Do Furnaces Have a HEPA Filter?

Air Filter

Furnace filters do an essential job of keeping both the furnace working properly and ensuring better indoor air quality. The principal function of these filters is merely removing unwanted air particles from moving throughout your ductwork. That particle clearance safeguards the blower fan in the furnace and the house residents by preventing contaminants from recirculating back into the air.

The dirt and particles will typically accumulate on the furnace filter. That is why it is crucial to change it regularly. If the filter is clogged, it is likely to cause many issues, including reducing the furnace’s efficiency and possibly damaging it while lowering your indoor air quality. Be sure to schedule routine maintenance or furnace repair to prevent these issues.

Where is your Furnace Filter Located?

Your furnace air filter is located on your furnace, where the air returns to the unit. Look for a large square or round metal duct that attaches to the furnace’s side or bottom. Your furnace filter should be inside the air duct or furnace itself. The filter should be located between the return air duct and furnace blower motor assembly.

Filter Ratings

Furnaces can have filters with different levels of protection and fabric densities. Filters are measured with MERV, with a higher number denoting higher protection, as shown below:

  • MERV 6 filters can catch lint, dust, and pollen
  • MERV 8 filters can remove mold and dust mites
  • MERV 11 can cut smoke, smog, and pet dander
  • MERV 13 filters can minimize the spread of airborne bacteria and viruses

Filters with higher ratings are typically meant for hospital use and are not necessary for residential environments. In most cases, MERV 11 will give you the best balance between stopping those fine air particulates without necessarily impeding airflow or causing furnace damage leading to the need for furnace repair.

What About HEPA Filters?

HEPA, high-efficiency particulate filters, are high-grade air filtration solutions that remove up to 99% of the tiniest air particles. Nevertheless, since these filters use a significantly denser filtration material, they can overwork your furnace. Installing a HEPA filter in your furnace is not recommended as it would considerably restrict the airflow.

If you’re looking for the best filtration possible, then start by looking at your manufacturer’s recommendation for the highest filters their furnaces can handle. Keep in mind that high-rated filters may exert more strain on furnace systems, potentially burning out motors and worsening the air quality. Consulting with a furnace repair firm can also help guide you in choosing the right filter.


Using the right HVAC or furnace size and filter will ensure the best results for filtering air particulate without restricting airflow in your house. Your furnace does a lot to clean the air in your home, it is essential to ensure that it is always running smoothly. Reach out to Kelly’s Heating & Cooling Inc. today for your entire commercial and residential furnace repair needs. Our team of experienced professionals is ready to help you. Call us at (801) 282- 9952 to schedule an inspection now!