SAF Aranet4 Home: Wireless Indoor Air Quality Monitor for Office or School (CO2, Temperature, Humidity and More) Portable, Battery Powered, E-Ink Screen, App for Configuration & Data History

I've owned several CO2 sensors. In particular, I've had 2 Awair Glow units, 1 first-generation Awair unit, 1 second-generation Awair unit, and a TIM10 CO2 sensor. Of these sensors, the TIM10 is my "gold standard" sensor, but it has the very, very annoying property of requiring AC power. Aranet4 promised to be a battery-powered CO2 sensor that could output data to an app. It delivers, but it requires calibration out-of-the-box, in my opinion. Measured against known good sensors (particularly my TIM10), my Aranet4 sensor read about 75ppm higher than the environmental level out-of-the-box. The app warns you that performing calibration will permanently erase the factory calibration data, which is somewhat scary, but I did it anyway. In order to validate that the calibration was successful, I had my trusted TIM10 sensor outdoors, connected to AC power, out of the sun, with the Aranet4 directly next to it, on a substantially windy day with extremely good air quality (as measured by PM2.5 and PM10 presence from AirNow and Purple Air). The floor, outdoors, in this configuration, as read by the TIM10 unit, was 380ppm of CO2. Before calibration, in the same environment, Aranet4 reported 480ppm. After calibration, Aranet4 reported within 15ppm of TIM10, which I considered a success, particularly given the rarity of having such a low reading. All of the Awair units bottom out at 400ppm. Following calibration, for the last few weeks, I've kept an eye on Aranet4 and TIM10 when they've been in the same room. There's approximately a 10-15ppm disagreement between TIM10 and Aranet4, which I consider a very acceptable deviation given that Aranet4 is battery powered, and TIM10 is AC powered. On the app side, Aranet4 provides a serviceable iOS app. The iOS app itself is perfunctory. It provides graphing, exporting data (as csv, including CO2, pressure, humidity, temperature, and date of sample), and basic reporting features. It doesn't support dark mode, though, as an example of its perfunctory nature. The app developers didn't consider the performance impacts that storing all of the data would have on the graphing component, though, so the app gets laggier the more data the sensor measures. You're also only going to get a week of data for historical measurement. Other details are worth mentioning beyond the sensor accuracy and app integration, though. E-ink, as a display type, is just awesome. It looks very nice, aesthetically. Each refresh blanks the screen temporarily, though. Keep this in mind, if you decrease the measurement interval (you can measure as frequently as once per minute). Also, there's no backlight, which is why the battery life is good, but keep this in mind too, if you want to see it in the dark. I've taken this sensor on an airplane, and it works great there too. It's just an incredible sensor to have -- you can pocket it or bring it somewhere in a backpack and still have CO2 measurements, where most sensors can't go. For travel, or just in general, it's a great device to have. After calibration, it measures very accurately, and I'm happy with my purchase all around. However, I'd say calibration is mandatory. I've included a screenshot of a graph made from the CSV, as well as the CSV data from the unit itself.

We have been using this carbon dioxide (CO₂) monitor for the past 18 months to check carbon dioxide levels in our home and work areas. CO₂ levels are a key measurement to assess the quality of indoor air and ventilation, which are important for minimizing the risk of virus transmission. One of the main reasons we bought it was to monitor how good the ventilation is in our indoor rooms. For example, in our home office, when the readings went up to 1,000+ ppm (parts per million), we noticed that our thinking slowed and we felt more sluggish. Decisions become more difficult to make. Apparently, our experiences match scientific studies that have proven that high levels of carbon dioxide can impair cognitive function and make it harder to think and be productive when CO₂ levels hit 1000 ppm and above. Thanks to this air quality monitor, we also noticed that if a second person enters a room, the CO₂ levels can increase quite rapidly just from our breathing. The CO₂ readings can sometimes double. We open a window to bring it back down to a good range. This monitor is small enough so that you can hold it in your palm and move it around easily. It looks both sleek and functional. Big bonus: it also provides temperature and humidity readings, and you can select either Fahrenheit or Celsius. To have all these readings all on one small device is very handy. It runs on two AA alkaline batteries, which are included. There is a helpful bar showing how much battery life is left. We have had our unit for 18 months, and after continuous use, we have not had to replace the batteries. The e-ink display digits are bright, easy to read, and large (roughly half an inch tall). The large digits and color bar allow you to quickly glance at the device from a distance and assess whether to take action to reduce CO₂ levels. There is an air quality bar that has three colors: green, yellow, and red. Each color corresponds to a different CO₂ level: green for normal (good), yellow for elevated (average), and red for high CO₂ levels (unhealthy). The second reason we purchased this monitor is to get an idea of how high the risk of respiratory virus exposure is. Higher CO₂ levels indicate poor ventilation, which can lead to higher airborne virus concentration. Scientists have found that people in a room with higher CO₂ levels are at a higher risk of virus infection than people in an identical room with lower CO₂ levels. Therefore, knowing when the CO₂ levels are high allows you to know when to reduce risk by opening windows to allow fresh air in, wearing a high-quality respirator mask, and/or reducing the time spent in that space. One feature we like is that you can use it with or without the app. So there is no pressure to use the app. Our only wish is that it came with a protective cover. In sum, this is a high-quality, reliable, and easy-to-use CO₂ monitor that allows you to continually assess air quality and ventilation. This was quite an investment, but well worth it. Highly recommended.

The aranet4 is such an excellent monitor, and really is the best bang for your buck in an accurate and easy to use monitor. We have used this in all the rooms of our home to measure air flow and how quickly C02 builds up - especially useful in the kitchen during various cooking processes and in the bedrooms overnight - but we have also brought it to work to measure the C02 and get an idea of the air flow in various offices as well. It's easy to set up, the battery life is excellent, and it's easy to bring with you anywhere. The app works well and is likewise a quick and easy setup. We keep this monitor in the main living area of our house and it's every easy to monitor when the C02 is accumulating and we need to crack a window or turn on an exhaust fan. It's been illuminating. This item is also very accurate, and more so than others and cheaper version. Totally worth the money and a reliable, trustworthy device for monitoring a really important aspect of our health.

Der CO2 Sensor ist gut und sicher verpackt. Macht einen wertigen Eindruck und sieht gut aus. Dank der Verwendung normaler Batterien und seiner geringen Größe kann man ihn einfach mal in ein anderes Zimmer stellen oder mitnehmen. Viele andere vergleichbare Geräte haben einen kurzzeitigen Akkubetrieb oder erfordern einen Netzanschluss. Die Bluetooth-Verbindung mit der zugehörigen App ging schnell und einfach. Die Verbindung ist stabil. Kein Re-Connect erforderlich wenn man zB außer Reichweite war. Die Anzeige am Gerät ist gut ablesbar. Meist schaue ich aber über die App, da hier auch der zeitliche Verlauf angezeigt wird. In der c‘t 27/2023 war ein Bericht über CO2 Messgeräte und der Aranet4 hat mich trotz des hohen Preises mein Interesse gefunden. Das hat sich im Betrieb bestätigt. Mit dem Gerät und der App bin ich sehr zufrieden. Was negativ zu erwähnen ist, ist die starke Preiserhöhung um €30 wohl zum Februar 2024. Ende Januar hab ich noch €179 bezahlt, aktuell kostet er €209. Versand kommt schnell aus Lettland (EU) mit €10 VK.

Living in a closed space with generally poor ventilation in an apartment, is the reason why I purchase this product. However , after been using it for over 2 weeks now, I have come into conclusion that most of us may not even need it because the CO2 in a closed space in my apartment rarely goes above 800ppm throughout the day. The only situation where it can go above 800ppm is when gas stove is used. However, carbon dioxide monitor or reader can be useful if you live in a rather tight space whereby there are three or more occupants as CO2 is mainly produced by respiration or breathing other than from burning gas. As you can see in the picture here, the screen on the aranet 4 is quite a bit sharper and contrasty than the inkbird and the design is more attractive due to semi transparent plastic case and the underlying board design is partially visible whereas inkbird has a bit of off-white coloration. The measurement is very similar to one another due to similar NDIR sensor used. As mentioned, the main deciding factor whether you need this or not is how many occupants in a space or how crowded the space is. More people occupying same space at same time, the higher the CO2 produced. For the app, I like how you can just drag along the chart to see the reading. However, aranet app only allows 7 days of data to be kept on the device before it gets overwritten where as the inkbird can keep data on the device for up to 30 days. Basically, aranet app is more polished , however, data storage is only limited to 7 days when set to 5 minutes measurement interval instead of 30 days (on device) to 1 year on inkbird (only when is synced to the phone). Addendum : Aranet has released a firmware in Dec 2023 that allows you set how long the data can be stored on the device and this depends the measurement interval, i.e. 2 minutes interval equivalent to 7 days of storage; 5 minutes for 15 days ; and 10 minutes for 30 days of storage . Besides CO2 readings, you will also get ambient temperature, humidity and atmospheric pressure readings. However, this device is not equipped with complete suite of air quality sensors, what is missing out here are quite substantial and these include volatile organic gas (VOC) , radon, particulate matters , carbon monoxide which are important parameters to determine the air that you breath is safe. And of course to have all these sensors included in an air quality monitor will costs a fortune for regular consumer. The Bluetooth range on the Aranet 4 is slightly shorter than inkbird from the distance I tested. 7-8 meters on inkbird vs 6 metres on aranet4. aranet 4 has a hidden feature of boosting it's Bluetooth range at presumably small cost of battery life by a toggle under Bluetooth setting of the app to about the same range as inkbird. One important thing when placing the double AA battery in, is quite different from other device, make sure you place the positive side first then only negative due to there is a plastic lip at the positive side. Battery is super long lasting due to energy efficient E ink display and low energy Bluetooth and especially interval measurement is set to 5 or 10 minutes. Downside to this is that you can only get Bluetooth connection to sync the data to phone rather than wifi and can't assess the data if not in the Bluetooth range or if away from home. Aranet claims there is a smart home integration app called homey but I guess it can be complicated to setup due to the integration is not mainstream like homekit or google home.

I sleep with my wife in a small room and I've always been curious as to the amount of CO2 that accumulates if we have the door closed. We soon discovered that closing the bedroom door with only one person sleeping sent the CO2 levels quite high. Needless to say because of our new monitor we now sleep with the door open. The bluetooth app is neat and keeps a running log/graph of your CO2 levels. The batteries are supposed to last for a very long time. .. Not much to complain about functionality wise. The low/med/high level indicators along with the precise reading display are nice and easy to read. Very pricey and only splurged on it because it was recommended by a family member. Glad I purchased it but I still smart when I think how much I had to pay for it. I would recommend to anyone who is concerned about the air quality within the home.

新型コロナウイルスが空気感染することが明らかとなり、換気が感染予防の大変重要な手段となって久しいですが、いろいろな換気モニターを使用してきて、結局、Aranet4 が一番まともで信頼できると思われます。乾電池駆動で低電流設計のため長期間安定して計測できます。スマホとのリンクも簡便で安定しておりいつでも状況をグラフで確認できます。スマホでは、本体には表示のない気圧変動も細かく観測でき、意外とこれがほかのセンサーにはないすぐれたポイントです。メーカーサイトのForamも活発で応答も早く、Feedbackが有効に働いていると思われます。値段が高いのが大変残念な、そして大きな欠点です。

Ce capteur est une merveille. Avec un affichage e-ink, le capteur consomme très peu. L’app permet d’avoir un historique des mesures et permet de régler certains paramètres comme la fréquence des mesures.