In general, most air filters should be changed every 90 days or 3 months. This may vary depending on the location of your home, if you have pets, and the age of your system and equipment. The only way to know for sure is to inspect the filter every month. After a few months, you'll get an idea of how quickly it gets dirty.
You may need to reassess if you have a new pet or if the outdoor air quality has been poor. Depending on your lifestyle and the type of filter you choose, you may want to change it more often. Most filter manufacturers recommend how often their product should be replaced. A general rule of thumb for pleated air filters (such as those manufactured by FilterBuy) is to replace the filter every 90 days.
As the filter traps more dirt, dust and allergens from the air, its efficiency decreases. In unoccupied suburban homes without pets, it is usually enough to change air filters once a year (every 12 months). However, if you have pets, live in a city center, or have other factors that increase air pollution, you may need to change the filter more often (up to 20 days). Not changing your air filter often enough can lead to higher energy bills as clogged filters cause the system to work harder when air circulates.
It can also worsen symptoms such as coughing, sneezing, and runny nose due to excessive dust, pet dander, and other allergens floating in the indoor air. To ensure that only clean air comes out of your HVAC system, replace the air filter before it becomes clogged so that you can breathe better. It involves loosening the screws that hold the filter cover in place if it is located behind a return air vent or simply pulling the filter out of a slot if it is on the side of the oven. A good rule of thumb is that if debris needs to be vacuumed more frequently from the floor, it can be safely said that this debris also goes to the air filters.
The answer to how often air filters need to be changed doesn't have a one-size-fits-all answer. To ensure optimal performance of your HVAC system and good indoor air quality, check your household air filters or oven filters regularly and replace them before they become clogged.