For the Coway 1018F Classic, the recommended filter cleaning / replacement frequency is as follows:

FILTER CLEANING / REPLACEMENT FREQUENCY
Pre-Filter Clean and wash every 2-4 weeks
Deodorisation Filter Replace every 12 months
HEPA Filter Replace every 12 months


*Based on 24 hour (1 day) use at low air speed

*The filter replacement cycle is the recommended cycle and may vary depending on usage environment