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Aranet4 Home Sensor Review

Updated on March 7, 2023
Written by
Danny Ashton
Danny is the founder of HouseFresh and has been writing about air purifiers and indoor air quality since 2010. He is our lead tester, conducting all the tests we use to evaluate air quality products. That is why you will always see his name attached to our reviews.

Our verdict

The Aranet4 is currently the best portable CO2 sensor on the market, but it doesn’t come cheap. If you need to evaluate Covid-19 risk or travel regularly, this is the monitor I recommend.

It’s known that high CO2 levels can cause cognitive impairment. But it’s also been shown that CO2 levels pose a proxy of risk of catching air-borne viruses like COVID19. Having precise data on CO2 levels can be a great way of understanding air quality in homes, offices and even schools. 

Many cheap CO2 monitors are inaccurate or hard to use, but one of the most recommended sensors around is the Aranet4. Aranet is a SAF Tehnika JSC brand traded on the Baltic Nasdaq that had a revenue of 33 million euros last year. Their big innovation is using a Non-dispersive infrared sensor (NDIR) that is typically used in industry and is the most accurate CO2 sensor currently available. 

That sensor combined with an e-ink screen gives a maximum battery life of up to seven years! In comparison, the cheaper Qping Lite has a maximum battery life of only four hours. 

There are two versions — the Home and the Pro, with very similar features. The pro edition is meant to be used with a base station and other units, while the home version works alone. This is the version we reviewed. 

Why trust this review? We bought the Aranet4 Home with our own money, so we have zero bias and can share exactly what we like and, more importantly, what we didn’t like about this air quality sensor.

TL;DR The Lowdown on the Aranet4 Home Sensor

If you don’t want to read my entire 1500-word review, then check out my key findings about the Aranet4 below:

What We Really Like:

Battery life of up to seven years when using lithium AA batteries
👍 Measurements every 10 minutes
👍 E-ink display is easy to see in sunlight
👍 Simple App has good UX and the ability to export data for any timeframe
👍 NDIR sensor that is currently the best CO2 sensor on the market
👍 Small portable unit that can easily be left in a bag for continuous tracking while traveling

What We Think Could Be Better:

👎 Not waterproof, and I found the battery cover did come off easily when it moved around in my bag
👎 Price of $250 is not affordable for many people
👎 Would be great also to get a particle sensor in a future version

The Specifications

Accurate CO2 sensor combined with high-end battery life thanks to its e-ink screen.

HouseFresh Rating:★★★☆☆
Air quality factors detected:CO2
Sensor used:Non-dispersive infrared sensor
Power requirements:Battery-powered
Battery life:4.8 years using alkaline battery or 7 years using lithium battery
Mounting type:Table top
Dimensions (in inches / in cm):‎2.76 x 2.76 x 0.94 in (7.01 x 7.01 x 2.38 cm)
Weight (in pounds / in kg):0.23 lbs (104 g)

Pocket Design

The Aranet4 Home has a super-portable design, with the main focus being the e-ink display. It’s small enough to hold in one hand and thin enough to keep in a bag without taking up too much space. 

We recently got a chance to review the Qingping Lite, which includes a CO2 sensor and particle sensor. It’s similar in size, although the Qingping is much thicker than the Aranet4.

Introducing the Aranet4 Sensor

The stand-out feature of the Aranet4 is the combination of a Bluetooth 5.0 CPU, the BMD-30/39 series and the first NDIR sensor that uses LED’s from Senseair.

The Aranet4 is powered by two AA batteries and can be used with Alkaline and Lithium. Lithium batteries give the most extensive battery life of up to seven years if you only record CO2 every 10 minutes. 

Simple Controls 

You can use the Aranet4 with the e-ink display, which updates regularly to show you the temperature, humidity and CO2 level. You’ll get a score of Good, Average and Unhealthy.

It’s super easy to use the Aranet4 in standalone mode, but you get much more information when you connect it to your Apple or Android phone. I tested the Aranet app on Android using my Samsung S23 ultra. When you install the App, you don’t just see current sensor data, but also historical data. 

By default, the App will report CO2 levels every five minutes, but you can adjust this. Bear in mind that increasing the regularity of tracking will decrease battery life. 

Compared to the many apps we have tested for the smart air purifiers we review, the Aranet app is up there with the best, such as the Dyson Link app for example. 

After using the app, I found myself leaving the sensor in my bag instead of getting it out to read the e-ink display. This is super useful when traveling, especially if you are wearing a mask and trying to avoid contamination with Covid-19. You can just check your phone rather than getting out the entire unit to know the current CO2 level and, thus, the Covid-19 risk.

How the Aranet4 Performs

I got a chance to test the Aranet4 in my local area and was impressed with how quickly the sensor would change, even when it was just two people talking in a reasonably sized room. Understanding CO2 levels allowed me to take action in real time and reduce it by opening windows and doors.

The big reason that many people will get a CO2 sensor like the Aranet4 is to understand risk when traveling, as CO2 levels can rise dramatically on public transport and planes. I tested the unit on a long-haul flight to Buenos Aires over the holiday period.

You can see from the graph how the CO2 levels peaked during the initial take-off stage and then didn’t drop below 1900 ppm until we left the first flight. I was surprised by this and wondered if the filters in use were faulty as they should go down much further, but it shows you how important wearing a mask is on flights. The risk of air-borne disease is clear, based on these CO2 levels.

Exporting Data

One of the big benefits of using the Aranet4 App is that you can export data for any time frame. I used my long-haul flight data and Flourish to create the interactive chart below:

The ability to export data is an important feature. The Aranet4 app makes this super easy without the challenges I found with the Purpleair indoor sensor, which requires using an external tool to obtain the data.

Bottom Line

The Aranet4 is the best portable CO2 sensor on the market due to its high-quality sensor and clever design that allows for a very long battery life — years compared to the hours you get with combined air quality sensors like the Qingping lite.

The big downside to the Aranet4 is the price, as it’s nearly $250, so it is far from affordable for many. Still, if you travel regularly or need to know the risk of Covid-19, then you can’t get better than the Aranet4. 

About the author

Danny Ashton

Danny is the founder of HouseFresh and has been writing about air purifiers and indoor air quality since 2010. He is our lead tester, conducting all the tests we use to evaluate air quality products. That is why you will always see his name attached to our reviews.