The general recommendation for replacing air filters is every 3 or 4 months for MERV 8, every 6 months for MERV 10 and 11, and every year for MERV 16. However, experts suggest changing them every 30 days if the filter is made of fiberglass, which is of relatively low quality. On the other hand, more expensive pleated filters can last up to three to six months. Specifically, filters with a MERV 11 rating or higher usually require two filter changes per year. During peak summer and winter months, when air conditioning systems are operating at maximum capacity, it is recommended to change the filter every 30 days.
This ensures maximum efficiency and smooth operation. If you use the air filter for less than five hours a day, you can extend the life of the filter to a few more months. This type has filtering capabilities similar to those of the MERV 8, but with additional efficiency for filtering pet fur. Filters with a higher MERV rating should be changed more frequently (at least every three months) to avoid airflow restriction, which can reduce efficiency or even damage the system.
The average efficiency range of the MERV 5-10 will probably require filter changes in about two to three months. If you have pets or people with allergies in your home, you should use an air filter with a higher MERV rating to collect more particulate matter. If you use a higher-efficiency filter (MERV 11 or higher), you may need to change it more often, as it can cause air restriction due to the larger surface area. How often you should change your home air filter depends on the type of filter, its thickness, the MERV rating, and some special conditions.
In addition to filtering particulates filtered by MERV 8 and 11, MERV 13 can filter kitchen smoke, smog, and virus carriers.
