Frozen radon exhaust when frost closes the outlet
The air leaving the pipe is moist. In extreme cold a collar of frost can form at the outlet, especially if the stack is short. Flow drops. The U-tube that showed suction moves toward zero.
Clear the outlet if you can do it without going onto a risky roof. If it ices every night, the installer extends or insulates the discharge. Do not shut the fan off until a thaw. Snow. Fan stopped.
The 4-day test is a first reading. The 91-day test covers the three-month minimum Health Canada asks for. Both are $59 before tax. Shipping, the return and the lab are included. Tax is extra. The PDF report goes out within 2 business days after the lab receives the detector.
Above 200 Bq/m³, mitigation starts with a quote. Gaz Radon is C-NRPP certified and ships kits across Canada. See the Canada test page.
Sources
