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

Not the cheapest for sure, but like many things, you tend to get what you pay for.In this case, for me, after over almost 3 years of continuous use a device that's:- reliable, accurate (tested against calibrated devices) and convenient- tested in NE USA and SE Asia, and even used carried in a bag through subway systems- battery lasted about 2 years- excellent reporting/charting app (7 days worth of readings - exportable as .csv/.xlsx) and bluetooth comms, flawless device firmware updatingEasily worth the money over time.

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.

A CO2 monitor tells you how much of the air you breathe is coming from other people's exhalations. If the CO2 level is too high, you need to leave the space, increase the ventilation, or use an air purifier to filter the air. It is the single most useful item to protect yourself from getting covid19 indoors.Among CO2 monitors, this one is outstanding. It is small and unobtrusive so you can carry it with you everywhere without upsetting people. It updates once a minute so you can get accurate timely readings. If you install the app, you can view graphs of CO2 concentration by the minute, along with temperature and humidity. You can use this information to figure out when you entered an indoor space and how well ventilated it was. The batteries last a long times (years?) so very convenient as well. And with one button you can upload the data to a spreadsheet (eg., on google drive) which allows you to more easily analyze it.Using the monitor has also allowed me to better understand ventilation. Simply opening the windows might not be sufficient. I noticed that when the interior temperature is lower than the outside temperature, the CO2 gets trapped in my house and I have to really open the windows wide and turn on the HVAC to achieve ventilation. Seriously an accurate timely CO2 monitor is the most useful anti-covid19 tool ever and this one is particularly good.

As someone who has evidently been suffering from extremely elevated CO2 levels for about 10 years (Yes, it was horrible and I didn't know), I have to say this is a great product and has literally saved my health and well being. From what I know this product is essentially a top of the line air monitor but it comes with a pretty hefty price. While I love this product I must also include that I originally started with a much much cheaper air monitor (Qingping) which after a couple months of using them in tandem, seems to be consistently within 50ppms of the Aranet. I do not regret the purchase of the Aranet because it has more sophisticated sensors and takes readings in a fundamentally unique when compared to my Qingping which gives me added confidence in the results. I have never felt better thanks to my new ventilation fan providing me fresh air throughout the day. I literally would have never been able to resolve this issue without the use of these air monitors. For me, they were worth every penny. My only complaint with the Aranet is the physical monitor itself doesn't seem to be able to display temperature in Fahrenheit instead ofcelsius, but that's not why i bought this monitor. Great product. Hope this helps.