Airthings vs Aranet: Which Radon Detector to Buy

Airthings and Aranet make the two battery-powered radon monitors most Canadians end up choosing between. Both were independently tested by Health Canada's designated certification body. Both are good.

The short version: Airthings Corentium Home is the better buy for most people at around $180, because it is cheap, proven and needs no phone. Aranet RN+ is the better instrument at around $340, with a tighter accuracy specification and selectable averaging windows. Neither is a mistake, and the price gap is bigger than the quality gap.

The specification difference, in plain terms

Aranet RN+ publishes ±8% on its 24 hour, 7 day and 30 day averages. Airthings publishes ±10% after seven days and ±5% after two months. Those are the two numbers people compare, and they mislead slightly, because they are measured over different windows.

What matters in practice:

• At short windows, Aranet is tighter
• Over two months, Airthings claims ±5%, which is the best long-term figure on the list
• Over the timescale you should actually be testing, three months or more, the difference between them is smaller than the day-to-day variation in your house

If you are choosing based on which number is smaller, you are optimising the wrong variable. Testing duration affects your result far more than either specification.

What the Canadian lab data says

Both devices were in the C-NRPP 2024/25 consumer monitor performance report, tested at the Radiation Safety Institute of Canada's National Radon Chamber across four rounds: two near the 200 Bq/m³ Canadian guideline, one at 436 and one at 1,201, each running seven days.

C-NRPP's conclusion covered all six devices tested, Airthings and Aranet included: every one "demonstrated acceptable performance to be recommended by C-NRPP (an average performance grade of B or better)".

That is the most useful thing anyone can tell you about this comparison. Both brands passed independent Canadian testing. You are choosing between two devices that work, not sorting a good one from a bad one.

The round worth examining is the one run at 70% relative humidity to simulate a Canadian summer basement. Grades slipped there relative to the drier rounds. If your basement is damp for months of the year, that round is more relevant to you than the specification on the box.

Where they genuinely differ

Price

Around $180 for the Airthings Corentium Home against around $340 for the Aranet RN+. The Airthings Corentium Home 2, which adds Bluetooth and humidity sensing, sits between them at roughly $250.

That $160 gap buys a tighter specification and more control. It does not buy a different answer to "is my house above 200".

Whether you need a phone

The Airthings Corentium Home shows 12 hour, 24 hour and 7 day averages on the device with no app at all. For a lot of people that is the entire appeal.

The Aranet RN+ also displays on the device and lets you pick which window it shows, but its long-term history lives in the app.

If you want a device you can hand to an older relative, the original Corentium Home is the answer and it is not close.

Control over the averaging window

The RN+ can be set to 10 minutes, 24 hours, 7 days or 30 days. This is its most underrated feature. A short window while you experiment with ventilation, a long window for your real answer.

Airthings decides the windows for you.

Ecosystem

Airthings sells a range of connected air quality monitors, so if you want radon alongside CO₂ and VOCs in one app, that direction is better developed. Aranet is the more focused instrument.

Which one to buy

Buy the Airthings Corentium Home if: you want the cheapest independently tested device, you would rather not install an app, or you are testing one home once and acting on the result. This is the right answer for most Canadian homeowners.

Check the Corentium Home price on Amazon.ca

Buy the Aranet RN+ if: you want the tightest readings available without a subscription, you want to control the averaging window, or you are verifying that a mitigation system worked and want confidence in a before-and-after comparison.

Check the Aranet RN+ price on Amazon.ca

Buy neither yet if: you have never tested your home. A mail-in alpha track kit at $30 to $60 gives you a lab-analysed long-term average and answers the only question that matters first. Our DIY testing versus hiring a professional guide explains when each approach fits, and the DIY testing page compares kits directly.

The limit that applies to both

Neither device produces a measurement anyone official will accept.

C-NRPP states that consumer monitors "cannot be professionally calibrated and are not approved by C-NRPP for use by radon measurement professionals". They are excellent for finding out whether you have a problem and for watching what happens after you fix it. They are not evidence for a real estate transaction, a landlord dispute, or post-mitigation certification.

For any of those you need a certified radon professional, whichever brand is sitting in your basement.

Whichever you choose, run it properly

Radon moves with weather, soil conditions and how sealed your house is. A single week tells you very little.

C-NRPP recommends at least three months in place, ideally through the heating season, with decisions made on the long-term average. Health Canada recommends acting above 200 Bq/m³ as a long-term average, and acting sooner the higher the number goes.

For the full field, including plug-in options and the mail-in kits worth considering first, see Best Radon Detectors in Canada 2026 and our guide to interpreting your radon test results.