Now Hiring! See our open positions. Read More

Skip navigation


Serving The Twin Cities Since 1991


Residential Heating and Air Conditioning Blog

Furnace Filters and You: An Educational Tale


Do you know that your home’s furnace has a filter? We hope so, since it’s an essential part of the whole HVAC system, not just the furnace, and it requires special attention during the year. The furnace filter is sometimes called the blower filter if it’s used for both the furnace and the air conditioning system. It’s often just called an air filter.

This filter can sometimes create confusion in homeowners, who often don’t know exactly what it does or what they need to do about it. We want our customers to have the information they need to ensure the best performance from their heating system and the lower costs to keep their homes warm, so we’re going to take time to talk about what you need to know about furnace filters in Eden Prairie, MN or wherever you live in the Twin Cities.

The Job of the Furnace Filter

Quick: Can you describe what the furnace filter does?

You might answer “It filters the air.” After all, that’s what most people think filters are for with any type of forced-air system. It’s a natural reaction, but it’s not correct.

The furnace filter can have a minor, beneficial effect on the quality of the air in a house, but that’s only a slight additional benefit. It’s not the furnace filter’s actual job. The actual purpose of this filter is to protect the interior of the furnace and the blower assembly from dust and dirt infiltration. 

The filter is placed along the return air duct for the home, the duct that draws air from the inside of the house, so it can move through the furnace and receive heat. Any air that comes through the return duct will bring with it debris such as lint, dander, dust, etc.

If these particles get into the furnace cabinet, they can cause damage: placing extra strain on motors, blocking the burners, obstructing the flame sensor, and hindering the ignition system. Any amount of dust in the furnace will create stress on the system that will make it work harder and age faster. With the filter in place, most of the debris won’t be able to reach the furnace interior. 

Furnace Filter Maintenance

The filter will become clogged after 1-3 months, depending on the strength and thickness of the filter. At this point, the filter becomes a hindrance to the furnace because it will make it harder for the system to pull in air. This means more strain and less air to get heated. Many common furnace malfunctions occur because a clogged filter remains in place. 

During routine furnace maintenance with our team (schedule it annually!), we’ll change the furnace filter. You will need to change it yourself through the rest of the season. These filters are available at our office or we can deliver them for free if you order two or more. Our experts will match the filter to your HVAC system so it does the job necessary without overtaxing the furnace. 

Rely on Residential Heating and Air Conditioning and you’ll “Feel the Difference”! Serving The Twin Cities Since 1991. 

Comments are closed.