How Often Should You Change Your Furnace Filter?
The frequency at which you change your filter depends on two main factors.
The first consideration are factors that contribute to a dirty filter. The number of people in the house, pets, carpets, how often you vacuum and the age of the house all contribute to the amount of dust and particles in the air. If you have a couple of kids and a dog, you’ll probably need to change your filter more frequently than a retired couple with no pets.
The second consideration is the size and type of the filter. Generally, older furnaces will have a filter that’s 1" thick. These filters can be flat or pleated. Pleated filters have more surface area and tend to last longer than flat filters. A 1" thick filter should be checked every 6 weeks and the frequency adjusted according to what you find. If it is really dirty you will want to replace it more frequently. If it still appears clean then wait a couple more weeks. At a minimum, 1" filters should be changed twice in the cooling season and twice during the heating season.
Newer furnaces may have a 4" thick filter that has an accordion (pleated) design. This provide much more surface area for catching dust and does not have to be changed as frequently. The minimum replacement schedule would be annually. We recommend that you check it before the air conditioner goes on in the spring and again when the furnace is going to start up in the fall. As with the 1" filter you may have to increase the replacement frequency if you have a busier household.
It is important to note that your air conditioner requires a clean filter so that it does not freeze up. Air has to be moving freely to prevent that from happening. Clean filters allow your equipment to run more efficiently, and to maintain a healthy environment.
Checking and changing filters is an easy task that most homeowners can do themselves. If you are not sure how to change your furnace filter, just ask our serviceman when you are having your annual maintenance done.
Salmon Plumbing & Heating, serving London, Ontario since 1955.