My air purifier is making noise and producing less airflow — what's wrong?

The filters are likely dirty and may need to be replaced. High amounts of contaminants can block the pores in the filter and prevent air from moving through it. The solution is to replace the filters. (Page 4)

From the official Honeywell HPA090 Air Purifier manual, page 4

Have a follow-up question?

Answers from the official manual.

Common questions