How Long Does a 4-Inch Filter Last?

When it comes to air filters, size matters. Most HVAC technicians recommend changing 1-inch air filters every 30 days, while 4-inch filters can be changed every 3 to 6 months. For example, a one-inch oven filter should be changed every one to three months. A three- to four-inch filter can last six to nine months.

If you have a five- to six-inch coarse-grained filter, it can last nine to twelve months. If you have multiple animals in the house, you'll need to adjust the frequency of filter changes. For 1- to 2-inch filters, replace them every month; for 4-inch filters, replace them every two months; and for 5-inch filters, replace them every three months. Pets can also be an excellent reason to consider an improved or superior MERV filter for your HVAC system.

Windows and doors that are left open allow dust and pollutants from outside air to build up in your home and put an extra layer of dirt on the air filters. When the oven filter is clogged with contaminants, air cannot flow properly through the system. And the best filters trap indoor contaminants, such as dust, pet dander and pollen, helping to clean the air in your home. If you have multiple smokers in the house, you'll need to adjust those numbers to once a month for one- to two-inch filters, two months for four-inch filters, and three months for five-inch filters.

For an animal that lives at home, you should replace the filter every two months with a one- or two-inch filter, four months with a four-inch filter, and six months with a five-inch filter. When considering a filter change, you may want to look at how much shed your pet is sheltering or how many pets you have, as that can be a factor in determining how often you'll need to check or replace the filter. However, northerners whose ovens don't rest for months may want to change their filter every 30 to 60 days, as more air passes through the filter and it will clog up more quickly. One of the most important things you can do on your own to take good care of your air conditioning system is to simply change your air filter regularly. If you answer yes to this question, you'll want to change your filter every 6 weeks to maintain the best indoor air quality. It consists of loosening the screws that hold the filter cover in place if it is behind a return vent or simply removing the filter from a slot if it is on the side of the oven.