Filter replacement frequency varies from house to house and from place to place. OTAF air filters are designed to last up to 90 days before needing replacement. If you have pets, or if you live in a location that has more dust, pollen or similar air particles, you may need to change your filter more frequently. We recommend checking your filter monthly. If you see that it is becoming dirty more quickly, you can sign into your OTAF account and increase the frequency of your filter deliveries. Sign up now for Filter Reminders and never forget when to replace your home’s air filters.