Changing your air filter is the single easiest thing you can do to maintain your HVAC system — and most people do it far less often than they should.
General Guidelines
- 1-inch filters (standard): every 1–2 months
- 2-inch filters: every 3 months
- 4–5 inch media filters: every 6–12 months
- HEPA filters: per manufacturer instructions (usually 6–12 months)
Change More Often If You Have...
- Pets (pet hair and dander clog filters faster)
- Allergies or asthma
- More than 2 people in the home
- High dust environment or active construction nearby
What Happens When You Don't Change It
A clogged filter restricts airflow, forcing the blower motor to work harder. This increases energy bills, stresses the compressor, and can cause the system to freeze up in summer or overheat in winter. A $10 filter is much cheaper than a $1,500 compressor repair.