The general recommendation for replacing furnace filters is every 3 to 4 months for MERV 8, every 6 months for MERV 10 and 11, and every year for MERV 16. However, if the filter is made of fiberglass, experts suggest changing it every 30 days. Pleated filters can last up to three to six months, while MERV 13 should be replaced every 9 to 12 months. When it comes to MERV 11 or higher, these filters usually require two filter changes per year. If the filter is designed to last 90 days, it should be changed every 30 days during peak summer and winter months when the HVAC system is running at its maximum capacity.
If an air filter is not replaced, the appliance will attract more particles from the surrounding air, leading to inefficiency. On the other hand, smaller rooms won't require much air pumping, which means a lower frequency of filter replacement. The replacement cycle of the air filter and oven filter is also affected by air outside and inside the house. If you have poor outdoor air quality or pets indoors, you'll need to change your air filter more often.
As a general rule, pleated air filters and oven filters should be replaced every 90 days. If you use a more efficient filter (MERV 11 or higher), you may need to change it more frequently as they may cause air restriction due to their larger surface area. Following the right filter replacement program will ensure that your family breathes clean, fresh air and stays healthy. How often you should change your home air filter depends on the type of filter, its thickness, the MERV rating, and some special conditions.
A home that is occupied most of the time will require more frequent use of the air conditioning system and therefore will need to replace the filter much sooner compared to a house without occupants.
