LEVOIT Air Purifiers for Large Home Bedroom 166m², CADR 400m³/h, Alexa Enabled, Filter with PM2.5 Intelligent Air Quality Sensor, Auto Mode,, Removes Pollen Allergy Dust Smoke Pet

The Levoit Core 400S covers up to 166 m² with a CADR of 400 m³/h. Roughly double the Core 300's output. 38,000+ reviews at 4.6 stars, 400+ bought last month. It's the step-up for people who want app control and a real air quality sensor without spending Dyson money.

How big a room can it handle?

166 m² is the single-pass figure for a closed room. In practice, an open-plan kitchen-living room of around 80 m² will get two air changes per hour, which is what most guidelines recommend. Smaller than that and it'll cycle air faster than you need.

For rooms under 80 m², the Core 300 is probably enough and costs less. Our best air purifier for large rooms guide covers what CADR you actually need for different room sizes.

The PM2.5 sensor

This is the main reason to pick the 400S over the Core 300. The AirSight Plus laser sensor reads PM2.5 levels in real time and shows them on the display and in the VeSync app. Auto mode adjusts fan speed based on what it reads. Cook a stir fry, the fan ramps up. Air clears, it drops back down.

The Core 300 has none of this. You set it manually and hope for the best. Our how do air purifiers work article explains the sensor tech if you want the detail.

Noise

Quiet on low. On high, you'll hear it. The 400S pushes more air than the 300, so the fan works harder at full speed. Sleep mode sits around 24 dB, which is fine for a bedroom. We compared noise levels across several models in our quiet air purifier for sleeping roundup.

Filter and running costs

Same three-stage H13 HEPA setup as the rest of the Levoit range. Pre-filter, HEPA, activated carbon. Replacement filter is the Core 400S-RF, around £30-£40, and Levoit say every 12 months. If you run it on auto most of the time you might stretch that, since it won't always be on full power.

The unit pulls about 50W at max. Our air purifier electricity cost guide has the maths on what that costs per month at current UK rates.

App and Alexa

VeSync app gives you scheduling, fan speed control, filter life tracking, and air quality readings from anywhere. Works with Alexa and Google Home. Handy for turning it on from another room, not much else.

How it compares to Dyson

Fraction of the price. Dyson purifiers double as fans, look nicer, and have fancier apps. But the Core 400S matches or beats most Dyson models on CADR and filtration. If you just want clean air and don't care about the bladeless fan thing, save yourself the money. Our Dyson vs Levoit comparison has the full numbers.

For hay fever specifically, our best air purifier for allergies guide puts this alongside the Philips 3000i and Winix Zero-S.