{"id":2167,"date":"2018-12-04T11:05:46","date_gmt":"2018-12-04T16:05:46","guid":{"rendered":"https:\/\/www.purlsheetmetal.com\/blog\/?p=2167"},"modified":"2025-09-11T08:55:13","modified_gmt":"2025-09-11T12:55:13","slug":"how-long-furnace-filter-last","status":"publish","type":"post","link":"https:\/\/www.purlsheetmetal.com\/blog\/how-long-furnace-filter-last\/","title":{"rendered":"How Long Will My Furnace Filter Last?"},"content":{"rendered":"
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California has recently experienced a series of major fires. Thankfully for us in the Central Valley, these fires were in the north and south of the state. But we\u2019re not strangers to these disasters: last summer wildfires scorched more than 1700 acres in Fresno and Mariposa counties. This caused a plunge in air quality for surrounding areas. When this happens, we recommend making an immediate change to the furnace filter on your HVAC cabinet. Otherwise, extra pollutants trapped in the filter will further drop indoor air quality. For more on this, here\u2019s<\/span> why changing your air filter matters<\/span><\/a>.<\/span><\/p>\n\n\n\n\n\n\n\n

But how long will the furnace filter last under normal conditions?<\/h3>\n\n\n\n

This is a good question, since changing the filter regularly is an essential part of protecting your furnace, your comfort, and your energy bills. If you’re unsure how this ties into performance, learn<\/span> ways to improve home heating<\/span><\/a> and extend your system\u2019s efficiency through the colder months.<\/span><\/p>\n\n\n\n

First, a word about what the furnace filter is for. It\u2019s not<\/em> to improve air quality in the house. It can cause air quality to decrease<\/em> if left in place too long, but its normal function isn\u2019t to clean the home\u2019s air but to protect the furnace. The filter cleans the air coming through the return air ducts and into the furnace cabinet. The blower fan in the air handler pulls air from the house through vents, then sends the air through the furnace to warm it and on into the supply ducts. The furnace filter stops dust and other debris brought in through the return ducts from contaminating the inside of the unit and harming its ability to work at peak condition.<\/p>\n\n\n\n

The filter stops most larger particles that may come through the return ducts: household dust, lint, dander, etc. In most cases, the filter is located either behind the grill of the return air vents or next to the air handler where the return ducts connect to it. To change it, simply slide out the old filter and put in a new one.<\/p>\n\n\n\n

How long the filter can go before needing a replacement depends on several factors:<\/p>\n\n\n\n