What it is and how it works
The sensor, the sampling and the readings
Airthings describes the radon sampling as a passive diffusion chamber and the detection method as alpha spectrometry. Air drifts into the chamber on its own, with no fan or pump, and the sensor counts the alpha particles given off as radon and its decay products break down. Nothing goes to a laboratory, and Airthings points out that there are no lab fees.
The screen is the whole interface. Airthings says it shows rolling short-term and long-term average concentrations of radon, so you check the reading by looking at the device. There is no Bluetooth, Wi-Fi or app. Airthings also notes that you can generate a radon self-inspection report to document or share your readings.
Airthings publishes a measurement range of 0 to 500 pCi/L (0 to 9,999 Bq/m³), and gives its US version the model number 223 and its European version 244. The detector runs on three AAA alkaline batteries, which Airthings rates for 2 years, so it can sit in any room without a cable.
It now has a successor. The Corentium Home 2's page lists the original as the previous model, and Airthings' Canadian page says the original is no longer available there, while its US store lists it for sale as of October 2026. The newer one adds Bluetooth and the Airthings app, temperature and humidity sensors, and longer battery life on two AA batteries.
C-NRPP's own listing for the model gives the same stated accuracy, ±10% after 7 days at 200 Bq/m³ and ±5% after 2 months, and lists its reading periods as 12 hours, 24 hours and 7 days, with the first reading taking 24 hours. That makes it slower to show a first number than plug-in monitors that update every 10 minutes; it is built for the long view, which is the view that matters for a decision about fixing a home.
C-NRPP tested the original in its 2024/25 consumer monitor evaluation, which put each device through four rounds of testing in four different sets of conditions, and approved it. C-NRPP tested the Canadian version; we have not confirmed that the US model 223 is identical.
Independent evidence
C-NRPP 2024/25, recalls and studies
- C-NRPP 2024/25
- Approved in C-NRPP's 2024/25 consumer monitor evaluation
Listed by C-NRPP as "Airthings Corentium Home". Results published May 2025.
- Grade by round
- Round 1A218 Bq/m³, 23°C, 28% RH, 7 days
- Round 2A210 Bq/m³, 29°C, 70% RH, 7 daysRead from the bar; no letter printed
- Round 3A436 Bq/m³, 23°C, 36% RH, 7 days
- Round 4A1,201 Bq/m³, 23°C, 35% RH, 7 days
C-NRPP grades each round by measurement error: A is 10% or less, B more than 10% and up to 20%, C more than 20% and up to 30%. It recommends devices that average B or better.
- Earlier round
C-NRPP's 2023 report listed “Airthings Corentium Home” as having passed its performance test.
- Recalls
- No Health Canada recall or advisory names this device.
- Peer-reviewed studies
- We found no peer-reviewed comparison that names this model.
- Notes
- C-NRPP's chart prints no letter over the Corentium Home's round 2 bar; the bar is drawn at the same height as its A bars, so round 2 is read as A from the bar.
- C-NRPP links the Canadian product page (airthings.com/en-ca/home-bqm). C-NRPP tested the Canadian version; we have not confirmed the US version is identical.
C-NRPP is the Canadian National Radon Proficiency Program. Its 2024/25 results were published in May 2025.
How C-NRPP says to use any consumer monitor
- Leave it in place for at least three months, ideally through the heating season, when indoor radon tends to be highest.
- Put it in a room someone uses for at least four hours a day.
- Decide about fixing your home from the long-term average, not a single day or week.
- If you can only run a monitor for less than 91 days, follow up with a long-term test.
What the manufacturer says
Airthings's own statements, attributed
- Airthings saysAirthings states accuracy and precision of about 10% after 7 days and about 5% after 2 months, at 5.4 pCi/L (200 Bq/m³).
- Airthings saysAirthings states that the Corentium Home runs cable-free on batteries for up to 2 years.
- Airthings saysAirthings describes the Corentium Home as officially C-NRPP approved for use in Canada.
- Airthings saysAirthings describes the Corentium Home as a simple, always-on radon detector with short and long-term radon levels on an integrated LCD display.
These are Airthings's own statements, attributed to it. They are not our findings, and we have not tested this product ourselves.
Who it fits
Good fit if, and look elsewhere if
Good fit if
- You want a model that was itself graded in C-NRPP's 2024/25 evaluation.
- You want readings on a screen with no app, phone or wireless connection at all.
- You want a battery device you can place in any room without an outlet.
- You already own one and want to know what its screen is telling you.
Look elsewhere if
- You want the newer model Airthings presents as the successor; that is the Corentium Home 2.
- You want graphs on your phone or readings from away from home.
- You also want temperature and humidity in the same device.
- You need a result for a home sale; check what your state accepts before relying on any consumer monitor.
Setup and placement
3 steps
- Airthings' recommended operating conditions are 39 to 104°F with relative humidity below 85%, so a very damp basement corner is not the place for it. The detector measures 4.7 by 2.7 by 1.0 inches and weighs 5.2 oz with its batteries.
- The EPA's general placement guidance applies: the lowest lived-in level of the home, a room used regularly but not the kitchen or bathroom, at least 20 inches above the floor, and away from drafts, high heat, high humidity and exterior walls.
- C-NRPP's advice for any consumer monitor is to place it in a room occupied for at least 4 hours a day, test for a minimum of 3 months, preferably during the heating season, and decide on the long-term average. With less than 91 days of data, it recommends following up with a long-term test.
For where any radon test or monitor should sit in a home, see where to place a radon test.
What is in the box, and what it costs to run
Contents, warranty and running costs
In the box
Airthings lists the package contents as the radon detector, three AAA alkaline batteries and a user manual. Airthings also describes a free 5-year extended warranty on its consumer monitors, with registration required within 30 days of purchase.
Running costs
There is no lab fee, app or subscription. The running cost is three AAA alkaline batteries, which Airthings rates for 2 years. If you buy from a seller other than Airthings, check what the listing says about condition and warranty.
Questions people ask
6 questions, answered
Is the Airthings Corentium Home discontinued?
Not in the United States as of October 2026: Airthings' US store lists it for sale. Airthings' Canadian page lists it as no longer available, and the Corentium Home 2's page calls the original its previous model.
What is the Corentium Home model 223?
Model 223 is Airthings' number for the US version of the original Corentium Home; the European version is model 244. The Corentium Home 2 is a different model, number 325.
How do I read the Corentium Home?
On its screen, which Airthings says shows rolling short-term and long-term averages. The long-term average is the figure to compare with the EPA's guidance: fix at 4 pCi/L, and consider fixing between 2 and 4 pCi/L.
Is the Corentium Home C-NRPP approved?
Yes, in the 2024/25 evaluation, with an A in each of its four rounds; Airthings' Canadian page also describes it as C-NRPP approved. C-NRPP tested the Canadian version, and we have not confirmed that the US model is identical.
Does the Corentium Home have an app?
No. It has no wireless connection; everything is on its screen, including the short-term and long-term averages C-NRPP's listing describes. The Corentium Home 2 adds Bluetooth and the Airthings app, along with temperature and humidity sensors and longer battery life. If you want a record of the readings from the original, Airthings describes a self-inspection report you can generate to document or share them.
How long do the batteries last?
Airthings rates three AAA alkaline batteries for 2 years.
What to do next
- See every continuous monitor we coverEach with the same fields and its evidence.Go
- Place it where it countsThe lowest lived-in level, away from drafts, at least 20 inches up.Go
- Read your resultWhat a number in pCi/L means and what the EPA says to do next.Go
- Testing for a home sale?Find radon measurement professionals in our directory.Go