Winix AM90 Review: Smart 4-Stage Air Cleaning

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Winix built its reputation on the 5500-2, a purifier that has spent years as a Reddit favorite for its 4-stage filtration and washable carbon filter. The AM90 is what happens when Winix takes that proven formula and adds WiFi, an app, and voice control. It is the brand's answer to the smart-purifier era, and it pairs naturally with the picks in our best smart air purifiers guide.

We went through the specs, ran the numbers against its rivals, and weighed what the smart upgrade actually buys you over the cheaper 5500-2. Here is our full review.

The Basics: What You Get for $200

The Winix AM90 is a smart air purifier with a 4-stage filtration system. Air passes through a washable mesh pre-filter, a washable activated carbon filter, a True HEPA filter, and finally Winix's PlasmaWave ionization stage.

It covers rooms up to 360 sq ft, which suits medium-to-large bedrooms, family rooms, and home offices. The tower-style unit measures 14.9 by 7.8 by 23.6 inches and weighs about 16.5 pounds, making it taller and heavier than most of its rivals.

The smart features are the headline. You get WiFi, the Winix Smart app, Alexa and Google Assistant support, an auto mode driven by a built-in air quality sensor, a sleep mode that activates automatically in the dark, and a timer. An air quality indicator on the unit shows status at a glance.

Winix AM90 Air Cleaning Performance

The AM90 posts CADR ratings of 240 CFM for dust, 233 CFM for smoke, and 230 CFM for pollen. If you want to know why CADR matters more than any feature list, see our explainer on what CADR means.

Here is how it compares to the smart and value purifiers we cross-shop it with:

At 360 sq ft, the AM90 delivers about two air changes per hour. For allergy and asthma households, where we prefer four changes per hour, the real-world sweet spot is closer to 180 sq ft, which is a comfortable bedroom or office. Its CADR is competitive with the 5500-2 and Coway 200M, though the Levoit Core 400S edges it on raw output.

The True HEPA filter captures 99.97% of particles at 0.3 microns, covering dust, pollen, dander, and fine smoke. That dependable filtration, plus the auto mode and quiet sleep behavior, is why the AM90 earns a spot in our best air purifiers for bedrooms picks.

The 4-Stage Filtration System

Where the AM90 stands out is filtration depth. Most purifiers near this price use 3 stages; the AM90 uses 4, and two of them are washable:

Stage 1: Washable Mesh Pre-Filter. Catches hair, lint, and large dust. Reusable, so you vacuum or rinse it rather than replacing it.

Stage 2: Washable Activated Carbon Filter. This is the AM90's signature cost-saver. The carbon filter that absorbs odors, smoke, and VOCs is washable and reusable. Most competitors use a disposable carbon filter you replace every few months; the AM90 lets you rinse it instead. For the distinction between particle and gas filtration, see carbon filter vs HEPA.

Stage 3: True HEPA. The main filter, capturing 99.97% of particles at 0.3 microns. This is the workhorse for allergens and fine particulate, and the only filter you replace on a schedule, about once a year for roughly $40.

Stage 4: PlasmaWave. Winix's ionization stage releases charged ions to help break down pollutants and odors. It produces only trace ozone within safety limits, and you can switch it off if you prefer pure mechanical filtration.

Because the carbon and pre-filter are both washable, the AM90 earns a place in our best air purifiers with washable filters guide. The only recurring cost is the annual HEPA filter.

Smart Features and the Winix App

The smart layer is what separates the AM90 from the cheaper 5500-2:

Auto mode and air quality sensor. A built-in sensor reads particle levels and drives auto mode, ramping the fan up when air quality drops and easing off when it clears. An indicator on the unit shows real-time status.

Winix Smart app. The app lets you control the unit, monitor air quality, set schedules, and track filter life from anywhere. It can be a little slow to connect at times, which is the most common owner complaint, but it is functional once paired.

Voice control. Alexa and Google Assistant support means hands-free operation and smart-home automation.

Smart sleep mode. A light sensor detects when the room goes dark and automatically drops the fan to its quietest setting, then resumes when the lights come back on. It is a small touch that works well in bedrooms.

If smart control is your main driver, weigh the AM90 against the rest of our best smart air purifiers lineup.

Noise Levels: Fine, Not Class-Leading

On its lowest setting the AM90 runs at about 28 dB, a little louder than the sub-25 dB sleep modes on the Levoit Core 400S and Coway 200M, but still quiet, roughly a soft library level. The smart sleep mode helps by automatically dropping to that lowest speed when the room is dark.

On its higher fan speeds it climbs into the mid-50s dB on high, which is noticeable, similar to a quiet conversation. In auto mode it spends most of its time at lower speeds and only ramps up when the sensor catches a spike.

For most bedrooms the 28 dB low setting is perfectly livable. If you are a light sleeper who needs near-silence, a sub-25 dB unit edges it out, but the gap is small in practice.

Build Quality and Design

The AM90 uses a tall, tower-style design in white with a curved front panel and top-mounted controls. Air pulls in through the front and exhausts out the top. It is a clean, unobtrusive look, though at 16.5 pounds and nearly 24 inches tall it is the heaviest and tallest of the purifiers in this comparison.

Build quality is solid and typical of Winix, which has a long track record in air cleaning. The controls are responsive, the air quality indicator is easy to read, and the washable filters are simple to access and reinstall.

The size is the main physical tradeoff. It has a larger presence than a compact Coway 200M or a slim Levoit Vital 200S, so factor in the footprint if space is tight.

Filter Costs and Total Cost of Ownership

The washable carbon filter makes the AM90 cheap to live with:

The only filter you replace on a schedule is the True HEPA, at about $40 a year. The carbon and pre-filters are washable, so there is no recurring carbon cost, which is a genuine advantage over purifiers that use disposable carbon every few months. At 65 watts maximum draw it is a little less efficient than some rivals, costing roughly $22 a year to run with regular use.

The washable carbon filter is the AM90's standout value argument: lower lifetime cost than most smart purifiers in its class. For more budget options, see our best air purifiers for bedrooms picks.

Where the AM90 Falls Short

A few honest weaknesses to weigh:

Louder on low than rivals. At 28 dB it is fine, but the quietest competitors sit a few decibels lower.

Bigger and heavier. It is the tallest and heaviest unit in this comparison, so it takes up more space.

App can be slow. The Winix Smart app sometimes lags or is slow to connect, though it works once paired.

PlasmaWave produces trace ozone. It is within safety limits and can be turned off, but ozone-sensitive users may prefer to leave it off.

Coverage rating is optimistic. The 360 sq ft figure assumes two changes per hour; judge it by the stricter four-changes standard for allergies.

Who Should Buy the Winix AM90

Buy the AM90 if:

• You want smart features plus a washable carbon filter to lower running costs
• You like deep 4-stage filtration with True HEPA and PlasmaWave
• You want auto mode and a smart sleep mode for a bedroom (see best air purifiers for bedrooms)
• You have allergies and want dependable True HEPA (see best air purifiers for allergies)
• You prefer washable filters to cut waste and cost (see best air purifiers with washable filters)
• Your room is a medium-to-large bedroom, office, or family room

Skip the AM90 if:

• You want the quietest possible low setting (the Levoit Core 400S is quieter)
• You need to cover a larger room over 400 sq ft (step up to the Levoit Core 400S)
• Floor space is tight and a tall, heavy tower is a problem
• You do not need smart features and want the lowest price (the Winix 5500-2 is the value pick)

How It Compares to Key Competitors

Winix 5500-2 (~$180): The non-smart sibling. Same 4-stage filtration, washable carbon, and similar CADR, for less money, but no WiFi, app, or auto mode. The AM90 wins on smart features; the 5500-2 wins on price for identical cleaning. Read our Winix 5500-2 review.

Levoit Core 400S (~$190): Higher CADR, quieter on low, a laser PM2.5 sensor, and a larger 403 sq ft coverage. The AM90 counters with 4-stage filtration and a washable carbon filter the Levoit lacks. The Core 400S wins on output and sensor precision; the AM90 wins on washable carbon and lifetime cost. Read our Levoit Core 400S review.

Coway Airmega 200M (~$160): A cheaper non-smart unit with 4-stage filtration and a quiet 24.4 dB low setting. It has no app, but it is quieter and cheaper. The AM90 adds smart features and washable carbon. See our Coway Airmega 200M review.

For our full decision framework, see how to choose an air purifier.

The Bottom Line

The Winix AM90 takes the proven 5500-2 formula and makes it smart. You get 4-stage filtration with True HEPA, a washable carbon filter, and PlasmaWave, plus WiFi, an app, voice control, and an auto mode that reacts to a built-in sensor. The washable carbon and pre-filter mean the only recurring cost is an annual HEPA filter, which keeps lifetime cost low.

It is not perfect. It is a little louder on low than the quietest rivals, it is the biggest and heaviest unit in its class, and the app can be slow. But for a buyer who wants smart features without committing to disposable carbon filters forever, it hits a sweet spot few competitors match.

We rate the Winix AM90 an 8.8 out of 10. It scores well for filtration depth, smart features, and lifetime value, losing a little on noise and size. If you want a smart purifier with a washable carbon filter, it is one of the best you can buy.

See where it ranks in our best air purifiers, best smart air purifiers, and best air purifiers for bedrooms guides.

Check Winix AM90 Price on Amazon