An air purifier is only as good as its maintenance. Neglected filters don't just work poorly—they can recirculate particles and even grow mold. Here's how to keep your purifier in top shape.
Filter Replacement Schedule
HEPA Filters
Replace every 6-12 months depending on air quality and usage. Signs it's time:
- Visible discoloration (turning gray/brown)
- Reduced airflow from the purifier
- Manufacturer's indicator light (if equipped)
- Odors coming from the purifier
Activated Carbon Filters
Replace every 3-6 months. Carbon becomes saturated and stops absorbing. Signs:
- Odors returning that the purifier used to control
- No improvement in smell when running
- Manufacturer's recommended timeline reached
Pre-Filters
Clean or replace every 1-3 months. These catch large particles to protect the HEPA filter:
- Many are washable—check your manual
- Vacuum gently to remove accumulated debris
- Replace if damaged or permanently discolored
Regular Cleaning Tasks
Weekly
- Wipe exterior with a damp cloth
- Check air intake/outlet for blockages
Monthly
- Clean or vacuum pre-filter
- Check for unusual noises or smells
- Wipe sensors if your unit has them (dust affects readings)
Every 3-6 Months
- Deep clean the exterior and vents
- Replace carbon filter (if applicable)
- Inspect HEPA filter condition
Can You Wash HEPA Filters?
Generally, no. True HEPA filters are made of densely packed fibers that water damages. Washing:
- Damages the fiber structure
- Can cause mold growth
- Voids most warranties
- Reduces filtration efficiency
Some filters marketed as "washable" aren't true HEPA. If your filter is labeled washable, follow the manufacturer's specific instructions. But understand that "washable HEPA" is usually a compromise on filtration quality.
What You Can Do
- Gently vacuum the outside of HEPA filters to extend life slightly
- Don't tap or shake them indoors (releases captured particles)
- Replace when indicated—don't try to stretch it too far
Troubleshooting Common Issues
Reduced Airflow
- Check for blocked vents
- Clean or replace pre-filter
- Replace HEPA filter if overdue
- Ensure nothing is blocking intake/outlet
Strange Odors
- Replace carbon filter
- Check HEPA filter for mold (especially in humid environments)
- Clean sensor chambers if equipped
- In rare cases, the motor may need service
Unusual Noise
- Check for debris in intake
- Ensure filter is properly seated
- Place on flat, stable surface
- Motor issues may require service
Sensor Inaccuracy
- Clean sensor opening with soft brush or compressed air
- Dust buildup causes false readings
- Some sensors degrade over time
Storage
If storing your purifier for extended periods:
- Clean all filters and the unit
- Ensure filters are completely dry
- Store in a dry location
- Remove any batteries if applicable
- Consider replacing filters when you resume use