Air passes a washable fine mesh pre-filter, an AOC carbon stage for odors, then a True HEPA filter that captures 99.99% of airborne allergens. Each stage handles a different job, so particles and smells are addressed together.
The 5520 is AHAM verified for rooms up to 392 sq ft, with CADR of 252 dust, 247 pollen and 253 smoke and 4.8 air changes per hour. You can compare those figures directly against other units.
Dual smart sensors read air quality and adjust fan speed without input, shown on a three-color LED indicator. Cooking smoke, pet dander or an opened window changes the output on its own while you do nothing.
WiFi works with the Winix Smart App for status checks and scheduling from your phone, including from away from home. The unit runs fully without the app, though some owners report mixed results on certain networks.

The True HEPA filter captures 99.99% of airborne allergens, and the 5520 is AHAM verified for rooms up to 392 sq ft with a dust CADR of 252, numbers you can compare directly against other units.

The AOC carbon filter works on cooking, pet and household odors rather than only trapping particles, so a room smells fresher as well as looking cleaner. Filter life is rated at about 12 months.

Dual smart sensors read the air and change fan speed on their own, shown on a three-color LED indicator. You set it once and the unit responds to cooking, pets or an opened window without input.

Automated Sleep Mode lowers output and settles the unit when the room darkens, and ultra-quiet operation at low speed makes overnight use realistic instead of something you switch off.

WiFi compatibility with the Winix Smart App lets you check status and adjust settings from your phone, even from away. Note that some owners report mixed results connecting to certain home networks.

The fine mesh pre-filter catches hair and large debris and rinses clean, which protects the True HEPA and carbon stages behind it and helps stretch the 12-month replacement cycle for both.

Two or three dogs or cats generate dander and odor daily, and the True HEPA plus carbon stages handle both. Auto Mode speeds up after a walk without anyone touching a control.

Sleep Mode dims and settles the unit when the room darkens, and low speeds stay quieter than an air conditioner. That makes overnight running realistic instead of something you switch off at bedtime.

Frying and simmering leave smells that linger well past the meal. Run the 5520 near the kitchen doorway so the carbon stage works on odors rather than only trapping airborne particles.

In a family room the unit reacts to activity on its own, with the three-color indicator telling anyone walking past what the air currently reads. Five fan speeds cover quiet evenings and busy afternoons.

Pollen drifting in through an open window registers quickly on the sensors, and the AHAM-verified 392 sq ft coverage with a 247 pollen CADR clears a bedroom or sitting room effectively.

A single tower handles one large open room without permanent installation or wiring. Owners who move often can simply carry it, and the washable pre-filter keeps recurring costs to two filters a year.
