Aranet Radon Plus Sale: Our Top-Ranked Radon Monitor Is 24% Off Through Sept. 27, Just Ahead of Heating Season

The right way to compare radon tests is cost per decision-grade answer. On that measure, a single-use long-term kit is hard to beat for one test, and a monitor wins the moment you test more than once.

The AccuStar Canada 1AT alpha-track kit, our Best Value pick, costs about $48. It sits in your home for about three months, goes back to a lab by mail, and returns a report roughly two weeks later. It gives you one long-term average. The next test means buying and mailing another kit.

The discounted Radon Plus costs about as much as four of those kits. It gives you every test after the first at no extra cost, plus a running picture of how radon moves by day, week and season.

Retesting is more common than most owners expect. Health Canada warns that energy retrofits can raise indoor radon by cutting air exchange, and cites a U.S. Department of Energy assessment that found a 22% average increase after retrofits. New windows, spray foam, a finished basement and a new mitigation system are all reasons to test again.

If your situation sits in the first row, skip the sale and buy the kit. That is the same conclusion our evaluation reached, and a discount does not change it.

For a deeper look at the kit-versus-professional trade-off, see our guide to DIY radon test kits versus professional radon testing.

The timing argument rests on one Health Canada rule. A long-term radon test must run at least 91 days, and at least 91 days of it should fall in the heating season, when indoor radon levels are typically higher. Health Canada's measurement guide recommends basing any decision to reduce radon on a test of that length.

Note what the guide does not say. It defines the heating season as the colder months when heating appliances run, not as fixed dates. In much of the country the heat is on by October; in milder regions it can come later. Start the clock when your heat is running regularly, not when the calendar says so.

Here is how the sale lines up with that window:

• By Sept. 27: Order before the sale ends. Aranet processes orders within two working days and ships by DHL Express.
• Early October: Set the monitor up on the lowest lived-in level once the heat is on, and ignore the first week of readings.
• Early November: About 30 days in; make your first data export.
• Dec. 31 to early January: A test started Oct. 1 reaches 91 days on Dec. 31. Export again and calculate the average.
• The rest of winter: Leave it running. A longer heating-season average is a better average.

November is Radon Action Month in Canada, and the Lung Health Foundation notes that long-term exposure to high radon is the leading cause of lung cancer in people who do not smoke. A monitor ordered this week is already a month into its test by then.

The odds are not remote. The Evict Radon national study puts 17.8% of Canadian residential buildings at or above Health Canada's 200 Bq/m³ guideline. For single-detached houses on their own, the same research finds one in five.

To see how your region compares, our breakdown of radon levels by province maps the higher-risk areas.

Reading the result

Compare your 91-day-plus average with Health Canada's guideline of 200 Bq/m³. At or above it, the next step is a C-NRPP-certified mitigation professional, not another test. Below it, you have a baseline, and the same monitor becomes your retest tool the next time the house changes.

Most homes need one Radon Plus on the lowest lived-in level. That single device carries the decision, and the bundles only make sense when they answer a second question.

The Radon One is the cheaper sibling, and the sale makes it tempting at $174.04 with the code. It is rated at ±10% on its averages against ±8% for the Radon Plus, and it does not appear on C-NRPP's approved list. That makes it a companion, not a substitute. If you buy one, the Radon Plus stays on the lowest lived-in level as the monitor you make decisions from, and the Radon One goes upstairs or into a second suite for comparison.

Radon Monitoring System, $361.95 with the code. One Radon Plus and one Radon One. Worth it for homes with a basement suite, a lived-in lower level plus a main floor, or a family that wants to watch both levels.

Basement Risk + Daily Air Control Kit, $369.08 with the code. One Radon Plus and one Aranet4 HOME. At sale prices the two devices bought separately total $414.40, so the bundle saves another $25.90 if you already wanted a CO2 monitor for a bedroom or office.

The larger systems, $532.24 and $539.36 with the code. Add a second Aranet4 or a Radon One on top. These suit large homes where air quality varies room by room; they add nothing to the radon decision itself.

If you are weighing the ±8% and ±10% ratings, our look at how accurate consumer radon monitors are in Canada explains what those figures mean in practice.

Aranet lists the contents of its radon-only bundle on the Radon Monitoring System page, including the one-year warranty extension for the Radon One.

Buying direct from a Latvian company's web store is not the same as clicking buy on Amazon.ca, and the differences belong in the price comparison.

Aranet's sales terms state that web-shop prices exclude taxes and shipping, and that customers are responsible for any import customs and taxes. Orders are processed within two working days and ship by DHL Express to addresses outside the EU and U.S. There is no shipping to PO boxes.

Four more terms are worth reading before you check out:

Returns: Canadian residents buying as individuals can request a refund within 60 days of payment, provided the product is unused and in its original packaging.

Cancellations: Once Aranet confirms an order, cancelling it carries a 20% fee. Decide before you pay, not after.

Warranty: 24 months as standard, extended by 12 months if you agree to receive Aranet's email updates, either at checkout or when you register the product. A unit that fails within 30 days is replaced as dead on arrival.

Service: North American warranty returns ship to SAF's U.S. office in Colorado.