Samsung Air Purifier AX90 - The AX7500K with Three-Stage Filtration

The Samsung Air Purifier AX90 (model AX90T7080WD, marketed as the AX7500K) is a freestanding whole-room purifier built for large spaces up to 90 square metres. It uses a three-stage filtration system with a true HEPA filter rated at 99.97% particle capture efficiency. The unit integrates with Samsung SmartThings for app control and Bixby for voice commands. It earned Sensitive Choice certification in Australia, a mark given to asthma and allergy-friendly products.

Three-Stage Filtration System

The AX90 handles air purification in three passes. Each stage targets a different type of pollutant.

First, a washable pre-filter traps large particles like pet hair, dust, and lint. This filter slides out from the front panel for easy cleaning under running water. Washing it monthly extends the lifespan of the HEPA filter underneath.

Second, an activated carbon deodorization filter absorbs odors from cooking, pets, and volatile organic compounds. This filter is not washable and needs replacement roughly every six months depending on usage.

Third, the true HEPA filter captures particles down to 0.3 microns with 99.97% efficiency. This includes pollen, mold spores, dust mite waste, and fine particulate matter (PM2.5). Samsung displays a filter life indicator on the unit so you know when replacement is due.

Smart Sensor and Auto Mode

The AX90 includes a built-in particle sensor that reads air quality in real time. The sensor measures fine dust concentration (PM2.5) and displays a color-coded indicator: blue for clean, yellow for moderate, and red for polluted.

In auto mode, the unit adjusts fan speed based on sensor readings without any manual input. When pollution spikes after cooking or opening a dusty window, the fan ramps up. Once the air clears, it returns to a low, quiet setting. This keeps power consumption low during clean periods.

SmartThings Integration

The AX90 connects to SmartThings via Wi-Fi. Through the SmartThings app you can see live air quality readings, switch between sleep, low, medium, and turbo fan modes, set schedules, and receive filter replacement alerts. The app also shows historical air quality data so you can see patterns over time.

Bixby voice commands work through Samsung devices. You can ask Bixby to turn the unit on, switch modes, or report current air quality. Amazon Alexa and Google Assistant are not directly supported on this model.

SmartThings also integrates with Home Assistant, which lets you incorporate the AX90 into broader automations. You could automate the purifier to turn on when your robot vacuum finishes a cleaning cycle, for instance.

Design and Coverage

The AX90 uses a cylindrical tower design with a 3-way airflow system. Air is drawn in through the bottom and sides, passes through all three filters, and exhausts upward and outward through three vents near the top. This design circulates clean air more evenly than front-facing units that only push air in one direction.

The unit covers up to 90 sq m, making it suited for large living rooms, open-plan kitchen-dining areas, or commercial spaces like small offices. The slim profile (14.2 x 11.2 inches footprint) means it fits in corners without dominating the room.

Use Cases

The AX90 works best in these scenarios:

• Homes with allergy or asthma sufferers who need continuous HEPA filtration
• Households with pets that generate dander and odors
• Urban apartments exposed to outdoor PM2.5 pollution
• Spaces with cooking odors that activated carbon can absorb

The auto mode handles most situations without manual adjustment. Set it and leave it running. The home environment stays monitored around the clock.

Setup and Getting Started

Setup takes under ten minutes. Place the unit in a central location at least 30 cm from walls to allow airflow on all sides. Plug it in, download the SmartThings app, and add the AX90 as a new device. The app walks through Wi-Fi configuration. Once connected, set your preferred default mode.

For the first run, let it operate on turbo mode for 30 minutes to purge the filters of any manufacturing residue. Then switch to auto mode for normal operation.

Specifications

Final Assessment

The Samsung AX90 delivers solid three-stage filtration in a well-built cylindrical unit. The washable pre-filter cuts long-term running costs. SmartThings integration works reliably and the auto mode reduces the need for manual operation. The Sensitive Choice certification gives confidence for households managing asthma or allergies.

The main limitation is voice assistant support - Bixby only, with no Alexa or Google Assistant. If your household uses Amazon or Google voice control, this model will not integrate with those systems.

For Samsung SmartThings households where air quality matters, the AX90 is a practical choice that runs quietly, covers large rooms, and notifies you when maintenance is due.