Frequently Asked HVAC Questions

What Are the Different Types of Furnace Filters?

There are several different types of furnace filters that can work with your furnace. The options consist of fiberglass/synthetic filters, polyester filters, electrostatic filters, pleated filters, and HEPA filters. You also have the option choosing a disposable or washable filter based on the needs and requirements of your current system.
 

Furnace Filter’s Job

It is the responsibility of the furnace filter to protect the blower fan by removing airborne particulates from the air drawn in through the return ducts. Dust, pollen, pet dander, and other pollutants reduce your indoor air quality, decrease your heating and cooling system’s efficiency, and lead to mechanical failure. The type of filter you install in your furnace will affect the furnace’s performance and lifespan. Aside from the different types of furnace filters listed below, you want to make sure you have the right size filter, so your system doesn’t suffer from escaped dirt and debris, which restrict your airflow.
 

Fiberglass/Synthetic Filters

Fiberglass or synthetic filters are a cheap and disposable option for your furnace. They catch up to 80% of particles 50 microns and larger and 25% of particles between 3 to 10 microns. Considered minimum protection, fiberglass/synthetic filters prevent dust and dirt from building up on heat exchangers, fan motors, and other surfaces. The larger particles are trapped and eliminated, so your furnace components remain clean. They allow your system to have maximum airflow but don’t filter harmful contaminants affecting your health.
 

Polyester Filters

Polyester filters are made using the highest quality materials available and are median-sized. They trap and eliminate 80% to 95% of particles 5 microns or larger. A polyester filter costs fours time more than the average fiberglass/synthetic filter, but it offers more protection against pollutants that cause health issues.
 

Electrostatic Filters

Electrostatic filters use self-charging fibers to attract particles out of your air. You can purchase disposable or washable electrostatic filters depending on the requirements of your furnace. Washable versions offer a MERV rating between 4 and 10 and last considerably longer than the average filter. Maintenance on a washable filter requires soap and water to wash the filter and letting it completely dry before reinstalling it. If you install it before it completely dries, you run the risk of mildew and mold growth.
 

Pleated Filters

A pleated filter offers high-efficiency results by trapping particulates 0.3 micron in size, such as bacteria and viruses. Pleated filters are more efficient and last longer compared to fiberglass/synthetic filters. They eliminate more pollutants from your air without sacrificing airflow within your system.
 

HEPA Filters

High efficiency particulate air, or HEPA, filters provide high-end filtration by trapping up to 99% of particles 0.3 microns or larger. Even though they are excellent at eliminating indoor pollutants and create a healthier environment in your home, they can drastically reduce your system’s airflow, costing more money in energy usage.
 

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