WINIX Zero-S Air Purifier for Bedroom HOM, CADR 410m³/h, 100m², Active Carbon & HEPA Filters Pollen Allergies Dust Smoke Odors, Air Cleaner Smart Sensor, Sleep Auto Mode

The Winix Zero-S has a CADR of 410 m³/h and covers rooms up to 100 m². Certified by both Allergy UK and AHAM, which is more than most competitors bother with. Winix have been making air purifiers since 1973, longer than Levoit or Shark have existed.

PlasmaWave

Winix's proprietary tech. It generates hydroxyls that break down odours, bacteria, and chemical vapours at a molecular level. This runs alongside the physical HEPA filtration rather than replacing it. Some people prefer purely mechanical filtration with no plasma or ioniser element. The Winix does both.

Our how do air purifiers work article explains the different technologies and what each one actually does.

Filtration

Three stages: mesh pre-filter for large particles, active carbon pellet filter for smoke and odours, and HEPA that captures 99.999% of particles down to 0.1 microns. The carbon pellet filter is worth noting. Most competitors use a thin carbon sheet. Pellets have more surface area and last longer for odour removal. Useful if you're dealing with cooking smells or cigarette smoke. Our air purifier for cooking smells article has more on that.

Sleep and auto mode

27.4 dB on sleep mode with all lights dimmed. Not quite as quiet as the COWAY Airmega at 20 dB, but quieter than most. Auto mode uses the built-in particle sensor to adjust speed based on air quality. No app or WiFi, same as the COWAY. You control it from the panel on top. Our quiet air purifier for sleeping roundup has the noise comparison.

How it compares

Similar CADR to the Levoit Core 400S (410 vs 400 m³/h) and similar room coverage. The Winix adds PlasmaWave and the Allergy UK certification. The Levoit adds app control and Alexa. Different trade-offs depending on what you care about.

Against the Philips 3000i, the Winix is cheaper with comparable filtration. The Philips has a quieter sleep mode and a nicer app. Our best air purifier UK roundup has the full comparison across all brands.

Who it's for

Allergy sufferers who want something tested and certified by an actual allergy organisation, not just marketed at them. The carbon pellet filter also makes it better than average for smoke and kitchen odours. If you want app control, this isn't it. If you want proven filtration from a company that's been doing it for 50 years, it's a strong choice.

Our best air purifier for allergies guide has the allergy-focused comparison.