Airthings Corentium Home vs Corentium Home 2: what changed

Inside, the two detectors work the same way. Airthings describes the radon sampling in both as a passive diffusion chamber: air drifts in on its own, with no fan or pump, and the sensor counts the alpha particles that radon and its decay products give off, which is what alpha spectrometry means. Neither needs a laboratory, and Airthings points out for the original that there are no lab fees and you can check the reading whenever you like.

Both run on batteries rather than a wall socket, so either can sit in any room. Both show averages on a built-in screen rather than one live number: the Corentium Home shows rolling short-term and long-term averages, and the Corentium Home 2 adds views up to a 30-day average and a long-term average covering up to a year. Airthings gives the same recommended operating range for both, 39 to 104°F with relative humidity below 85%, and describes the Corentium Home 2 as keeping the original's accuracy while adding smart connectivity.

Airthings sums up the changes as Bluetooth connectivity, the Airthings app, two bonus sensors and better battery life. In practice that means four things. First, power: the Corentium Home runs on three AAA alkaline batteries that Airthings rates for 2 years, while the Corentium Home 2 takes two AA batteries and is rated for up to 3 years when it is not connected, or up to 2 years with Bluetooth in use.

Second, the phone. The original has no app; everything is on its screen. The Corentium Home 2 connects over Bluetooth to the free Airthings app for graphs, and it can connect through Airthings SmartLink to an Airthings hub device for Wi-Fi access. Third, the extra sensors: the Corentium Home 2 also measures temperature and humidity, and Airthings markets it for basements and lower floors, where its humidity reading flags damp conditions. Fourth, the screen: after 30 days the Corentium Home 2 offers six views, the 24-hour, 7-day, 30-day and long-term radon averages plus temperature and humidity, and it returns to the long-term average after 5 minutes.

Airthings states its accuracy figures at 5.4 pCi/L (200 Bq/m³) for both. For the Corentium Home it gives about 10% after 7 days and about 5% after 2 months. For the Corentium Home 2 it states accuracy and precision within 10% after 7 days at that level, and after 4 days at 10 pCi/L (370 Bq/m³). These are the maker's own figures.

The independent picture differs. C-NRPP's 2024/25 consumer monitor evaluation, which put each device through four rounds of testing in four different sets of conditions, approved the Corentium Home and graded it A in all four rounds; Airthings' Canadian page also says the model is C-NRPP approved. The Corentium Home 2 was not included in that evaluation, so there is no C-NRPP result for it either way. Not being included is a fact about which devices took part, not a failed test. C-NRPP tested the Canadian version of the original, and we have not confirmed that the US model 223 is identical.

C-NRPP grade

C-NRPP grades each round by how far a monitor's reading was from the chamber's known radon level: A for an error of 10% or less, B for more than 10% and up to 20%, and so on down to E. Accuracy results explained sets out every monitor's grades.

Nothing about the newer model changes how the original measures. Its screen still shows a short-term and a long-term average, and the long-term figure is the one to act on. C-NRPP's advice for any consumer monitor applies to both: run it for at least 3 months, ideally in the heating season, in a room people use for at least 4 hours a day, and base a decision on the long-term average rather than a day's reading.

Airthings also notes a reporting feature on the original: you can generate a radon self-inspection report to document or share your readings. If what you miss is a phone history or a humidity reading, those are what the Corentium Home 2 adds. Either way, a consumer monitor cannot be professionally calibrated and is not approved by C-NRPP for use by radon measurement professionals, so a home sale may need a different test; check what your state accepts.

Neither comes out ahead. Each column below has four points drawn from what Airthings and C-NRPP state, so the choice rests on what you need.

Each has its own page with every specification and its evidence box: Airthings Corentium Home and Airthings Corentium Home 2. Every monitor we cover is on radon detectors and monitors, and the other Airthings pair is compared on View Plus vs Wave Plus.

1. 1Step 1 of 5:

   Pick the floor

   The lowest lived-in level of the home, in a room used regularly, such as a living room, playroom, den or bedroom, not a kitchen or bathroom.

2. 2Step 2 of 5:

   Pick a room people use

   A room occupied for at least 4 hours each day.

3. 3Step 3 of 5:

   Set the height

   At least 20 inches above the floor, away from drafts, high heat, high humidity and exterior walls.

4. 4Step 4 of 5:

   Keep clear of openings (Corentium Home 2)

   Airthings asks for at least 3 feet from the nearest door, window or air vent, out of direct sunlight and moisture, and not to move it during a measurement.

5. 5Step 5 of 5:

   Give it time

   At least 3 months, preferably in the heating season, and decide on the long-term average.

More on placement is at where to place a radon test, and on reading the result at continuous radon monitors.