface, creating static electricity, similar to socks that slide across the carpet. Electrostatic air filters are air filters that filter particles using static electricity.

If you've seen washable metal air filters, then those are electrostatic air filters. An electrostatic filter is made of electrically charged media. This type of air filtration system uses two plates - one has a positive charge and the other has a negative charge. The positively charged plate attracts negatively charged particles while positively charged particles are attracted to the negatively charged plate.

All electrically charged particles in the air in your home will be attracted to one of these plates. The particles stick to the plate until its surface is washed. Electrostatic filters come in one size only and fit almost all heating and air conditioning systems. However, it should be noted that some disposable pleated air filters also use electrostatic attraction to filter particles. Electrostatic air filters with a flexible frame meet the same specifications as filters with a rigid metal frame.

Fibreglass filters may contain something like a static charge, but it's not enough to turn them into an effective filtering device. Choosing an electrostatic air filter can lower your utility bills because your heating and cooling system will be able to operate at its highest level of efficiency. As mentioned above, pleated filters fall into two categories when talking about electrostatic air filters - one type uses static electricity while the other type uses layers of materials that are designed to charge particles as they pass. The particle is trapped before it releases its charge as air continues through the subsequent layers of the filter. To maintain maximum filter performance, I recommend cleaning the electrostatic filter at least once a month. If you want to further improve your home's indoor air quality, electrostatic filters are compatible with UV-C air purifiers, whole-house fans, attic fans and portable air purifiers.

In fact, the terms “washable air filter” and “electrostatic air filter” have become interchangeable, since most electrostatic air filters are of the washable metal type. When cleaned according to instructions, these types of filters will provide you with many years of trouble-free use. For example, if you're replacing a 25 x 25 inch disposable filter, you'll need a standard size 25 x 25 inch electrostatic air filter.