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  • Writer's pictureDerek

CO2 Monitor- Aranet4 vs eBay?

Yes, it's a sign of the times I'm afraid. The world is getting smashed by Omicron in this seemingly never-ending pandemic; we have another risk mitigation tool. With many governments deciding that it is acceptable for loads of cases to be circulating in the community, we need to start taking the safety of our family into our own hands. Vaccines alone, including the third dose, whilst essential, will likely not save us. What we need is a multi-pronged approach, which compromises not only the vaccine but also:

  1. Wearing a high-quality mask (properly) at all times when out in public

  2. Social distancing

  3. Minimising trips to crowded indoor public spaces

  4. Testing and isolating if positive

  5. Ventilation

What does a CO2 monitor do? Well, it doesn't tell us if there is virus nearby. But what it does tell us is the quality of the air that we are breathing, ie. whether there is adequate ventilation. Outdoors is by far the safest and best ventilated, but there are times when we can't be outside, and it is important for us to measure the level of CO2 in the area we are in. Why? Because it gives us an idea of what sort of air we are breathing in. Poorly ventilated spaces means the air that has been breathed out by somebody else, will stay in the room for extended periods of time. And if that person has Covid, well, those nasties are going to still be in the room long after they've departed.

So now that we've established CO2 as a measure of ventilation but not presence of virus, what do we do with that information? Levels of <800ppm are considered to be ideal, whilst >1000ppm is a red flag and a signal to get out of there ASAP.

From my research, at least in Australia, the Aranet4 is the gold standard when it comes to personal, portable CO2 monitors. But it does come at a price. Around $355. But it is very accurate, and there is a smartphone app where you can adjust settings, calibrate the device, and chart the CO2 levels over the course of 7 days. The Aranet4 is extremely light, and uses 2AA batteries, with a battery life of 6-72 months, depending on the settings you choose. So running out of charge won't be an issue at all. With this piece of tech, I found that there were situations that I thought were well ventilated which weren't, and vice versa. The most shocking was inside a medical office, and inside my own car. The numbers got to scary-high levels.

How does the Aranet4 compare to those cheap, $30 devices that are sold in abundance on eBay, Amazon. etc? The one that I had for comparison, looked great and charged via USB-C, but was wildly inaccurate. The temperature and humidity levels were out, but worse, the CO2 level never budged above 450, no matter how stuffy the room was, even though the Aranet4 was reading real high. Apart from the obvious aspect that these cheaper devices (well, at least the one that I have) don't work, it is very dangerous. False reassurance that a room is ventilated when it is, in fact, not, is not good. I have flagged this to the seller of my particular product, but have so far yet to receive a personalised response. It's almost like they just jumped on the bandwagon with the aim of taking people's money without delivering a safe and accurate product. Not acceptable, in my books.

Anyway, I've been taking my Aranet4 everywhere, and it is, to put it mildly, eye-opening. I hate to see what the levels are in school (something that I'm quite anxious about to be honest, considering none of our kids have had three doses of vaccine, with our youngest only having had one dose), or in a workplace.

I know this all sounds very nerdy, but safety comes first these days. We have no other choice.

Take care of yourself.

Until next time,



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