The Honeywell Allergen Plus HEPA Air Purifier (HPA5300B) quietly delivers cleaner, fresher air to extra-large rooms up to 500 sq ft. Like many HEPA filter air purifiers, it relies on high-efficiency filtration, and this large air purifier for dorm rooms is ideal for homes with pets or even an office. It uses an Air Quality Sensor to monitor conditions and display real-time cleaning levels, making it an excellent air purifier for pets. Whether you seek allergy relief, smoke reduction, or simply better bedroom air, Auto Mode, 2/4/8-hour shut-off timers, and a night-time dimmer let you tailor performance. Three genuine “R” HEPA filters (replace annually) capture up to 99.97%* of microscopic allergens such as dust, pollen, pet dander, and wildfire smoke, while the included “A” pre-filter (replace every three months) traps larger particles like hair or lint and helps reduce common household odors from paints, cleaners, and candles. Disclaimers:*From the air that passes through the filter, 0.3 microns and larger. **Based on third-party independent CADR testing for the smoke CADR value when operated at the highest setting. Air circulation depends on room size and configuration; not all air will pass through the filter