Winix AM90 Review: Wi-Fi Purifier for 370 sq ft, With a Catch

What the Winix AM90 is

The AM90 is a tower purifier with a four-stage filter: a washable pre-filter, an activated carbon filter, a True HEPA filter and PlasmaWave, Winix's ionizer-type feature. It has five fan speeds, an automatic sleep mode, and Wi-Fi control through the Winix Smart app and Alexa, according to Winix's product page.

Winix AM90 AHAM figures

The AHAM Verifide directory lists the AM90 at 241 cfm for smoke, 238 for dust and 245 for pollen, with a suggested room size of 373 sq ft and an integrated energy factor of 4.6. Winix's own product page still prints older figures (233 dust, 240 pollen, 230 smoke), but agrees on the 373 sq ft room size; we use AHAM's directory as the source of record.

Air changes per hour from 241 cfm smoke CADR, 8 ft ceilings.

Room	Floor area	Air changes an hour
Bedroom, 13 x 15 ft	195 sq ft	9.3
Living room, 15 x 20 ft	300 sq ft	6.0
AHAM room size	373 sq ft	4.8
Open plan, 20 x 25 ft	500 sq ft	3.6

Winix's "up to 1,790 sq ft" assumes one air change an hour. For a sense of what your own room needs, use the sizing calculator.

The filter cost problem

Winix gives the AM90's True HEPA filter a 12-month life and its activated carbon filter 3 months, and the manual says the carbon filter cannot be washed. The replacement is Filter A (115115), which Winix lists at $109.99 on its store, with PetGuard, SmokeGuard and AllergenGuard versions at $119.99. Genuine Winix Filter A is also sold on Amazon.

Compare that with the 5510, whose AOC carbon panel lasts about 12 months. If odor control matters to you, the AM90's carbon needs four changes a year to keep working; if it does not, you can run the AM90 past three months with spent carbon and the HEPA filter still does the particle work, but then you are paying for a feature you are not using.

PlasmaWave and ozone

Like other Winix models, the AM90 includes PlasmaWave. Winix says it does not produce harmful ozone, and Winix models with PlasmaWave are certified by the California Air Resources Board as electronic air cleaners, which must stay at or below 0.050 ppm of ozone. We did not find the AM90 by name on CARB's certified list, so check the label on the unit if that matters to you. The 5510's manual gives PlasmaWave its own on/off button; check the AM90's control panel for the same if you want it off. Our ionizer guide explains why some people switch it off.

Noise and size

Winix quotes a minimum of 27 dB, a few decibels higher than the 5510's 23.5 dB low setting. The AM90 is 23.6 in tall and 15.8 lb, and its slim 7.8 in depth suits a spot against a wall or in a corner.

What the AM90 costs to run for three years

AHAM's directory estimates the AM90 uses 303 kWh a year; at 17.2 cents per kWh, EIA's 2025 average US residential price, that is about $52 a year. Filters are the bigger and less predictable cost because the HEPA and carbon filters run on different clocks.

Three-year cost at Winix's list prices, AHAM's annual energy estimate and 17.2 cents per kWh. Our arithmetic; filters are a minimum.

Item	Cost
Purifier (Winix list price)	$299.99
Filter A, at least one a year for 3 years (Winix store)	$329.97 or more
Electricity, 3 years	$156
Total	$786 or more

Before you buy a replacement pack, check what it contains: the HEPA filter lasts a year but the carbon filter is rated for three months, so a year of odor control needs four carbon filters. A pack that holds one HEPA and one carbon filter covers only a quarter of the year's carbon.

Setup and upkeep

Winix's manuals for its PlasmaWave towers ask you to vacuum or rinse the pre-filter regularly and to let it dry fully before refitting it. Keep the AM90's intake and the outlet on top clear, give it a few inches of space from walls, and reset the filter indicator after each change so the reminder stays accurate. The cleaning guide covers the general routine.

Winix AM90 vs the alternatives

AHAM Verifide figures, read November 3, 2026. Filter life from each maker.

Model	Smoke CADR	Room size	Carbon life
Winix AM90	241 cfm	373 sq ft	3 months
Winix 5510	253 cfm	392 sq ft	About 12 months
Levoit Vital 200S-P	250 cfm	388 sq ft	Combined filter
Levoit Core 400S-P	234 cfm	363 sq ft	Combined filter

Who should buy the Winix AM90

• Buy it if you want a slim Wi-Fi tower for a 300 to 370 sq ft room and it is available at a good price.
• Skip it if odor control matters; the 5510's carbon lasts about four times longer.
• Skip it if Amazon is still out of stock and the 5510 is not; the 5510 is the stronger, cheaper-to-run machine.
• Skip it for a big room; see our large room picks.
• Buy it over a cylinder if floor space is tight: at 7.8 in deep it fits beside a bed or desk where a round unit would block a path.

For more mid-size options, see the best air purifiers.