How Often Should You Change Your Furnace Filter?

When it comes to maintaining a healthy central air system in your home, regular AC air filter changes are well-known among homeowners. However, some may overlook the importance of changing their furnace filter at appropriate intervals.

Every central air system with a heating component has a crucial part known as the "furnace." This furnace plays a significant role in the HVAC air filtration system by taking in cold air, heating it up, and then distributing it throughout the house via the air handler.

Comprising essential components like the heat exchanger, combustion chamber, and air blower, the furnace efficiently conditions the air inside your home. A key player in this process is the furnace filter, which is responsible for cleaning the air.

Now, you might be wondering, how often should you change your furnace filter? Let's delve deeper into understanding your home's furnace filter, its functions, and the reasons behind maintaining a regular furnace filter replacement schedule.

What Does a Furnace Filter Do?

A furnace filter plays a vital role in a home's heating, ventilation, and air conditioning (HVAC) system. Its primary function is to improve indoor air quality by capturing and trapping various airborne particles, ensuring cleaner and healthier air for the occupants. This simple yet essential component acts as a barrier between the outside environment and the indoor living spaces, providing numerous benefits that contribute to resident's overall comfort and well-being.

The primary purpose of a furnace filter is to remove dust, dirt, pollen, pet dander, mold spores, and other contaminants from the air as it circulates through the HVAC system. As the furnace pulls in air to be heated, the filter intercepts these particles, preventing them from entering the ductwork and eventually being dispersed throughout the house. This not only keeps the indoor air cleaner but also safeguards the HVAC equipment from damage caused by the accumulation of debris.

How Often Is Changing Furnace Filters Necessary?

The frequency of changing furnace filters can vary depending on the type of filter used and the specific characteristics of your home. To keep your HVAC system running efficiently, it's crucial to know when to replace the filter.

Furnace filters come in various types, and their replacement intervals can range from monthly to yearly. You don't have to guess when it's time to change them, as the manufacturer usually provides recommended replacement frequencies in the product information that comes with a new filter.

Size plays a significant role in determining how often you should replace your furnace filter. Thicker filters with more media can absorb more pollutants, meaning a 5-inch filter will need fewer replacements than a 1-inch filter. Another factor to consider is the filter's efficiency, measured by the MERV rating (minimum efficiency reporting value).

Here's a quick guide for filter replacement based on size:

1- to 2-inch filters: Replace every 1 to 3 months.

3- to 4-inch filters: Replace every 6 to 9 months.

5- to 6-inch filters: Replace every 9 to 12 months.

Besides size and efficiency, there are other important factors to consider when changing furnace filters to maintain a healthy and comfortable indoor environment. By staying informed about the type of filter you have and following the manufacturer's recommendations, you can ensure that your HVAC system works optimally, providing clean and fresh air for your home.

Home Occupancy

The number of people who live in a house influences the life span of a furnace filter. Filters are changed more frequently in large households than in places with only one or two residents. People contribute various contaminants to the home environment; thus, the more people in your house, the more pollutants the filter will have to trap. Presence of Pets in the House Pets are another significant source of pollutants in the indoor air supply. These furry family members shed fur and dander, which the HVAC system picks up and circulates in the home. The useful service life of a filter is reduced by around 30 days for every furry family member residing in your house, so you would need to replace furnace filters more frequently.

Indoor Air Quality

Furnace filters won’t last as long in a home that has poor indoor air quality as they will in a house with acceptable indoor air quality. Indoor air quality devices, such as air purifiers and air cleaners reduce pollutant volume, resulting in fewer particles for your furnace filter to absorb. In houses without this equipment, the furnace filter becomes the sole line of defence against airborne contaminants, so it fills up faster, and as a result, it will need to be changed more often.

Allergic Reactions

Family members who suffer from allergies or asthma can influence the frequency with which you change your furnace filters. This helps to guarantee that toxins causing symptoms are eliminated from your indoor air supply.

Heating & Cooling Usage

Filters have a shorter functional service life when the home's heating and cooling equipment is widely used - air is cycled more often, so the filter has more opportunity to take up contaminants and get blocked.

What Could Happen If Furnace Filters Are Not Changed Regularly?

Various issues happen when regular furnace filter changes are neglected or skipped. Some of these problems include:

Damage to the HVAC System

When the furnace filter is not changed regularly, airborne dust, dirt, and other debris accumulate and worsen the furnace’s performance, even causing damage to components. Also, when filters become clogged yet the HVAC system continues to function, air does not circulate efficiently. Heating and cooling equipment expends more energy to push air forward when a filthy filter blocks its passage. This additional labour strains the system's components, using more energy and causing equipment damage.
Apart from these, a dirty filter restricts airflow and elevates the temperature within the HVAC system, causing it to overheat. After cooling, it restarts, but the problem remains — this is known as short-cycling, and dirty filters are the most typical reason. Short-cycling causes HVAC system damage that necessitates repair and premature total system failure, as well as increased energy consumption, higher utility bills, and decreased interior comfort.

Poor Comfort & Air Quality

Since airflow is hindered when furnace filters are not changed, living spaces do not receive an adequate quantity of heating and cooling. It is difficult to maintain comfort levels, and home occupants frequently notice hot and cold patches. Also, when the filter is clogged, there is no more surface area to absorb new particles as they pass through. As a result, those pollutants linger in the air supply and travel back into your house, causing allergy symptoms, respiratory troubles, body irritations, and dirtier surfaces regardless of how regularly you clean.

How Do You Know The Kind Of Furnace Filter To Buy?

There are several types of filters available. To keep things easy, get the same size filter you currently own. Before you rush out to the hardware shop, take measurements and thickness of your present filter. It would be best if you also wrote down the brand name or snapped a picture of the entire thing to compare at the store. It would help if you also took note of the MERV rating of the filter you want to purchase because the higher the MERV, the higher the efficiency and the better the filter is at trapping particles.

Conclusion

Changing your furnace filter regularly is a simple method to preserve healthy air quality in your house, keep your furnace in excellent working order, and even save money on energy bills.

Or Select Popular Sizes