Air Purifiers Review
Xiaomi Smart Air Purifier 4 (AC-M16-SC) Review: Strong Value
Our verdict
The Xiaomi Smart Air Purifier 4 (AC-M16-SC) cleans a bedroom nearly as fast as the best purifier here, with a good app and sensor, at a much lower price than Dyson.
Buy it if
- Flat-owners who want high CADR and a decent app without paying Dyson prices
- Bedrooms and living rooms up to about 300 sq ft
- Homes using the Xiaomi Home ecosystem
Skip it if
- You want a quiet turbo mode
- You want a strong on-site service network in tier-2 cities
What we like
- 400 m3/h particle CADR, second fastest in our tests
- Laser particle, temperature and humidity sensing
- OLED touch display and Xiaomi Home app
- Works with Google Assistant and Alexa
- Reasonable filter life of about 12 months, per Xiaomi
What we don’t
- Loud at top speed, up to 64 dB(A) per Xiaomi
- Filter described as True HEPA with no H-grade in India
- No gas (VOC) sensor
- Service and spares depend on Xiaomi's thinner network
Score breakdown
- Performance
- 8.4
- Features
- 7.9
- Noise
- 6.8
- Energy efficiency
- 7.4
- Build quality
- 7.3
- Ease of use
- 8.2
- Value for money
- 8.3
- After-sales service
- 6.4
The Xiaomi Smart Air Purifier 4 is the sensible buy for anyone who wants strong clean-up for a Delhi winter without paying for a premium brand. It is quick, the app is good and the display tells you what is happening. The trade-offs are noise at top speed and a thinner service network than Philips or Dyson.
How fast does it clean a bedroom?
In the 180 sq ft test room it took 18 minutes to bring PM2.5 from about 300 to under 35 ug/m3, two minutes behind the Boon Airvana. That matches the 400 m3/h particle CADR Xiaomi publishes. Xiaomi quotes 28 to 48 m2 coverage on its global pages, but we would use the lower end for severe smog.
How loud is it on Sleep and on turbo?
Quiet where it counts: about 34 dB on Sleep at 1 metre. On top speed we measured around 62 dB, in line with Xiaomi’s 64 dB(A) maximum, and that is loud enough to talk over. Most people run Auto, which settles at a middle speed once the room is clean.
Is the sensor and app any good?
The laser particle sensor tracked our reference monitor within about 12 percent across 40 to 400 ug/m3. It also reads temperature and humidity, though there is no VOC sensor, so cooking fumes and fresh paint will not trigger it. The Xiaomi Home app handles schedules and shows a clean history graph. Pairing took a few minutes on 2.4 GHz Wi-Fi, which many Indian routers still default to.
What are the filters and running costs?
Xiaomi quotes a 12-month filter life, depending on usage. In a Delhi November that is optimistic, and we would plan on a change every 8 to 10 months in a polluted city. We did not find an official Indian replacement price at review time, so we have not computed a yearly cost. Wall power on top speed measured about 36 W.
What about service and long-term use?
Owners praise the speed and the display, and complain about fan noise and getting service outside metros. Xiaomi sells spare filters online, but waiting times differ by city. Buy from a seller you trust and keep the invoice.
Who should look elsewhere?
If noise matters, the Levoit Core 300S is quieter at every speed but suits only small rooms; the Dyson is barely quieter at top speed and slower. If you want gas sensing and a bigger smart-home feature set, the Boon Airvana is better.
Test results
| PM2.5 clean-up, 180 sq ft bedroom How we test this : PM2.5 clean-up, 180 sq ft bedroom | 18 min |
|---|---|
| Noise on lowest or Sleep setting How we test this : Noise on lowest or Sleep setting | 34 dB Sleep mode |
| Noise at top speed How we test this : Noise at top speed | 62 dB |
| Power draw at top speed How we test this : Power draw at top speed | 36 W |
| PM2.5 reading vs reference monitor How we test this : PM2.5 reading vs reference monitor | 12 % Across 40 to 400 ug/m3 |
Measured on the unit we tested.
How we tested
We bought a unit and ran it for five weeks in a 180 sq ft bedroom with outdoor AQI between 270 and 450. We timed PM2.5 clean-up from about 300 to under 35 ug/m3 after burning incense, measured noise at 1 m on Sleep and top speed, logged wall power and checked the sensor against a handheld reference monitor.
We bought this unit at retail price.
How does the Xiaomi Smart Air Purifier 4 (AC-M16-SC) compare?
-
Boon Airvana Smart Air Purifier A 9.1
The Boon Airvana cleared our 180 sq ft bedroom two minutes faster, 16 against 18, is quieter and adds gas sensing and a bigger smart-home feature set. The Xiaomi draws less power at top speed.
Full comparison : Xiaomi Smart Air Purifier 4 (AC-M16-SC) vs Boon Airvana Smart Air Purifier -
Dyson Purifier Cool PC1 (TP11) B+ 8.1
The Xiaomi cleared our bedroom faster, in 18 minutes against the Dyson's 23, at a much lower price. The Dyson is better built and has wider service; top-speed noise is similar (62 vs 61 dB).
-
Levoit Core 300S Smart Air Purifier B− 7.3
The Levoit is much quieter, about 27 dB on low and 51 dB at top speed, but suits only small rooms: it needed 27 minutes in our 180 sq ft bedroom against the Xiaomi's 18.
-
Philips Series 2000i Air Purifier AC2958/63 B− 7.4
The Philips costs more and cleared our bedroom three minutes slower, in 21 minutes against 18, but has a much wider service network and is slightly quieter at top speed.
Full comparison : Xiaomi Smart Air Purifier 4 (AC-M16-SC) vs Philips Series 2000i Air Purifier AC2958/63
Key specs
| Particle CADR | 400 m3/h |
|---|---|
| Formaldehyde CADR | 150 m3/h (Xiaomi global page) |
| Effective coverage (Xiaomi) | 28-48 m2 (global page) |
| Filtration | Pre-filter, high-efficiency filter, activated carbon |
| Sensors | Laser particle, temperature, humidity |
| Display | OLED touch |
| Noise (Xiaomi) | Up to 64 dB(A) |
| Smart features | Xiaomi Home app, Google Assistant, Alexa |
| Filter replacement | About 12 months, usage dependent (Xiaomi) |
Questions buyers ask
How good is the Xiaomi Smart Air Purifier 4 for Indian homes?
The Xiaomi Smart Air Purifier 4 is very good for rooms up to about 300 sq ft. It cut PM2.5 from about 300 to under 35 ug/m3 in 18 minutes in a 180 sq ft bedroom, and its 400 m3/h CADR is among the highest in this price band.
Is the Xiaomi Air Purifier 4 loud?
At top speed, yes. Xiaomi lists up to 64 dB(A) and we measured about 62 dB at 1 metre. On Sleep it measured about 34 dB, which most people ignore at night.
Does the Xiaomi Air Purifier 4 have Alexa and Google Assistant?
Yes. Xiaomi lists compatibility with both Google Assistant and Amazon Alexa through the Xiaomi Home app, along with scheduling and live PM2.5 readouts.
Also consider
-
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The Boon Airvana is the best home air purifier we tested for Indian winters: 380 m3/h CADR, two H13 HEPA filters, eight-parameter sensing and full app and smart-home control.
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Levoit Core 300S Review: Compact Smart Purifier
The Levoit Core 300S is a compact, quiet smart purifier with app and Alexa control and a 2-year warranty, but its CADR suits only small Indian bedrooms.