Rank #6 in Best Air Quality Monitor 2026: Fewer Numbers, Better Sensors
Temtop C1 CO2 Monitor, 400-5000ppm, Temperature and Humidity
Price and rating as shown on Amazon when we collected them. Both change.
The Temtop C1 is the best-rated cheap CO2 monitor here: 4.4 stars from 717 ratings, 70 per cent of them five-star and only 7 per cent one-star, for £42.49. It measures CO2 from 400 to 5000ppm plus temperature and humidity, with an audible alarm and a detachable stand.
It sits sixth because of what it cannot do — no particles, no VOCs, no app — and because its own listing calls the sensor photoelectric in one place and photoacoustic in another, which is a copy error you should know about before buying.
How those 717 ratings break down
An average hides its own shape. This is the spread behind the 4.4 stars.
Specification
Exactly as published on the Amazon listing, field for field.
| What it measures | CO2, temperature, humidity |
|---|---|
| CO2 range | 400 to 5000 ppm |
| Sensor as listed | Photoelectric in the spec, photoacoustic in the bullets |
| Ratings | 4.4 from 717 |
| Power | Battery powered |
| Price | £42.49 |
What buyers actually say
Quoted from customer reviews on Amazon
Verified purchase“Very simple and efficient monitor for quick checking of air quality.”
Verified purchase“Is a great addition to any living room when having guest over our living room becomes stuffy really quick so helps avoid headaches”
What it is up against
The rivals it was ranked against in Best Air Quality Monitor 2026: Fewer Numbers, Better Sensors.
Rank #1
Aranet4 Home Wireless Indoor Air Quality Sensor, NDIR CO2 Monitor
£189.00
Rank #2
Temtop M2000 2nd Air Quality Monitor, PM2.5 PM10 CO2 HCHO
£158.64
Rank #3
Temtop Air Quality Monitor LKC1000S+ 2nd, PM2.5 PM10 HCHO TVOC
£129.99
Rank #4
Airthings 2960 View Plus, Radon and Air Quality Monitor with PM2.5
£166.99
Questions people ask
Is photoelectric the same as photoacoustic?
No. Photoelectric is the method used in smoke alarms; photoacoustic is a genuine CO2 measurement technique. The listing uses both terms for the same sensor, so one is a copy error.
What CO2 range does it cover?
400 to 5000ppm, which covers everything from fresh outdoor air to a badly ventilated room.
Does it need WiFi?
No. It is a standalone meter with a screen and an alarm, which makes it simpler than the app-based monitors here.
How does it compare with the SONOFF?
It is slightly cheaper and rated 4.4 against 4.2, but it has no smart-home integration, and the SONOFF states its accuracy more honestly.
How long do the batteries last?
The listing describes dual detection modes for extended standby; battery life in this class depends on how often the screen and alarm run.
How many ratings does it have?
717 at the time of collection, averaging 4.4 stars, with 70 per cent five-star and 7 per cent one-star.
Comments
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