Your Furnace’s Air Filter: Small Part, Major Role

Picture the spark plugs in your car. Depending on the engine type, you might have from four to eight of them.

They are small and tucked away, yet without them your car would not start. They are vital to the engine’s internal combustion that provides the energy for motion. Compared with other car parts, the spark plugs are also inexpensive to replace.

The air filter has a similar relationship with your furnace. It is a small, low-cost component with a crucial role in heating your home. Because it is small and tucked away – much like a spark plug – it too is frequently forgotten.

Even though about 90% of U.S. homes have HVAC systems, many homeowners tend to overlook the air filter. One recent poll of 1,000 Americans found that:

29% never change their air filter

82% do not change it monthly

31% of those who do change it do so every few months

Dirty Furnace Filter: Problems

Consider what happens to a furnace simply because of a dirty air filter in Naperville, Aurora, Plainfield, Oswego and Lisle:

reduced air flow. A clogged filter causes dust, dirt and other pollutants to build up in the blower fans and air ducts, decreasing the system’s ability to move heated air freely. This can produce cool instead of warm air, as well as uneven temperature spots throughout the home.

The furnace also will labor more to distribute heated air into the home. This keeps the heat near the furnace. If it rises too much, it can trigger a shutdown. The system then won’t be able fire back up until the heat has dissipated. If the filter remains dirty, the sequence will only repeat.

cracked heat exchanger. Excess build-up of heat can stress the heat exchanger and make it crack, leading to one of the most expensive furnace repairs. Beyond the expense and inconvenience, a cracked heat exchanger can release combustion gases such as carbon monoxide, sulfur dioxide and nitrous oxide into the air you breathe.

short-cycling. Because it prevents consistent communication between the furnace and the thermostat, a dirty air filter will often cause the heating system to shut on and off in short cycles throughout the day.

poor indoor air quality. An increasingly dirty filter will no longer be able to trap impurities moving through the system. Rather, it will start to reintroduce what it has trapped back into the indoor air. Beyond lowering the quality of breathable air, this can aggravate conditions such as allergies and asthma.

The Environmental Protection Agency says that our indoor air can often be more polluted than our outdoor air. A report by the University of Rochester Medical Center also cites indoor air pollution as a threat to good health, something to consider as we move further into the cold and flu seasons.

moisture and mold. A dirty filter can cause moisture to develop in the ducts. If they remain damp, mold can grow and quickly spread through the home.

frequent repairs. Problems that begin with a clogged filter can advance to needed repairs and unexpected expenses. You might be surprised by how often we find a clogged filter to be the reason behind a furnace repair.

shorter system life. A well-maintained furnace these days can often serve a home for a good 15 years, if not longer. If the filter isn’t consistently changed, the wear and tear it puts on the heating system can lower its lifespan by years.

higher energy costs. Poor airflow, short-cycling and failing parts cycling all force the furnace to draw extra power for operation. In particular, if the blower fan circulating your heated air becomes overworked, energy usage can leap. Changing the filter on a schedule can help you maintain control of your bills.

Clean Furnace Filter: Benefits Enjoyed

As you can see, it’s remarkable how much can unravel simply from not replacing the filter. Now let’s look at it from the other side.

By changing the filter regularly, you can help:

circulate indoor air with fewer impurities

conserve energy (the Department of Energy suggests up to 15%)

contain your utility bills

avoid expensive furnace repairs or system replacements

extend the life of your heating system

This list is better – and easier to read – than the one in the previous section, wouldn’t you agree?

When Should I Change My Furnace Filter?

Most sources, including the EPA, will agree that here in Aurora, Oswego, Plainfield, Naperville and Lisle, an air filter should be changed every 60 to 90 days on average.

The filter should be checked more often when the system is working harder, such as during the bitter cold of January and February. You’ll also want to check the filter more often if you have pets and if you keep the windows open during fall.

Your replacement frequency may further depend on the quality of the filter. Disposable fiberglass filters with a MERV rating of 1 to 4 will usually last about a month. Pleated media filters rated a MERV 8 or higher can last a few months.

Here for Answers and Service

Beery Heating and Cooling is a team of skilled and friendly professionals dedicated to helping make sure you stay warm when it’s cool out in Naperville, Aurora, Plainfield, Oswego and Lisle. If you would like to discuss air filters for your home, just give us a call at (630) 585-6444. Ask us about furnace maintenance and air-quality systems as well!

Quick Air Filter Tip

You can help extend the life of the air filter by keeping the system fan set to “AUTO.” This ensures the blower fan runs only when the furnace does. Having the fan set to “ON” will make it run all the time, even while the furnace off. Air will continue circulating through the home and heating system. As more air passes through the filter, the filter will keep trapping particles and become dirtier faster.