How often to change your air filters can depend on several factors:
- the type of air filter you are using
- the overall air quality of your home
- pets, pets, pets..
- occupancy of the home, and
- the level of air pollution and construction around the home
For standard 1" air filters, the manufacturers basically tell you to change them every 30-90 days, which is actually a great rule of thumb. But general rules aren't always for everybody. If you suffer from light to moderate allergies, you could upgrade the air filter or change them even more often. Or, if you're in a more remote area, less occupied home (like a vacation home) and there are fewer cars around, semi-annually may be quite sufficient. Why do pets matter so much? They have a tendency to shed, which can clog your air filter quick and with great success. Of course the air filter is just doing its job by capturing pet hair and dander, but extremely dirty filters can cause extremely weak HVAC performance.
Here is a basic guideline for when you should change your filter:
- Vacation home or single occupant w/o pets or allergies: 4-6 months
- "Average" suburban home w/o pets: every 90 days
- Add a dog or cat: every 60 days
- Add more than one pet or have allergies: 30-45 days