HOME or PRO? Which Aranet4 is right for me?
HOME - Ideal for private use or in a small business, from 1 to up to 4 or 5 units. Displays the real time CO2 level on the device, updated up to every minute. Will Bluetooth to the Aranet app, so you can track up to 7 days of readings at a time from your device and/or the Aranet Display app, so you can display it on a screen for your customers to see what excellent air quality you are providing. Buy HOME.
PRO - Ideal for larger installations from 3 up to many hundreds of units in a business, school or other institution. Like the HOME, the PRO displays the real time CO2 level on the device, updated up to every minute. The PRO also has the Bluetooth capability of the HOME, but in addition incorporates a radio wireless link to a base station (up to 2km away), from which the activity of all the linked PRO units can be monitored at once. This information can also be uploaded to the cloud (with extra licence payment) for real-time monitoring remote from the site. Buy PRO.
Here's a useful little leaflet which summarises the features. Just click on the picture to open it in a new window:
September 11th 2021, click to read: September 22nd 2021, click to read:
I want a quick summary about the Aranet4
The Aranet4 is a small, battery powered CO₂ sensor, which also measures temperature, humidity and atmospheric pressure. Depending on the model, HOME or PRO, it will connect via Bluetooth to a smartphone app or via wireless to a dedicated base station, alerting you to changes in environmental CO₂ level. This allows you to ensure that your indoor air remains of the highest quality. You can download the Aranet4 User Manual and datasheet here.
This video presents a handy one minute summary of the Aranet4:
Why is the Aranet4 better than other, cheaper CO₂ monitors on the market?
1. NDIR versus MOS sensor
The Aranet4 uses NDIR (non-dispersive infrared) technology to directly measure CO₂ . Cheaper monitors use the much less accurate MOS (metal oxide semiconductor) method of measuring volatile organic compounds to only estimate CO₂ level. You can learn more about this and see a real world comparison between NDIR and MOS sensors by clicking on the image below and scrolling down to "Sensors":
2. Pairs to a phone or a base station
The Aranet4 HOME pairs to the Aranet phone app via Bluetooth. The Aranet PRO pairs to its base station via wireless. This gives you a graph of readings over time and allows you to easily see the effect of different interventions to improve ventilation. See an example here in one of the Aranet Stories, In a bedroom.
3. Small and stylish and the battery lasts forever
The Aranet4 fits in the palm of your hand, sits stylishly on a surface or on the wall with its special security wall mount, or even in a pouch on your belt. Its e-Ink display draws hardly any power and the battery will last for up to two years of continuous use. It is unobtrusive and does not look like a big, ugly industrial measuring device.
How do I pair my Aranet4 with my smartphone?
It's easy. You pair it like you pair any other Bluetooth device with your smartphone. This one minute video shows you exactly how to do it:
How often do I need to calibrate the Aranet4 and how do I do it?
If the device goes outside then it will calibrate itself automatically once a week by presuming that its lowest measurement corresponds to the CO₂ level in outside air.
But if it is fixed to a wall and doesn’t go outside, then how often should a HOME or PRO unit be calibrated? This is slightly a “how long is a piece of string” question. Most devices remain consistent for long periods and you don’t want to be calibrating them unnecessarily.
One suggestion would be to log a note of the reading for each unit before installation by placing them all outside: if all are showing similar readings +/-50 ppm in the mid 400s ppm then they are all working correctly. Then log the readings of each of them once they have been placed in the desired location/room, and once that room has been ventilated and the air as fresh as it can be expected. This then gives you a reference level for that space when it is well ventilated. If in the future the readings deviate significantly (>100-150ppm) from the reference level at a time when the space should be well ventilated then there are two options: either the device needs recalibrating or the ventilation has worsened for some reason, such as a failed ventilation unit.
This two minute video shows you more about recalibration:
Tell me about using the Aranet4 to improve air quality in schools and universities
Air quality is vitally important in educational settings for two reasons. Firstly, poor air quality increases the risk of transmission of airborne infectious diseases such as COVID-19. Secondly, there is good evidence that high CO₂ levels reduce cognitive function and concentration and cause sleepiness at levels which are not very elevated. You can read more about this at our page Why measure CO2? You will find a lot of useful information on ventilation and filtration at our page How do I protect myself?
Click on this leaflet to see how you can use the Aranet4 PRO to
monitor air quality across an entire educational establishment:
This useful guide from Harvard University tells you how to check ventilation rates in classrooms:
This one hour webinar takes you in detail through the theory behind classroom ventilation, research showing the effects of high CO₂ levels on cognition in schoolchildren (from 22 minutes 20 seconds) and practical ways to measure and improve air quality in the classroom:
Professor Allen with a thread of details and tips for teachers going back to school: