Water Filters

For most homes: every 60–90 days for MERV 8, every 60 days for MERV 11, and every 30–60 days for MERV 13. If you have pets, allergies, or your system runs hard during winter or summer, shorten that to 30–45 days. During peak heating season, a clogged filter forces your system to work harder, which can raise your energy bill and shorten equipment life. A 5-minute monthly visual check is all it takes.

For most homes, MERV 8 is the residential standard, it captures dust, pollen, mold spores, and dust mites without restricting airflow. If you have pets or mild allergies, MERV 11 captures fine particles like pet dander and auto emissions. If someone in your home has asthma, a compromised immune system, or you live in a wildfire-prone area, MERV 13 traps virus-carrying particles, bacteria, and fine smoke. One caveat: higher MERV ratings create more airflow resistance (static pressure). Always verify your system's manual before jumping to MERV 13.

Nominal size is the rounded number printed on the filter packaging (e.g., 20x20x1). Actual size is the true physical measurement of the filter (e.g., 19.75x19.75x0.75). Always check the actual size on your old filter before ordering. If you're using our custom filter builder, enter your measured actual size, we'll cut it to within 1/8 of an inch. Ordering the nominal size when you need the actual (or vice versa) is the most common cause of sizing issues.

It can, if your system isn't designed for it. Filters with higher MERV ratings (especially MERV 13+) increase static pressure, which forces the blower motor to work harder. In older systems or those with undersized ductwork, this can cause short cycling, reduced airflow, or in severe cases, a frozen evaporator coil. Always check your furnace or air handler manual for the maximum recommended MERV rating. When in doubt, MERV 8 or 11 is the safe default.

Yes. Air Filters Delivered is a direct-to-consumer brand of Con-Air Industries, Inc., based in Orlando, Florida. Aerostar pleated filters are manufactured in our Orlando facility, not imported or drop-shipped. That's how we can cut to custom sizes the same day an order is placed, and why we call it factory-direct pricing.