Furnace Filter Types

The are several types of furnace filters. Each of these filters provide a different level of protection from airborne particles. The following is a list of the different filter types arranged from least effective to most effective:

Disposable fiberglass furnace filters - These are the least effective furnace filters available. They are designed to block only large dust and dirt particles to protect your furnace. They provide no real benefit to the air quality in your home.

Washable furnace filters - These filters come in a plastic or metal holders that allow you to use a hose to clean them off and reuse them. These furnace filters do save money over time, but the are no better then the disposable at improving the air quality in your home.

Electrostatic furnace filters - These filters have a static charge that attracts dust, dirt and other matter. While these filters are a bit more effective than disposable furnace filters, they still only block 15 to 20 percent of airborne particles. These will provide a minimal improvement to the air quality in your home.

Pleated furnace filters - These use a dense mesh material to trap particles. The pleats increase the surface area, eliminating large allergens like pollen and mold. These types of furnace filters are 35 to 50 percent efficient and will improve the air quality within your home. For their relativly low cost, pleated furnace filters provide a great value for how effective they are. Related Media Filters provide a thicker pleated media increase the filters efficiency.

Electronic air cleaners - These use electrodes to create an ionized electrical field that "magnetizes" pollutant particles and collects them on the filter material. An electronic unit can eliminate virtually all pollen and mold spores, up to 94 percent of smaller particles, and even up to 80 percent of airborne viruses. These will greatly improve the air quality within your home, but they are quite expensive and will typically require professional installation.

HEPA furnace filters - HEPA (High Efficiency Particulate Air) filters are used in commercial applications like hospitals, research facilities and electronics manufacturing where clean air is vital. HEPA filters provide the highest level of air quality. These are the most expensive filterrs and since they interupt air flow, they will require a bypass to the furnace returns so they do not interfere with the operation of the furnace.