After a radon system the fan is not the confirmation
A system that pulls under the slab and exhausts above the roof lowers radon while the fan runs and the pipe stays sealed. The indicator or the manometer shows suction. It does not give a number in Bq/m³.
Confirmation is a new test in the same room as before the work, at the lowest lived-in level, over 91 days, during the heating season. A 48-hour reading on installation day reassures the schedule. It does not replace the season. In the 2012 survey, Health Canada spoke of acting within two years between 200 and 600, and within a year above 600: the retest says whether the action was enough.
When to start again
After an addition, a new basement floor, or a replaced fan, retest. The usual frequency is in how often to retest. Switching the fan off in summer “to save electricity” puts the gas back in circulation as soon as the house closes up.
The electricity bill is not the test
The fan’s consumption is a separate calculation: electricity cost. The pipe route: where the pipe runs.
Reference points: Health Canada, what you need to know about radon and the 200 Bq/m³ guideline. The two-year timeline between 200 and 600, and one year above 600, comes from Health Canada’s guide for radon measurements in homes.
The 4-day test gives a first reading. The 91-day test covers the three-month minimum Health Canada asks for. Both are $59 before tax: shipping, return and the laboratory are included, taxes extra. The PDF report is sent within 2 business days after the laboratory receives the detector.
Above 200 Bq/m³, mitigation is confirmed with a quote. Gaz Radon is C-NRPP certified for measurement and mitigation.
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