- Angie changed the 312 furnace filter by Collin Anderson, on Flickr
The reigning wisdom on the subject of dust and furnace filters is that it is better to buy a less stringent (and less expensive) filter and change it more frequently. This is because the super-duper filters cause your furnace to work harder trying to force air through the fine filter. The life expectancy of the less expensive filters is stated as 30-90 days. However, the best advice suggests you change these every month. We have used these inexpensive filters for awhile now. What I have found is that our furnace filter could (and probably should) be changed once a week, as opposed to once a month as suggested by the experts… I am hoping the March winds will soon blow all talk of furnaces away, bringing sunshine, fresh warm air and spring into our steps.