It is generally recommended to replace HVAC filters every three months.
Honeywellsuggests replacing the filter every 6 months to one year, depending on usage. FilterBuy pleated air filters should be replaced at least once every 90 days. As the filter traps more dirt, dust and allergens from the air, its efficiency decreases.
If you live alone, without pets and with good quality of the surrounding outdoor air, it is likely that the manufacturer's recommendations for changing the filter will work well for you. However, if you live in a northern area with no rest for months, or have poor air quality outside or pets indoors, you'll need to replace your air filter more often. Children are more sensitive than adults to indoor air pollutants, such as mold, dust mites, dander and pollen, so make sure to use quality air filters and replace them before they get too clogged and dirty. The Home Depot states that the air quality where you live can affect how often your oven filter needs to be changed.
Three- or 4-inch filters can last 6 to 9 months, and filters up to 6 inches thick can be replaced once a year. However, if you have a smaller appliance used to cool a small space, it often comes with smaller filters, so you may have to change the filter as often as a filter in a larger house. You may not have realized that your furnace filter needs to be changed because oven filters are not needed on all HVAC systems. If there is a visible layer of dirt covering most of the filter surface and that is thick enough to hide the filter material itself, it is a sign that the filter has been in the HVAC system too long.
Changing the oven filter regularly ensures that the air in your home remains free of dust and other contaminants. If your house has a lot of dust, you'll need to change the one- and two-inch filters every month, the four-inch filters every two months, and the five-inch filters every three months. Having multiple animals means you need to change a one or two inch filter every month, a four inch filter every two months, and a five inch filter every three months. Keeping new filters in your oven will help ensure that your oven runs smoothly and efficiently and, most importantly, that the air you and your family breathe is as clean as possible.